How Intense Will Storms Get? New Model Helps Answer Question

How Intense Will Storms Get? New Model Helps Answer Question

ScienceDaily (July 9, 2008) — A new mathematical model indicates that dust devils, water spouts, tornadoes, hurricanes and cyclones are all born of the same mechanism and will intensify as climate change warms the Earth's surface.

The new equation, developed by University of Michigan atmospheric and planetary scientist Nilton Renno, could allow scientists to more accurately calculate the maximum expected intensity of a spiraling storm based on the depth of the troposphere and the temperature and humidity of the air in the storm's path. The troposphere is the lowest layer of Earth's atmosphere.

This equation improves upon current methods, Renno says, because it takes into account the energy feeding the storm system and the full measure of friction slowing it down. Current thermodynamic models make assumptions about these variables, rather than include actual quantities.

"This model allows us to relate changes in storms' intensity to environmental conditions," Renno said. "It shows us that climate change could lead to increases in how efficient convective vortices are and how much energy they transform into wind. Fueled by warmer and moister air, there will be stronger and deeper storms in the future that reach higher into the atmosphere."

Renno and research scientist Natalia Andronova used the model to quantify how intense they expect storms to get based on current climate predictions. For every 3.6 degrees Fahrenheit that the Earth's surface temperature warms, the intensity of storms could increase by at least a few percent, the scientists say. For an intense storm, that could translate into a 10 percent increase in destructive power.

Renno's model is what scientists call a "generalization" of Daniel Bernoulli's 18th-century equation that explains how airplane flight is possible. Bernoulli's equation basically says that as wind speed increases, air pressure decreases. It leaves out variables that were considered difficult to deal with such as friction and energy sources (which, in the case of a whirling storm, is warm air and condensation of water vapor.) And in certain idealized situations, omitting that information works fine.

But by including these additional variables, Renno was able to broaden Bernoulli's equation to apply it to more general phenomena such as atmospheric vortices.

"The laws of physics are generally very simple," Renno said. "When you make assumptions, you are not representing the simple, basic law anymore. If you don't make assumptions, your equations have those simple, basic laws in them. It gets a little more complicated to get to the solution, but you don't introduce error, and you answer is more elegant, more simple."

Renno's work bolsters studies by others who say hurricanes have grown stronger over the past 50 years as sea surface temperatures have risen. This effect has not been extreme enough for humans to notice without looking, scientists say. Hurricane Katrina and Cyclone Nargis were not the most intense storm to hit land in the past half century. Other factors contributed to the devastation they caused.

This new model helps explain the formation of spiral bands and wall clouds, the first clouds that descend during a tornado. It's clear now that they are the result of a pressure drop where the airspeed has increased.

Renno says unifying convective vortices from dust devils to cyclones will help scientists better understand them.

"This is the first thermodynamic model that unifies all these vortices," he said. "When you unify them, you can see the big picture and you can really understand what makes them form and change."

A co-investigator on NASA's Mars Phoenix Lander mission, Renno has used his new model to calculate the intensity of dust storms in Mars' polar regions. He found that at the Phoenix landing site dust storms can have winds in excess of 200 mph.

Renno is an associate professor in the Department of Atmospheric, Oceanic and Space Sciences. Andronova is a research scientist in the Department of Atmospheric, Oceanic and Space Sciences.

WEATHER NOTE

Spotting Storms?

This is from a Wisconsin storm spotter/chaser on June 27, 2008. Talk about an unusual radar target!

"My bother called from Antigo to say he has been watching three triangular shaped UFO's flying a little north of Antigo the past hour. I don't have time to look outside but check out this radar loop from Green Bay.."

You never know......

World weather expert says El Nino, La Nina outlook mild

The World Meteorological Organisation said Tuesday that 2008 was proving a year of respite from natural climatic phenomena identified by scientists as causing havoc with weather patterns.

The effects of El Nino and La Nina, respectively the warming and related cooling of Pacific sea surface temperatures, are felt in many parts of the globe, and have been blamed for a lengthy drought in Australia, flooding in the Horn of Africa and Bolivia, and more severe winter monsoons in South Asia in 2006-2007.

However, WMO official Rupa Kumar Kroll said that effects over the coming months are expected to be mild.

"Near neutral conditions are considered the most likely outcome for the middle part of the year and shortly thereafter," Kroll said, adding that La Nina "gradually weakened from its peak strength in February."

"Rapid development of El Nino or re-development of La Nina is not considered likely for the middle part of the year," he said.

The expert nevertheless cautioned that other factors which also influence seasonal climatic patterns could still trigger extreme weather conditions.

MARITIME NOTE

Riverdance ferry contractors praised after Cleveleys clear up

The contractors charged with cutting up the stricken Riverdance ferry have been praised for their work in keeping the beach clear of oil.

Nearly all of the oil has now been removed from the ship by Hancock’s Contractors Ltd and sub-contractor PGC Demolition Ltd, and the firms have been congratulated for their work.

Hugh Shaw, the secretary of state's representative for the operation, said: “The progress that has been made during the operation has been excellent and we are delighted that the beach has been kept free of oil.

“The contractors have gone to a great effort on the environmental side of things and they deserve full credit for that.”

Work is set to start soon on the removal of the engine and the remaining fuel tanks from the vessel, which ran aground just south of Cleveleys on January 31.

Cruise West already under Coast Guard watch
FLEET OPERATOR: Ships are being inspected and crew members questioned.

By JAMES HALPIN

The number of mishaps aboard Cruise West vessels so far this season has landed the company on a special program to review the ships' safety and maintenance procedures, according to the U.S. Coast Guard.

Seattle-based Cruise West ships have so far suffered three mechanical failures and two groundings, including the most recent that took place Monday morning when the Spirit of Glacier Bay ran aground in Tarr Inlet near its namesake bay.

The Coast Guard began talking to the company about the trend after its ships suffered the second mechanical failure of the season, said Capt. Scott Robert, Coast Guard sector Juneau commander.

Mechanical problems are common on ships, and the Coast Guard in Alaska responds to hundreds of such calls each season, he said. But the number specifically on Cruise West ships this season prompted the extra attention, he said.

"After the third mechanical failure and the (first) grounding is when we started to take a very proactive approach on looking at the safety systems on board those vessels," Robert said. "These safety stand-downs are above and beyond what we, the Coast Guard, typically do with this industry."

The Coast Guard frequently holds surprise spot inspections and evaluates vessels at the beginning of the season, Robert said. The "safety stand-downs" are an added layer of oversight to promote safety and prevent serious accidents, he said.

As part of the plan, all of Cruise West's ships are being inspected by Coast Guard personnel, who are examining safety plans, equipment and maintenance policies, Robert said. The boardings also entail talking to crew members to improve their awareness of safety conditions, he said.

Cruise West officials are working in partnership, with its vice president "actively participating" in the stand-downs, Robert said. The boardings are scheduled in advance and take about two or three hours on average, he said. They are being held wherever the ships are -- in Alaska and elsewhere.

"This is a Coast Guard-wide issue," Robert said. "This is a combined, overarching look (at) Cruise West across the entire Coast Guard."

The agency plans to continue with the stand-downs until it is convinced Cruise West vessels are being operated and maintained safely, Robert said.

Jerrol Golden, spokeswoman for Cruise West, which operates nine small cruise ships, would not comment on the Coast Guard program, though she said safety is a top priority for the company. She stressed none of the incidents this season involved any injuries.

"Each incident is different, and there's definitely lessons learned immediately," she said. "There's no doubt the management system is under review by us, for sure."

She would not elaborate.

Have a really great weekend!

RS

New Wind Measurement Technology May Help Olympic Sailing, Aviation and Weather Forecasting

New Wind Measurement Technology May Help Olympic Sailing, Aviation and Weather Forecasting

ScienceDaily (July 3, 2008) — A team of researchers at the Ocean University of China has developed and tested a mobile lidar (light detection and ranging) station that can accurately measure wind speed and direction over large areas in real time -- an application useful for aviation safety, weather forecasting and sports.

The mobile lidar station can measure wind fields more accurately, which could help world-class athletes compete in international competitions, such as the Olympics. Ocean University is in Qingdao, which is hosting the sailing competitions of the XXIX Olympic Games and the Beijing 2008 Paralympic Games, and this technique is being tested in conjunction with the event.

"Wind is non-uniform even in a small sailing field," says Professor Zhi-Shen Liu of the Key Laboratory of Ocean Remote Sensing, Ministry of Education of China, Ocean University of China, who led the research. "Athletes could maximize their performances if they have the most accurate information to help them capture the wind."

In Olympic sailing, individual competitors or teams of athletes sail various classes of sailboats in timed trials over a single course. The contest requires them to navigate upwind, downwind and everything in between. Their final time depends on numerous factors, including the boat design, the skill of the sailors, course difficulty and ocean currents. Perhaps the most important factor, though, is how well the athletes can harness the wind that fills their sails.

Because wind constantly changes speed and direction, athletes and coaches hope to have the best information at the start of a run. On cloudy, rainy days, the standard meteorological tool of Doppler radar can accurately provide wind field information. When no clouds are present, however, Doppler radar is ineffective. The best wind data on clear days comes from ocean buoys and land stations that use wind cups and ultrasonic anemometers to measure wind speed.

In the Qingdao sailing area, where this summer's competitions will take place, only four buoys, one boat and one tower are available to measure sea surface winds within a competition area of approximately 10 square kilometers.

Liu and his lidar group, composed of research scientists and graduate students, have been working with an optical remote sensing technology called Doppler lidar, which they are applying for weather and environmental research. Lidar works by scattering laser beams off atmospheric aerosols or molecules. Doppler lidar takes advantage of the fact that when these aerosols or molecules are moving in the wind, the scattered laser light changes frequency -- the same way an approaching car has a higher pitched sound than a car driving away.

The advantage of Doppler lidar, says Liu, is that it can quickly sample a large area, providing a much finer map of winds than buoys alone. He and his group have developed a lidar bus, which can move equipment to the experiment field conveniently.

Last year, they successfully tested their new bus at the 2007 Qingdao International Regatta sailing event. They moved the bus to the seashore near the sailing field, and made a horizontal scan over the sea surface, making the measurement in real time and then uploading the data to the local meteorological station every 10 minutes. They envision a similar effort in the upcoming Olympic and Paralympic games.

The research was funded by the National Natural Science Foundation of China, the Key Laboratory of Ocean Remote Sensing, the Ministry of Education of China and the China Meteorological Administration (CMA).

WEATHER NOTE

U.S. Department of Labor Giving $17 Million to Iowa to Aid Recovery From Flooding and Tornadoes

WASHINGTON, June 18 /PRNewswire-USNewswire/ -- The U.S. Department of Labor today announced a $17,127,000 grant to create approximately 600 temporary jobs for eligible dislocated workers in Iowa to assist in the cleanup and recovery resulting from damage caused by recent flooding and tornadoes.

"Our hearts go out to Iowans who are suffering from the ongoing flooding and who were victims of the recent tornadoes, including last week's tragic loss of life at a Boy Scout camp," said Secretary of Labor Elaine L. Chao. "This $17 million grant will pay for temporary jobs to aid in the cleanup and recovery from these natural disasters and will provide humanitarian assistance to Iowans in need."

The Federal Emergency Management Agency has declared multiple counties across Iowa as eligible for its Public Assistance Program.

The grant, awarded to the Iowa Workforce Development agency, will provide funding to create temporary jobs to assist in cleanup, demolition, repair, renovation and reconstruction of destroyed public structures, facilities and lands within the affected communities. Funds will also be used for projects that provide food, clothing, shelter, and other types of humanitarian assistance for disaster victims, including work on the homes of individuals who are eligible for the federally funded weatherization program.

Of the total announced today, $6,000,000 will be released initially, with the balance expected to be released on or around June 30.

National Emergency Grants are part of the secretary of labor's discretionary fund and are awarded based on a state's ability to meet specific guidelines. For more information on National Emergency Grants, visit www.doleta.gov/NEG.

U.S. Department of Labor releases are accessible on the Internet at www.dol.gov. The information in this news release will be made available in alternate format (large print, Braille, audio tape or disc) from the COAST office upon request. Please specify which news release when placing your request at 202-693-7828 or TTY 202-693-7755. The Labor Department is committed to providing America's employers and employees with easy access to understandable information on how to comply with its laws and regulations. For more information, please visit www.dol.gov/compliance.

Source: U.S. Department of Labor

Volunteer Agencies Play Key Role In Wisconsin Disaster Recovery

Release Date: June 28, 2008
Release Number: 1768-036

» More Information on Wisconsin Severe Storms, Tornadoes, and Flooding

MADISON, Wis. -- Wisconsin residents who suffered losses from the recent severe storms, tornadoes and flooding and continue to have unmet needs may seek help through a number of volunteer groups.

"We would like to encourage Wisconsin residents to take advantage of our 2-1-1 Program when looking for additional assistance," said Wisconsin Emergency Management (WEM) Administrator Johnnie Smith. "It's a valuable resource that unites those who want to help with those who most need assistance."

Residents can dial 2-1-1 on their telephones to obtain information on local volunteer agencies working in their county. The 2-1-1 operators have phone numbers, program and services information, locations, hours of operation and other relevant resources. Those who call 2-1-1 may be referred to resources including housing assistance, counseling services, employment opportunities and health services.

"The volunteer groups are vital elements in all state and federal recovery efforts as they focus on helping families develop effective recovery plans," said Federal Coordinating Officer Dolph Diemont of the Federal Emergency Management Agency (FEMA). As federal coordinating officer, Diemont directs the federal side of the federal/state disaster response and recovery efforts in Wisconsin.

Anyone affected by the recent storms and flooding should register with FEMA by calling 1-800-621-FEMA (3362) or TTY 1-800-462-7585. Wisconsin residents can also register online at www.fema.gov/.

For individuals seeking more information and/or possible participation, here are two volunteer groups currently working in Wisconsin:

Salvation Army
1-800-264-6412 / www.salvationarmywi.org

American Red Cross
1-866-GET-INFO (1-866-438-4636) / www.redcross.org

FEMA coordinates the federal government's role in preparing for, preventing, mitigating the effects of, responding to, and recovering from all domestic disasters, whether natural or man-made, including acts of terror.

MARITIME NOTE

HOT FROM gCAPTAIN.....

This is a problem for all blue water mariners. My contacts tell me that this downgrade is due to special interest such as "private weather services" who want NOAA out of the business of supplying public "open source" weather data. It looks like someone is lobbying someone on the Hill or at NOAA for these changes...

All mariners need to take notice and write david.feit@noaa.gov and let him know that we need this "public service" unchanged!

NOAA To Make Surface Chart Cutback

July 8th, 2008

NOAA Surface Chart Notice" height="320" width="501">

The above shows a notice box on NOAA’s current 24hr Surface Prediction Chart which can be found HERE. It states:

On 08/15/08 the limits of this chart will change to 24N-48N, 48W-101W. Send comments to David.Feit@noaa.gov by 07/15/08

Notice on the live version of this chart Hurricane Bertha and the area of low pressure to her Northeast are both outside the proposed limits! Here at gCaptain we consider this a degradation of service not a simple adjustment of scale and are supprised by this move from an otherwise rational government organization. It is our opinion that the boundries of this chart should instead be increased to cover the entire North Atlantic which would bring it inline with NOAA’s 48 and 96 hour prediction charts (view all charts HERE)!

Please leave your comments regarding this change bleow and we will be sure they get fowarded on to Mr. Feit and our contacts at NOAA. READ>

USCG Safety Alert: Controllable Pitch Propeller Systems and Situational Awareness

Coast Guard strongly recommends that owners, operators, and masters of vessels with controllable pitch propellers understand the design and operation of the system after marine casualty in March of 2008 involving a fishing vessel in the Bering Sea resulted in multiple fatalities and complete loss of the vessel.

July 2, 2008 (Washington, DC): A marine casualty in March of 2008 involving a fishing vessel in the Bering Sea resulted in multiple fatalities and complete loss of the vessel. A Marine Board of Investigation is currently examining the various circumstances surrounding the casualty. Although the investigation is not complete, safety issues associated with casualty have been identified that merit immediate public dissemination.

Based on the survivors' testimony, the crew experienced difficulty with launching and entering the three liferafts because the vessel was making considerable sternway when the order to abandon ship was issued. Evidence indicates the main engines were still running and the vessel was backing with significant astern pitch. Consequently, two of the liferafts quickly traveled forward past the bow of the vessel when they were launched. Attempts to retrieve the liferafts using the painter lines were unsuccessful. As a result, the majority of the crew members were forced to jump into the 34°F water and attempt to swim to the liferafts. Ultimately, only 22 members of the vessel's crew made it into the liferafts. All of these crew members survived. Of the other 25 crew members who never made it into a liferaft, four died and one remains missing.

The Coast Guard strongly recommends that owners, operators, and masters of vessels with controllable pitch propellers understand the design and operation of the system. This includes the primary and emergency sources of power for both the control and main systems, the location and procedures for using alternate control stations, and the locations of the emergency shutdowns. While controllable pitch propeller systems are generally designed and constructed to fail in the "as is" position, in hydraulic CPP systems, the actual blade pitch may change. In this case the vessel was making considerable sternway. This was not a unique occurrence. The MS EXPLORER also experienced this problem before it sank in November of 2007. Vessel operators, masters and crew members must be prepared to respond accordingly.

In light of this incident, vessel owners, operators, masters and crew members should also be mindful of the following safety issues:

1. Vessel masters and officers must maintain situational awareness at all times and understand the effects of their actions and decisions on the safety of their crew, especially during emergency situations involving flooding. This includes understanding what impact the vessel's speed, heading, heel, and trim will have on the crew as it abandons ship.

2. The master or individual in charge must evaluate the particular circumstances of each emergency situation (weather, seas, experience of crew, condition of vessel, etc.) and adjust emergency procedures accordingly to provide for the safety of his crew, vessel, and the environment.

3. All crew members should understand that immersion suits will affect their dexterity, limit mobility, and may make it more difficult to launch survival craft, particularly when the survival craft are covered with snow or ice. Crew members responsible for launching the survival craft should practice and be able to do so with their immersion suits on. Lifesaving gear should be kept free of ice and snow whenever possible.

4. When abandoning ship, crewmembers should make every effort to enter directly into a liferaft or lifeboat before entering the water. If crewmembers must enter the water, they should stay together and attempt to enter a liferaft, climb onto floating debris, or use any other means available to get themselves out of the water as soon as possible.

5. Emergency Drills should not be limited to routine procedures such as donning immersion suits. Emergency drills should ensure all crew members, including bridge and engine room personnel, understand and practice what to do in various emergency situations under actual conditions.

Additional information regarding emergency procedures for Commercial Fishing Vessels can be found at: http://www.fishsafe.info.

This safety alert is provided for informational purpose only and does not relieve any domestic or international safety, operational or material requirement. Developed and distributed by the Office of Investigations and Analysis, United States Coast Guard Headquarters, Washington, DC.

RS

Gravity Waves Make Tornados

Gravity Waves Make Tornadoes

+ Play Audio | + Download Audio |

March 19, 2008: Did you know that there's a new breakfast food that helps meteorologists predict severe storms? Down South they call it "GrITs."

GrITs stands for Gravity wave Interactions with Tornadoes. "It's a computer model I developed to study how atmospheric gravity waves interact with severe storms," says research meteorologist Tim Coleman of the National Space Science and Technology Center in Huntsville, Alabama.

According to Coleman, wave-storm interactions are very important. If a gravity wave hits a rotating thunderstorm, it can sometimes spin that storm up into a tornado.

Above: Click on the image to watch a gravity wave roll over Tama, Iowa, on May 7, 2006. Credit: Iowa Environmental Mesonet Webcam.

What is an atmospheric gravity wave? Coleman explains: "They are similar to waves on the surface of the ocean, but they roll through the air instead of the water. Gravity is what keeps them going. If you push water up and then it plops back down, it creates waves. It's the same with air."

Coleman left his job as a TV weather anchor in Birmingham to work on his Ph.D. in Atmospheric Science at the University of Alabama in Huntsville. "I'm having fun," he says, but his smile and enthusiasm already gave that away.

"You can see gravity waves everywhere," he continues. "When I drove in to work this morning, I saw some waves in the clouds. I even think about wave dynamics on the water when I go fishing now."

Gravity waves get started when an impulse disturbs the atmosphere. An impulse could be, for instance, a wind shear, a thunderstorm updraft, or a sudden change in the jet stream. Gravity waves go billowing out from these disturbances like ripples around a rock thrown in a pond.

When a gravity wave bears down on a rotating thunderstorm, it compresses the storm. This, in turn, causes the storm to spin faster. To understand why, Coleman describes an ice skater spinning with her arms held straight out. "Her spin increases when she pulls her arms inward." Ditto for spinning storms: When they are compressed by gravity waves, they spin faster to conserve angular momentum.

"There is also wind shear in a gravity wave, and the storm can take that wind shear and tilt it and make even more spin. All of these factors may increase storm rotation, making it more powerful and more likely to produce a tornado."

"We've also seen at least one case of a tornado already on the ground (in Birmingham, Alabama, on April 8, 1998) which may have become more intense as it interacted with a gravity wave."

Above: Click on the graphic to play an actual Doppler radar movie of a gravity wave interacting with a rotating thunderstorm and making it stronger in northwest Alabama on Jan. 22, 1999. Credit: NOAA.

Coleman also points out that gravity waves sometimes come in sets, and with each passing wave, sometimes the tornado or rotating storm will grow stronger.

Tim and his boss, Dr. Kevin Knupp, are beginning the process of training National Weather Service and TV meteorologists to look for gravity waves in real-time, and to use the theories behind the GrITs model to modify forecasts accordingly.

Who would have thought grits could predict bad weather? "Just us meteorologists in Alabama," laughs Coleman. Seriously, though, Gravity wave Interactions with Tornadoes could be the next big thing in severe storm forecasting.

Weather Notes

Spring Yields Tame To Tempest

The long awaited spring will arrive none too soon. With it comes more tolerable temperatures and those flower sprouting showers you hear songs about. But the core of this season’s rain activity isn’t portrayed as gentle showers as much as in pounding thunderstorms. The contrast in temperature between the receding grip of winter and summer’s northward advance will determine their intensity. Storms can vary from a distant annoyance to a raging overhead fury. Your best defense is to hope for the best while preparing for the worst. Your first line of defense when threatening weather approaches is not to panic. Cooler heads prevail. Should you hear sirens alerting you of impending danger, or you personally see damage occurring from advancing storms, seek shelter along the wall of your basement. If you have no basement, retreat to a central first floor room with no outside walls. This could be a bathroom or closet.

Let’s prepare even further ahead. While the weather is placid, make a plan now for where you will go when the worst occurs. Should your home become unlivable after an event, you will need a money resource and ID to hold out until your home is restored. To avoid these things being lost in the storm, prepare now what you will collect enroute to your shelter. Know where these items are at all times so you don’t spend precious time looking for them. Keep a bag or satchel at the ready to collect them on the run. Some of these items should include any cash, your checkbook, charge cards, driver’s license, and your car keys in case your vehicle survives. This is your survival kit, the seed to putting your life back together.

The National Weather Service classifies “severe” thunderstorms as producing ¾ inch diameter hail or greater, strong wind downbursts of 58 mph or more, or a storm producing a tornado. National outlooks for the probability of severe storms will be issued days ahead of time with suspected trouble areas covering whole regions of the country. Severe Thunderstorm and Tornado Watches are usually issued hours before storms appear or blossom into severe stage and may cover several states. If you are included in a Watch area, this is a good time to gather your valuables or take note of where they are. Watches are in effect for many hours and are not specific when or where any one location will experience severe thunderstorms.

Warnings are issued when a severe thunderstorm or tornado has been reported or determined by local radar to be imminent. A warning will be cause for local authorities to sound the sirens for your area. These are issued for a period of an hour or less, covering parts of an individual county. A Severe Thunderstorm Warning implies the large hail and/or high winds, as defined above, with the possibilities of tornadoes. A Tornado Warning implies specifically that a tornado has been spotted in or near your area.

While most receive their alerts via siren or the television crawl, the quickest reception will be through NOAA weather radio. Technology has come a long way since the old weather band radios. You can now purchase crystal controlled weather alert radios from a local electronics store. These modern day weather radios can be programmed to a local frequency to alert you of any warnings issued in or near your community. In non-threatening weather, you can use them to keep abreast of current weather conditions and forecasts, commercial-free. Warnings will interrupt the regular forecasts within seconds of their issuance from the National Weather Service. And the faster you are aware of the danger, the more time you have to take cover.

Keeping food safe during an emergency

March 20, 2008

The U.S. Department of Agriculture is providing recommendations to the regions affected by severe weather and flooding in the Central United States. USDA is hopeful that this information will help minimize the potential for foodborne illnesses due to food spoilage from power outages and other problems that are often associated with severe weather events.

“Power outages can occur at any time of the year and it often takes from a few hours to several days for electricity to be restored to residential areas,” said USDA Under Secretary for Food Safety Dr. Richard Raymond. “Without electricity or a cold source, foods stored in refrigerators and freezers can become unsafe. Bacteria in food grow rapidly at temperatures between 40 and 140 °F, and if these foods are consumed, people can become very sick.”

Steps to follow to prepare for a possible weather emergency:

• Keep an appliance thermometer in the refrigerator and freezer. An appliance thermometer will indicate the temperature in the refrigerator and freezer in case of a power outage and help determine the safety of the food.
• Make sure the freezer is at 0 °F or below and the refrigerator is at 40 °F or below.
• Freeze containers of water for ice to help keep food cold in the freezer, refrigerator or coolers after the power is out.
• Freeze refrigerated items such as leftovers, milk and fresh meat and poultry that you may not need immediately — this helps keep them at a safe temperature longer.
• Plan ahead and know where dry ice and block ice can be purchased.
• Store food on shelves that will be safely out of the way of contaminated water in case of flooding.
• Have coolers on hand to keep refrigerator food cold if the power will be out for more than 4 hours. Purchase or make ice cubes and store in the freezer for use in the refrigerator or in a cooler. Freeze gel packs ahead of time for use in coolers.
• Group food together in the freezer - this helps the food stay cold longer.

Steps to follow after the weather emergency:

• Keep the refrigerator and freezer doors closed as much as possible to maintain the cold temperature.
• The refrigerator will keep food safely cold for about 4 hours if it is unopened. A full freezer will hold the temperature for approximately 48 hours (24 hours if it is half full) and the door remains closed.
• Discard refrigerated perishable food such as meat, poultry, fish, soft cheeses, milk, eggs, leftovers and deli items after 4 hours without power.
• Food may be safely refrozen if it still contains ice crystals or is at 40 °F or below when checked with a food thermometer.
• Never taste a food to determine its safety!
• Obtain dry or block ice to keep your refrigerator and freezer as cold as possible if the power is going to be out for a prolonged period of time. Fifty pounds of dry ice should hold an 18-cubic-foot full freezer for 2 days.
• If the power has been out for several days, check the temperature of the freezer with an appliance thermometer. If the appliance thermometer reads 40 °F or below, the food is safe to refreeze.
• If a thermometer has not been kept in the freezer, check each package of food to determine its safety. If the food still contains ice crystals, the food is safe.
• Drink only bottled water if flooding has occurred.
• Discard any food that is not in a waterproof container if there is any chance that it has come into contact with flood water. Discard wooden cutting boards, plastic utensils, baby bottle nipples and pacifiers.
• Undamaged, commercially prepared foods in all-metal cans and retort pouches (for example, flexible, shelf-stable juice or seafood pouches) can be saved. Follow the Steps to Salvage All-Metal Cans and Retort Pouches.
• Thoroughly wash all metal pans, ceramic dishes and utensils that came in contact with flood water with hot soapy water and sanitize by boiling them in clean water or by immersing them for 15 minutes in a solution of 1 tablespoon of unscented, liquid chlorine bleach per gallon of drinking water.
• When in Doubt, Throw it Out!

Asia: Satellites Help Manage Disasters

United Nations, Mar 20 (Prensa Latina) The UN Economic and Social Commission for Asia and the Pacific (ESCAP) calls to use satellites to predict and manage natural disasters in Asia.

Asia-Pacific have endured six of the worst natural disasters of the decades so the experts consider that an effective data collection from satellites may be effectively used for such end.

ESCAP said Disaster Management is the topic at a 72-hour seminar opened Wednesday in Bangkok, Thailand, with officials from 22 countries of Asia, host of 21,000 disaster victims in 2006, three fourth such events in the world.

Of the 53 member states of ESCAP, eight are among the 10 most affected by such natural calamities.

The specialists define as adequate disaster management an effective use of data supplied in time to assess risks, mitigate the impact, monitor the phenomena and issue early warning.

Shigeru Mochida, executive vice president of ESCAP, added that satellites may play a relevant role in rescue and assistance.

MARITIME NOTES

DNV “CASUALTIES TWICE AS LIKELY AS 5 YEARS AGO”

Thursday, 21 February 2008

NORWEGIAN classification society DNV says the chances of a ship being involved in a serious casualty have doubled in five years. DNV, which monitors the annual frequency of serious accidents, says that over the past five years, there has been an increasing incidence of serious navigational accidents in several shipping segments.

Speaking at DNV seminar in Singapore yesterday. Helge Kjeøy, regional manager DNV Maritime South East Asia said: “The main factors explaining the negative developments over the past few years are - that the undersupply of crew worldwide results in reduced experience and that the high commercial pressure results in a high workload. Adding new and more complex equipment does not only help the situation. Avoiding accidents under such situations requires a good safety culture, something which the maritime industry evidently needs to focus more on.”

Torkel Soma, Principal Safety Consultant in DNV Maritime, said: “DNV’s statistics shows that a ship is twice as likely to be involved in a serious grounding, collision or contact accident today compared to only five years ago. In addition, estimates show that also the costs of these accidents have doubled. Since this is the general trend for the international commercial fleet, the maritime industry needs to act on this immediately.”

The boom in the shipping market and increased deliveries of newbuildings has resulted in pressure on crews. The shortage of officers has resulted in lower retention and faster promotion. As a result, the general level of experience is decreasing on board. At the same time new technical solutions have been introduced which might have increased the complexity of operations.

Dr. Soma pinpoint: “Reliable technology and complying manuals are no assurance against making errors. Collisions, groundings and contact accidents do almost always involve human acts.”

Ferry Riverdance decision due next week
By Lisa Ettridge

A DECISION on the future of stranded ferry Riverdance has been deferred again as coastguards say more information is needed.

It was hoped the fate of the stricken ship could be made at a meeting today but now discussions will not be taking place until next week. A spokesman for the Marine and Coastguard Agency said: "No decision about Riverdance is going to be made until next week at the earliest. "We had hoped the future of the vessel could be decided this week but we are still exploring our options at this stage. "We need to gather more information so we can make a properly informed choice and all parties concerned will meet probably in the middle of next week." Companies who lost property aboard the stranded ferry are cutting their losses one businessman said today. Steve Slater of SJ Slater Transport which is based in Cockerham, near Lancaster says he does not believe he will get his trailer back. He said: "I suppose what has happened to Riverdance is just one of those things, there is nothing that can be done about it."

Messing About In Ships Podcast Episode # 16

March 21, 2008, 4:27 am
Filed under: Uncategorized | Tags: daily source code, lloyds list, london bridge, mais, maritime, merchant marine, podcast, queen of the north, severe weather, ships, twitter

Messing About In Ships podcast episode #16 has launched.

(54 minutes)

Download MP3 file: Messing About In Ships 16

Subscribe Via iTunes HERE

Spring has sprung, the grass has riz, wonder where all the flowers is?

HAPPY EASTER TO ALL!
Seafarers Prayers





RS

Sea alarms set

Sea alarms set

The final two buoys for a tsunami alert network are deployed

By Gary T. Kubota

WAILUKU » The final two tsunami detection buoys for the Pacific warning network were deployed this week, completing a system of sensors begun after the 2004 Indian Ocean disaster that killed hundreds of thousands of people.

Scientists say the new system will show whether an earthquake has generated a deep-ocean wave, reducing the chances of an unnecessary evacuation in Hawaii and increasing detection coverage in places such as the western Pacific and South America.

"It means that basically our uncertainties about tsunamis from tricky places have pretty much been removed," said Gerard Fryer, a geophysicist for the Pacific Tsunami Warning Center in Ewa Beach. "Right now, as far as Hawaii is concerned, we no longer have any blind spots, and let me tell you it's a wonderful feeling."

The final two buoys were deployed off the Solomon Islands, about 111 miles northeast of Australia. The network has 39 stations in the Pacific, Atlantic, Caribbean and Gulf of Mexico.

Fryer said that before 2004 there were six tsunami detection buoys, four of them in the Pacific and two not working.

He said scientists continue to monitor the magnitude of earthquakes and potential tsunamis through a network of seismometers.

---

Before the development of buoy technology, scientists measured wave changes through tidal gauges along coastlines.

Buoys that record wave pressure at the bottom of the ocean have enabled scientists to be more accurate in their predictions, Fryer said. Unlike surface waves generated by wind, tsunamis reach all the way to the bottom of the ocean.

The latest deep-ocean buoys, which are more reliable and cost about half as much as ones made several years ago, are able to receive wave information through low-energy sound from seabed sensors. Information is transmitted from the buoy to a constellation of earth-circling satellites.

While the northern Pacific Rim is known for frequent earthquakes, South America was the source of a tsunami in 1960 that killed 61 people in Hilo.

The magnitude of the earthquake in Chile was so large it went off the scientific measuring scale at the time and was thought initially to be magnitude 8.5, Fryer said.

Fryer said scientists took 10 years to determine that the earthquake in Chile was a 9.5.

"It was far bigger than anybody understood," he said.

Fryer said to make matters worse, an earthquake of 8.4 had generated waves of a few inches the day before the tragedy, so people "thought it was no big deal."

"We have much better instruments now," he said. "We understand the process much better."

The U.S. Tsunami Warning System is operated by the National Oceanic and Atmospheric Administration, which also oversees the Pacific Tsunami Warning Center. The agency, part of the Department of Commerce, is also working with 70 countries and the European Commission to develop an integrated global monitoring network.

FROM HOLLAND AND KNIGHT

NOAA – US tsunami warning system completed The National Oceanic and Atmospheric Administration (NOAA) issued a news release stating that, with the recent deployment of two tsunami detection buoys in the South Pacific, the US tsunami warning system has been completed. (3/10/08).

WEATHER NOTES

Ice "Bergs" on Lake Michigan

The relatively warmer temperatures and sunshine of the last several days have caused areas of ice that had been affixed to the western shore of Lake Michigan off the Racine and Kenosha areas to break away from the shore. The blustery west winds on Tuesday have carried these floating ice "bergs" several miles away from shore.

Here is a high resolution MODIS visible satellite image from 102 pm CDT from March 10th.

It shows the ice remaining along the shore from Milwaukee south to Racine, Kenosha and the Illinois State Line.

---

What a difference a day makes! Here is a high resolution satellite image from Tuesday taken at 144 pm CDT.

The warmer temperatures, sunshine and brisk west winds have caused the ice to break away from shore and float several miles away from shore. The above freezing temperatures expected the next several days should cause these floating ice "bergs" to shrink and disappear.

Marc Kavinsky - Senior Forecaster/Meteorologist

Being prepared

Published 3/12/2008

By EMILY BEHLMANN

ebehlmann@gctelegram.com

Coming off of what the National Weather Service calls a record-breaking year for tornadoes in Kansas -- a total of 137 occurred in 2007, killing 14 people and injuring 82 -- several agencies are working to educate Kansans this week about severe weather preparedness.

The National Weather Service, the Kansas Emergency Management Association and the Department of Emergency Management have declared this week as Kansas Severe Weather Awareness Week.

Locally, efforts have included awareness and storm-spotter training sessions on Monday and a tornado siren test and statewide drill on Tuesday, according to Cathy Hernandez, Finney County Emergency Management coordinator.

The National Weather Service states that severe weather can threaten Kansans all year long, and Jamie Bielinski, a weather service meteorologist based in Dodge City, said residents need to realize that severe weather like tornadoes can strike anytime.

However, she said, the season that statistically sees the most tornadoes is approaching, generally running from April through June.

Tornadoes aren't the only severe-weather threat. In 2007, several severe thunderstorms, with hail and high winds, caused millions of dollars in damage to property and crops.

One came to Finney County on Aug. 20, with gusts killing a woman at Meadow Lake Park and causing damage at places including Holcomb High School, Sunflower Electric Power Corp., Peterbilt and Labrador Apartments.

The National Weather Service also warns Kansans that they should be prepared for weather like flooding and what a weather service guide calls "the underrated killer" -- lightning.

Hernandez said Finney County Emergency Management takes steps to ensure severe-weather readiness, like training storm spotters and maintaining relationships with ham radio operators who assist personnel in emergencies.

During severe weather, county public works employees serve as storm spotters and traditional first responders -- firefighters, police officers, sheriff's deputies and Emergency Medical Services employees -- go out in force to handle problems, she said.

To help avoid problems in the first place, Hernandez said her department is pushing public education through means like a Citizen Emergency Preparedness Guide. The guide is available in the Emergency Management office at the Law Enforcement Center, and it soon will be distributed throughout the community.

Hernandez and Carolyn Henry, director of Garden City's chapter of the American Red Cross, stress awareness and preparedness on an individual basis, and by businesses and organizations, as the best ways to avoid harm during severe weather. The first step is to realize when there is a risk of severe weather by paying attention to watches and warnings. A "watch" means that conditions are favorable for severe weather, and it should prompt people to keep abreast of the weather for the day, Bielinski said. A "warning" means the threat is imminent.

"If they hear a warning, they need to immediately take shelter," she said.

Tornado warnings are sounded with outdoor sirens, but Bielinski said it's usually hard to hear them indoors. That's why she recommends keeping up with television or radio reports, and using an All Hazards NOAA weather radio.

"A weather radio is basically like having a tornado siren in your home," she said.

When severe weather does strike, Henry said, it's essential to already have a disaster plan in place.

"If they're aware of what you need to do, they're not going to panic," she said. "They will not go through the stress of 'What should we do? Where should we go?'"

For a family, that plan should include two places to meet following disaster: one location right outside the home in case of a sudden emergency, like a fire, and one location outside the neighborhood in case the area is evacuated.

A plan also should include two out-of-town contacts reachable by each family member.

Henry also emphasized the need to keep a kit with a three-day supply of essential items, including important paperwork and some cash. Even if someone uses a Red Cross shelter, the agency won't be able to attend to all needs immediately, she said.

More information about severe weather preparedness is available at the Web sites for the National Weather Service in Dodge City at www.weather.gov/ddc and the U.S. Department of Homeland Security's Ready Campaign, www.ready.gov.

MARITIME NOTES

MAIB publishes report of FR8 VENTURE tragedy in Pentland Firth
Report into incident on tanker on 11th November 2006 which resulted in fatalities.

At about 1220 on 11 November 2006, while outbound from Scapa Flow and transiting the Pentland Firth, the 74,065 dwt Singaporean registered tanker, FR8 VENTURE, shipped two large waves over her bow. This resulted in the death of two able seamen (ABs) and serious injuries to an ordinary seaman (OS), all of whom were working on the forward mooring deck. The waves also caused minor damage to the ship.

From 10 to 11 November, FR8 VENTURE carried out a ship-to-ship transfer with another tanker, Perseverance, while at anchor in Scapa Flow, and loaded a full cargo of crude oil. The loading operations were completed at 0536, and Perseverance let go from FR8 VENTURE and left Scapa Flow. FR8 VENTURE weighed anchor at about 1054 and the two pilots disembarked near the entrance to Scapa Flow at about 1136. The wind was west to west-north-west and near gale force, with waves of about 4 to 5m high. The ship’s freeboard was about 6.6m and spray was being shipped on board. The tidal stream was flowing generally in the same direction as the wind. (report continued)


RS

Understanding & predicting severe storms

Understanding & predicting severe storms

According to the Department of Commerce, 42 percent of our gross domestic product is in sectors that are affected by severe weather and climate. Bad weather, or badly forecast weather, means far more than cancelled plans and personal inconvenience. The impact of the weather on our economy, safety, and environment can be severe both through extreme events (hurricanes, tornadoes, floods, drought, etc.) and just day-to-day fluctuations. In the U.S., estimates of average annual damage ($16 billion) and loss of life (1,500) are significant and impact every state. According to the Department of Commerce, 42 percent of our gross domestic product is in sectors that are affected by severe weather and climate. Conversely, good information about weather and climate can be used effectively to enhance economic activities and improve quality of life.

Researchers in NCAR's Mesoscale and Microscale Meteorology Division of the Earth and Sun Systems Laboratory, and in the Research Applications Laboratory, strive to understand the physical processes and genesis of such extreme weather, in order to protect human lives and property.

Studying Severe Storms

• Thunderstorms

  More than 1,000 thunderstorms rage across Earth's surface at any moment. They bring beneficial rains, but thunderstorms can also spawn lightning, tornadoes, hail, and flash floods. NCAR scientists and their collaborators pry into the heart of thunderstorms using aircraft, balloons, mobile radars, and computer models.

• Hail

  The pelting chunks of ice known as hail can ruin vehicles and slice plants to ribbons in minutes. Only a few Americans have been killed by hail in recent decades, but a number are injured each year. NCAR researchers have analyzed some of the biggest hailstones on Earth and developed radar-based techniques for spotting hail.

• Lightning

  Using sophisticated instruments that can track lightning bolts and the electric fields that trigger them, NCAR scientists have learned much about these spectacular, deadly products of thunderstorms.

• Tornadoes

  More than 1,000 twisters touch down in the United States in a typical year. However, U.S. death and injury tolls have dropped considerably in recent decades due to better warnings. NCAR has joined colleagues to delve into the processes that drive tornado formation and evolution.

• Floods

  The powerful and deadly force of flash floods is an underrated risk. Even though the U.S. population has nearly doubled since 1950, the death toll from most weather hazards has dropped by half or more, while the flooding toll has risen slightly. NCAR's precipitation research touches on many aspects of the flood threat.

• Hurricanes and Typhoons

  Tropical cyclones with winds at or above 74 miles per hour (119 kilometers per hour) are called hurricanes in the Atlantic and northeast Pacific, and typhoons in the western Pacific. Sensors and computer models developed at NCAR help track and predict these tropical tempests more accurately than ever.

• Winter Storms

  Large, complex weather systems can dump snow on one city, coat another with ice, and drench others in rain. These storms are shaped by weather elements that extend from the tropics to the poles and from ground level to the heights where aircraft cruise. NCAR is studying the mechanisms behind our worst winter storms.

WEATHER NOTES

The First Tornado Forecast

March 9, 2008, 10:06 pm | Bill Murray | Weather History

Before a man in the Signal Corps named John Park Finley came along, the tornadoes that occurred on the American Plains were considered to be unforecastable. Finley was allowed to investigate the destructive storms by his superiors. He was assigned to the Weather Research Unit in Washington, D.C.

Finley had studied the atmospheric parameters that were present during previous tornadoes. In 1884, he published his research in the journal Science. Here are those parameters, published in a 1999 Weather & Forecasting article.

1. there is a definite relation between the position of tornado regions and the region of high contrasts in temperature, the former lying to the south and east;

2. there is a similar definite relation of position of tornado regions and the region of high contrasts in dewpoint, the former being, as before, to the south and east;

3. the position of tornado regions is to the south and east of the region of high contrasts of cool northerly and warm southerly winds—a rule that seems to follow from the preceding and is of use when observations of temperature and dewpoint are not accessible;

4. the relation of tornado regions to the movement of upper and lower clouds has been studied and good results are still hoped for;

5. the study of the relation of tornado regions to the form of barometric depressions seems to show that tornadoes are more frequent when the major axis of the barometric troughs trends north and south, or northeast and southwest, than when it trends east and west.

On this date (March 10) in 1884, Finley issued the first experimental tornado prediction, utilizing the parameters. As you can see, they are still accurate and largely in use today. The use of the word “tornado” in forecasts would be banned a few years later. That ban would remain in place until 1952.

MARITIME NOTES

High winds fail to halt Riverdance ferry bid
By Rob Stocks

STRONG winds and high tides will not hamper efforts to salvage the stricken ferry Riverdance. It is now more than five weeks since the 6,000-ton roll on roll of ferry ran aground on the sands at Anchorshome after being struck by a freak wave in the Irish Sea.

See more information on The Riverdance

Hopes are high she can be returned to an upright position this week, despite nightmare weather being predicted today.

View our Shipwreck online special

See The Riverdance webcam

See our Riverdance picture gallery - updated daily

There are severe weather warnings for some parts of the west coast today coupled with a spring tide in excess of nine metres.

But officials from the Coastguard Agency believe they will not cause any worsening in the Riverdance's 90 degree list.

Flotation tanks are now clearly visible on one side of the ferry.

A spokeswoman said: "We are keeping a close eye on the situation at Blackpool.

"Obviously there are going to be some high tides and strong winds.

"We do not however believe that will pose any further problems for the Riverdance. She should not move any further.

"The timetable is still in place for attempts to bring her upright on Thursday."

Despite some reports the Riverdance would be cut up on the sands at Anchorsholme, coastguards and salvage team members are still hopeful she can be towed off in one piece.

A spokeswoman for the coastguard said: "Work on the salvage efforts in going well.

"All the welding onboard is complete.

"It is still the plan to tow her off the sands and the salvage team are confident that can happen."

Met Office officials are expecting the worst of the storms to miss Blackpool, but predict a 20 per cent chance of disruption in North West England as a result of the weather.

People are being urged to stay away from the sea front as strong winds coupled with a high tide could make the area dangerous.

The winds are due to ease across the UK by early on Tuesday.

RS

THETA-E: The Un-used Parameter

A while back storm spotters and chasers had a discussion on the Theta-E Parameter.

Ok so what is the Theta-E and why is it used?

Meteorologist Jeff Haby explains.

1. What is THETA-E?

THETA-E (Equivalent Potential Temperature) is the temperature that results after all latent heat is released in a parcel of air and the then brought adiabatically to the 1000 mb level. THETA-E increases as dewpoint


2. How is THETA-E determined?

First determine the pressure level of interest. Locate the temperature and dewpoint at that pressure level. Raise that parcel adiabatically from that pressure level to the 200-mb level. Next, bring the parcel down dry adiabatically to the 1000 mb level. The temperature once the parcel is at 1000 mb is the THETA-E.

3. Operational significance of THETA-E:

INSTABILITY- A region with a relatively high THETA-E is often the region with the most instability. Warmer low level temperatures and higher low level dewpoints increase instability.

LOW LEVEL JET- A low level jet from a moisture source will often bring in higher THETA-E values and thus increased instability.

THETA-E RIDGE- These are regions with higher THETA-E. They are often the burst point for convective activity.

4. Pitfalls:

a. If a strong cap is in place, convective storms will not occur even if THETA-E is high.

What does this mean to Storm Chasers? Storm Chaser Steve Sponsler explains...

"THETA-E: The Un-used Parameter

Have you ever wondered where a true frontal boundary or the dry-line exists? Why ask?

When it comes to chasing...you have to know these factors along with many others...but this discussion is focused only on Theta-E for discussions sake:

The Theta-E advection parameter could be a major clue. It combines what surface analysis provides as well as the dewpoint forecast parameter.

It also works in tandem with injecting dry slots...and what I often think of as "pressure points". One must combine these two to "brew" the secret ingredient.

What are "pressure points"? Microscale low pressure areas. Those are areas where micro-scale low pressure areas form, particularly in the Plains...formed mostly from downslope winds off the Rockies ALONG with the Coreollis Force...concurrent with upslope, moist air from the GOM (Gulf of Mexico) and forcing upper level winds from the WNW. SEE IT IN YOUR MIND.

VISUALIZE...and work it...Dry Slots swiping up moisture and being forced to rotate because of the earth's rotation..in reality..it makes perfect sense.

And for chasing purposes...PLAN your road networks in advance.

I surmise that anyone here already does that.

It COULD be a "secret" ingredient to what might overlie all the other parameters provide. But then again...I please hope than no one denies that luck in all cases is involved in a successful chase."

CASE STUDY-1

A relationship between a surface theta-e ridge and dominant lightning polarity

Nettie R. Lake, Lyndon State College, Lyndonville, VT; and D. R. MacGorman

For many years, it was believed that cloud-to-ground lightning lowered only negative charge to the ground (-CG flashes). In the past twenty years, however, flashes lowering positive charge (+CG flashes) have been documented and studied. This presentation summarizes positive correlations between +CG flashes, hail, and tornadoes.

Recent studies have reported that in some cases, dominant storm polarity reverses from positive to negative. Additionally, it has been observed that 50% of such storms are tornadic, and that tornadoes usually occur during or after the reversal. Smith et al. (2000) observed that polarity reversals often occur at surface equivalent potential temperature (theta-e) ridges. This study examined dominant polarity patterns of severe storms during the entire year 1999. Similar to Smith et al. (2000), this study found that 82% of polarity reversals occur at a theta-e ridge.

Furthermore, positively dominated storms that move parallel to a ridge axis seldom reverse polarity. Also, negative storms do not reverse polarity relative to a theta-e ridge. Explanations for why polarity reversals may occur at a theta-e ridge will also be discussed.

Extended Abstract (68K)

CASE STUDY - 2

WMSI - A New Index For Forecasting Wet Microburst Severity

Kenneth L. Pryor and Gary P. Ellrod
Office of Research and Applications (NOAA/NESDIS)
Camp Springs, MD
Date Submitted: November 20, 2003

Abstract

A new index to assess the potential and severity of wet microbursts is currently under development. The index, designated as the Wet Microburst Severity Index (WMSI), accounts for the physical processes of convective storm development and downburst generation by incorporating such parameters as convective available potential energy (CAPE), to represent the process of updraft formation, and Theta-e Deficit (TeD), to represent downburst development.

Since convective storm updrafts require buoyant energy, a very important parameter used in the analysis of convection is CAPE, which is easily computed from Geostationary Operational Environmental Satellite (GOES) sounding data. Since updraft strength is proportional to CAPE, large CAPE would result in strong updrafts that could lift the precipitation core within a convective storm to the mid-level dry air layer. CAPE also plays a major role in the formation of precipitation.

The strong updrafts resulting from large CAPE will increase the size of precipitation particles, which, in turn, will then enhance the effect of precipitation loading. The amount of mid-level water vapor relative to the low-level water vapor in the atmosphere as indicated by a sounding profile is important in the determination of the strength of downdrafts that occur in convective storms. This condition is modeled by the Theta-e Deficit (TeD), represented by the algorithm TeD = theta-e_max - theta-e_min, where (theta-e_max) refers to the maximum value of theta-e at the surface and (theta-e_min) refers to the minimum value of theta-e in the mid-levels of the troposphere.

TeD serves as an important indicator of the difference in water vapor concentration (plus thermal energy cpT) between the surface and mid-levels. Large TeD values imply the presence of relatively dry air at mid levels that will result in evaporative cooling and the generation of large negative buoyancy as the dry air is entrained into the convection cell. The WMSI algorithm is given as the following expression: WMSI = (CAPE)(theta-e_max - theta-e_min)/1000.

CASR STUDY - 3

Midlevel Dry Intrusions as a Factor in Tornado Outbreaks Associated with Landfalling Tropical Cyclones from the Atlantic and Gulf of Mexico.

Lon Curtis
KWTX-TV, Waco, Texas

ABSTRACT

Midlevel dry intrusions have been mentioned as a factor in tornado outbreaks associated with landfalling tropical cyclones for more than three decades, but a systematic analysis of historical outbreak cases with respect to this pattern has been missing.

Herein, following an examination of all named tropical cyclone landfalls from the Atlantic and Gulf of Mexico for the period 1960–99, 13 “outbreak” cases (defined as storms producing 20 or more tornadoes) have been identified with 11 of the cases offering clear evidence of a dry intrusion at midlevels over the outbreak area. The outbreaks all occurred when the favored area for tornadogenesis (the right-front or northeast quadrant of the storm) coincided with a pronounced gradient of relative humidity, with the gradient best reflected at the 700- and/or 500-hPa level(s).

Two distinct patterns were identified with respect to the origin of the midlevel dry air involved in these cases: in one, a mass of dry air that impinged on much of the northern or northwestern semicircle of the storm's outer circulation gradually divided into two separate areas (one to the northwest and the other to the northeast of the storm center) as the storm advanced; the other involved ingestion of a lobe of dry air from a reservoir most often located in the eastern semicircle of the storm.

The outbreak cases were determined to have a strong diurnal signal detected in the temporal distribution of the tornadoes, as almost two-thirds (65%) of the tornadoes in the 11 “positive” cases occurred between 1500 and 2400 UTC (daylight hours in the region examined). A review of all tropical cyclone landfall events since 1960 revealed that there are only three cases with clear evidence of a midlevel dry intrusion that were not accompanied by an outbreak as defined herein.

TORNADO OUTBREAK

30 Twisters in Al, Ga and Fla for 17 February 2008

Meteorologists Study Deadly Tornado Outbreak

Warm moist air and a shifting weather pattern courtesy of the La Nina phenomenon aided in the development of the Feb. 5 tornadoes, which killed at least 50 people and were among the 15th deadliest in U.S. recorded history. But meteorologists are now trying to explain why the tornadoes occurred so early in the year.

It was farther north than most February tornadoes and stronger, Joseph Schaefer, director of the Storm Prediction Center in Norman, Okla., told Associated Press.

Tornadoes do occur in February. In 1971, a deadlier February outbreak in the Mississippi Delta killed 121 people. A study conducted by Schaefer two years ago, found that winter tornadoes in parts of the South occur more frequently and are stronger when there is a La Nina, a cooling of Pacific waters that is the flip side of the better known El Nino.

February tornadoes usually pop up near the Gulf Coast, not in Kentucky or Tennessee, said University of Oklahoma meteorology professor Howard Bluestein.

A heavy contributing factor was the warm weather. It was 84 degrees in Oklahoma before the storm front moved through on its path of destruction. On Tuesday, 97 weather stations broke or tied records in Arkansas, Alabama, Tennessee and Kentucky - the hardest-hit states, according to Associated Press.

Still, meteorologists said there is not enough recorded historical evidence of such storms to blame global warming at this point, but Tuesday’s tornadoes had all of the key deadly elements: warm air near the ground; high winds; and warm moist air coming north from the Gulf of Mexico.

Schaefer told Associated Press, La Nina doesn’t specifically cause tornadoes, it helps shift the jet stream, pushing storms from the West and moisture from the Gulf into the necessary collision course over the South. El Nino, La Nina occurs every few years, and has been changing global weather patterns for a few months now, Mike Halpert, deputy director of the Climate Prediction Center, which monitors La Nina, told Associated Press.

Preliminary figures for January show 136 tornadoes, five tornado deaths and three killer tornadoes, although these figures tend to drop after closer analysis.

Between 1997 and 2007, the average February has 30 tornadoes, killing 9 people. Early reports tallied 68 tornadoes so far this month. "We're off to a big start for the year," said Greg Carbin, a meteorologist at the storm center. Meteorologists said that the patterns point to the likelihood of more tornado outbreaks this season. "As long as the pattern remains the same it can be very active," Schaefer said. "It's not a time to let down your guard."

MARITIME NOTES:

Shell Oil to put sensors on Gulf rigs to gauge storm strength, share data with forecasters

Maya Bell
Sentinel Staff Writer
February 14, 2008

MIAMI - It's a Gulf Coast nightmare: A moderate hurricane crosses a pocket of deep warm water in the Gulf of Mexico and explodes into a top-of-the-chart Category 5 monster.

Exactly how and why that happens may become a bit clearer one day, thanks to new undersea sensors Shell Oil Co. has agreed to install on one of its oil platforms in the Gulf south of New Orleans.

Known as "thermistors," the instruments will measure heat content of the water to a depth of 100 meters, or about 330 feet, and may be operable by this fall, in time for the peak of the 2008 hurricane season. The data could help hurricane scientists measure the effects of warmer water on storm intensity.

They are one piece of a nearly $1 million investment the oil company is making to collect data for hurricane research, forecasting and coastal-resource management.

Marking the first private-public partnership of its kind, Shell has agreed to acquire and install weather and oceanic data-collecting sensors on seven of its oil and gas facilities in deep waters off the Gulf Coast from Texas to Alabama.

The National Oceanic and Atmospheric Administration has agreed to make the data available in real time to its National Weather Service forecast offices, the National Hurricane Center west of Miami and the public.

"This is very significant," said David Miller, a NOAA spokesman in Washington. "These platforms are designed for maximum survivability, and having an uninterrupted data stream even in the height of a hurricane could have untold value."

Under federal law, 59 deep-water gas and oil platforms operating in the Gulf already are required to collect and transmit observations of ocean currents to NOAA's National Data Buoy Center. But the agreement between NOAA and Shell, forged after NOAA administrator Conrad Lautenbacher and Shell President John Hofmeister met at a 2006 summit on the Gulf and discussed how their organizations could leverage their strengths, goes much further.

In addition to the ocean heat sensors, by next spring Shell will install transmitters, complete with battery-backup power, on four platforms that will send sea-surface and air temperatures, pressure and wind speed to NOAA's geostationary satellites -- even if the platforms are evacuated because of a hurricane. Tethered to the sea bottom by cables, the platforms can twist in a figure eight to withstand storm-force currents and winds.

Shell also has agreed to collect and share meteorological data from two Continental Shelf locations off Louisiana and install high-frequency radar transmitters on platforms off the Texas coast. Specific locations have yet to be identified.

Because Florida waters are off limits to oil drilling, only one of the platforms scheduled for the enhancements is near its coast, south of the Alabama-Florida border. Still, the Sunshine State should benefit.

"Think about it: More than half of Florida's real estate is on the Gulf of Mexico," said hurricane-center spokesman Dennis Feltgen. "And storms don't always move west. Sometimes they come from the west. Remember Wilma," a reference to the 2005 late-season storm that swept across southwest Florida and exited over Broward and Palm Beach counties.

While Shell spokeswoman Darci Sinclair said the thermal sensors should help hurricane forecasters improve on their weakest skill -- predicting the intensity of storms -- forecasters said the data will likely be of more use to researchers. But they'll be glad to have it.

"Every meteorologist always wants every bit of data he or she can get," hurricane specialist James Franklin said.

Maya Bell can be reached at mayabell@orlandosentinel.com or 305-810-5003.

Riverdance bye-bye

GROUNDED cargo ship, the Riverdance, is expected to set sail this week - and it couldn't come quick enough for local residents.

Locals living in the English holiday town of Blackpool have experienced the same tourism fever Newcastle locals had when the Pasha Bulker ran aground last year.

Blackpool's promenade has become a "nightmare" with locals complaining of traffic jams as people across England travel to see the Riverdance, an Irish-owned ship which has been grounded for 17 days.

"When it first happened it took me 45 minutes to get down the road to get home. The parking is a nightmare too," Blackpool local Steven Wilkinson said.

"It'll be worse this week with half term holidays. You can't blame people for coming to see the ferry though. It's a one off and their kids want to see it."

It's not only the locals who are complaining. Sightseers say they are finding it difficult to park in the small seaside town.

"I've come every day to see the ferry. It's jolly good to see so many people here. But there are a lot of cars. People living here know where to go for parking spaces, but visitors wouldn't know where to park. There aren't enough spaces," visitor Clarice Dale told the Blackpool Gazette.

Small business owners will be sad to see the Riverdance go.

"Our business has doubled. The longer it's here, the better it is for us. It's been great for business, you don't need to advertise the area - just put a boat on the beach! " Ann Wilkinson, owner of Blackpool's The Eating House said.

Four passengers and 10 crew were airlifted off the Riverdance in a rescue which included the coastguard, the Royal Air Force and lifeboat services.


RS