2007 Storm Season In Review

The race was on. Was it going to become the last storm of the 2007 hurricane season (the name would be Pablo) or the first storm of the 2008 season (the name would be Arthur)?

That was the dilemma facing forecasters at the National Hurricane Center as the new year approached. An area of disturbed weather in the far eastern Atlantic Ocean was gaining tropical characteristics and might develop into tropical cyclone. But, when?

If the system was named before the clock struck midnight on December 31 st it would be called Pablo and be part of the 2007 season, and if it formed on the first day of the new year it would be named Arthur and be the first storm of the 2008 season.

“The system has been producing gale-force winds, mainly to the north and east of its circulation center,” senior hurricane specialist Richard Knabb told the Miami Herald. “It could become a sub-tropical system.”

As it turned out, the system fizzled and eventually fell apart meaning the 2007 hurricane season has officially come to a close. The final tally:

14 named storms, six hurricanes and two major hurricanes.

Still, not everyone agrees with those numbers.

“They seem to be naming a lot more than they used to,” Neil Frank, a former director of the National Hurricane Center told the Houston Chronicle. “This year, I would put four storms in the very questionable category, and maybe even six.”

Frank, now the chief meteorologist for a Houston TV station, says Chantal, Eric, Gabrielle, Ingrid, Jerry and Melissa may not deserve tropical storm status because each system had a relatively high central pressure. Each system did have sustained winds of 39 mph, the criteria to be classified as a tropical storm, but only for a brief period of time.

Frank told the newspaper that he prefers using the central pressure to measure the intensity of a tropical system, because it can be directly measured by aircraft dropping an instrument into a tropical cyclone. “In the past, we would have waited to see if another observation supported naming the system,” Frank said. “We would have been a little more conservative.”

Officials had the National Hurricane Center believe that wind speeds are the true indicator of a storm’s status. “For at least the last two decades, I am certain most, if not all, the storms named this year would have also been named,” said Bill Read, deputy director of the hurricane center told the Chronicle.

Thanks to new technology, like the QuickSCAT satellite, more accurate wind measurements are available. Read argues that it only makes sense to use the best technology to quickly determine if a system has reached tropical storm strength.

“An oncologist today would use the latest technology for determining and assessing one’s cancer,” Read said. “Would you use a doctor who only used X-rays instead of the latest MRI?”

Determining an accurate account of tropical storm activity is important in a number of areas. The insurance industry uses the numbers to help set homeowner rates, researchers need the data to determine trends in hurricane activity and scientists use the information to determine whether global warming is influencing hurricane activity.

Before the age of weather satellites, no one really knew how many tropical storms and hurricanes formed each year, especially in the far reaches of the ocean. Today, however, every suspicious swirl is closely examined, just like that disturbance in the eastern Atlantic last weekend.

Was it going to be the last storm of 2007, the first storm of 2008 or another candidate for controversy? Maybe it was a good thing it didn’t develop after all.

Tornado Tragedy

March 1, 2007 was an unusually warm day in Enterprise, Alabama, a small community in the southeastern part of the state. With temperatures expected to top 70 degrees and humidity over 60 percent, it was a sign that spring was just around the corner. For students at the local high school, the warm weather and a scheduled early dismissal couldn’t come at a better time.

Unfortunately, that balmy, humid atmosphere was a harbinger of change, the proverbial calm before the storm as a powerful cold front swept across the region. The front, which would stretch from Minnesota to the Gulf Coast, was being pushed eastward by a ferocious Jet Stream.

Those gusty upper level winds would spawn more than 31 tornadoes across several states including a huge twister that struck Enterprise High School, killing eight students and injuring dozens more. The twister collapsed concrete walls, overturned cars in the school’s parking lot and ripped apart the football stadium.

The tornado was 500 yards wide, on the ground for 10 miles and produced winds of 170 mph. It was the first killer tornado at a school since 1990 and the deadliest single twister in the United States in 40 years.

At first, school administrators came under some criticism for not dismissing the students early. Residents near the high school said they had heard warning sirens long before the tornado slammed into the high school, and school officials admit being told of the tornado threat three hours in advance.

But administrators at Enterprise High School said the weather was too violent to let the students leave the building, and they were worried that canceling classes would lead to even more carnage if the students were outside the high school when the tornado struck.

“I don’t know of anything they didn’t do,” Alabama Governor Bob Riley told reporters after touring the damage. “If I had been there, I hope I would have done as well as they did.”

Now, a six month long assessment by the National Weather Service agrees, concluding that high school officials and students followed appropriate safety measures during the tornado outbreak.

“Dismissing the students could have been just as dangerous,” said Glenn Lussky, the assessment team leader “Tornado warnings were in place the entire time, and the team agreed that shelter in place was the best response.” The report says the eight fatalities at the school were due to structural failure of the roof and walls, not the decision of the administrators.

Still, Lusky’s team says that shelter, in this case Enterprise High School, needs to have hardened safe rooms to survive future tornadoes. A hardened safe room, lined and topped with concrete, and without windows is designed to survive severe sustained winds and high wind gusts.

While a tornado the size and intensity that hit Enterprise, Alabama is virtually impossible in South Florida, comparable winds have occurred with hurricanes. In 1992, Hurricane Andrew produced sustained winds of 165 mph as it tore through southern Miami-Dade County.

More than $25 billion in damages and hundreds of destroyed homes led to new, tougher building codes. In recent years, all new schools built in the area have hardened safe rooms to act as shelters during periods of evacuations. Lusky’s team would like to see that trend grow around the country, especially in areas susceptible to large, powerful tornadoes.

“The tragic events of March 1 show that even when people have ample time and opportunity to take cover from a devastating tornado, the need for proper shelter is imperative,” said Conrad C. Lautenbacher, the head of the National Weather Service. “Despite warning lead times that exceeded national standards, many lives were lost. Our team concluded that survival in violent tornadoes often depends on reaching an adequate hardened safe room.”

Thanks to Frances, Jeanne and Wilma the term “safe room” is well known here in South Florida. Lusky and the folks at the National Weather Service would like that phrase to be commonplace around the country, too.

2007 Hurricane Season Ends Quietly

The 2007 hurricane season ended quietly on Friday without a tropical storm, disturbance or hurricane in sight. For all intents and purposes, the season really came to a close in late October when Hurricane Noel swept through the Caribbean and briefly threatened Florida.

The National Hurricane Center reports 14 storms formed this year, above the long-term average of 10 tropical storms. Still, most of the 14 were weak, short-live systems that were only a concern for shipping.

Only six hurricanes developed in 2007 with three, Dean, Felix and Humberto, making landfall. Dean and Felix reached rare category five status before slamming into Central America and Mexico. Humberto was a weak category one hurricane when it struck the southeast coast of Texas.

For the second consecutive year Florida was not hit by a tropical storm or hurricane. While Noel did get our hearts beating a little faster back in October, the storm’s biggest impact was significant beach erosion along the coastline.

Overall, folks in hurricane country along the United States coastline are more than happy with the 2007 hurricane season.

For the hurricane research community, however, 2007 will be remembered for the loss of two legends in tropical meteorology. Late last week, Herb Saffir, the man who helped create the Saffir-Simpson Hurricane Scale, died in his Miami home.

In early August, Dr. Robert Burpee, a past director of the National Hurricane Center and one of the top researchers in tropical meteorology, passed away in Miami following a long illness.

Of the two, Saffir is probably the better known thanks to the creation of his hurricane scale back in the late 1960’s. Working with Robert Simpson, the director of the hurricane center at the time, Saffir came up with a system to rank the destructive capability of a hurricane based on its wind speed and storm surge.

“Dividing hurricanes into categories was an idea whose time had come,” former hurricane specialist Mile Lawrence told the Miami Herald. “It was a wonderful way to collapse the information into a way that was easier to understand.”

Saffir also worked to strenghten building codes in South Florida and was instruemnetal in the implementation of a new state-wide building code considered the strongest in the nation.

“Driving around south Florida I can see the engineering work I have done,” Saffir told the Georgia Tech Alumni Magazine. “It’s there in the shape of buildings and bridges. It is there in the fact that the building code we use. I think I’ve left a little mark.”

There is no doubt among hurricane researchers that Dr. Robert Burpee also left “a little mark.” While he was director of the National Hurricane Center for two years from 1995 to 1997, it is in the research field that Burpee will be best remembered.

“Bob was one of those unsung heroes, a pioneer and scientist that helped shape the data we use today,” said Florida Division of Emergency Management Director Craig Fugate.

A veteran of more than 250 flights into hurricanes, Burpee was among the first who proposed using a jet to obtain environmental data around a hurricane. By sampling the atmosphere near the storm, forecasters had a much clearer sense of where the hurricane might be headed next. Max Mayfield, the former director of the hurricane center, says Burpee’s work added an additional “10 to 15 percent improvement in track forecasts.”

In 1995, Burpee helped formed the NOAA/FEMA Hurricane Liaison Team, which integrated emergency managers and hurricane forecasters to provide residents with important information. Burpee was part of countless research projects and the author of dozens of papers.

Both men’s contributions to hurricane research and safety will long be remembered as countless other top scientists build on the work of Herb Saffir and Bob Burpee.

Flying Into Hurricanes

It began as a dare, a bet among British and American pilots on July 27, 1943 as a hurricane was approaching the Texas Coast. It ended in history, as Colonel Joseph P. Duckworth became the first man to fly into a hurricane and return.

Duckworth actually flew into the hurricane twice that day, first with navigator Ralph O’Hair and a second time with weather officer William Jones-Burdick. In both cases, Duckworth’s plane encountered severe turbulence and heavy rain before breaking into the storm’s eye.

Within a few years, flights into hurricanes would become routine, an important source of information for hurricane forecasters. Today, the Hurricane Hunters, based at Keesler Air Force Base in Biloxi, Mississippi fly dozens of missions each season.

Remarkably, flying an airplane into a hurricane is not as crazy as it sounds. Still, some missions are more challenging than others. Writing in the October issue of the Bulletin of the American Meteorological Society, Neal Dorst recounts several rough rides.

On September 9, 1971 Hurricane Edith was approaching the Mosquito Coast of Nicaragua. Hurricane Hunters encountered “turbulence so severe that the pilots temporarily lost control of the aircraft,” writes Dorst. “By the time they regained control, they had lost 1,000 feet of altitude.”

During a flight into Hurricane Allen in August of 1980 the turbulence was so bad that “the shaking knocked loose the life raft and convinced one scientist that hurricane research was not his future,” writes Dorst.

Perhaps the most memorable experience in the history of the Hurricane Hunters came in September of 1989 with a flight into Hurricane Hugo. Severe turbulence in the eye wall disabled one of the plane’s four engines. “The plane had to orbit in the eye, burning fuel, while climbing to a safe altitude,” writes Dorst. The aircraft limped back to Barbados where it remained out of commission for the rest of the season.

Despite these stomach-turning examples, the Hurricane Hunters have an excellent safety record. Since the first reconnaissance missions began in the 1940’s, four airplanes have been lost in storms, the last in 1974 when an Air Force WC-130 went down in the South China Sea.

When Hurricane Noel was headed towards the Canadian Maritimes a few weeks ago, another type of hurricane reconnaissance was unveiled. The National Weather Service and NASA made history as the first unmanned aircraft flew through the storm.

The five-foot-long Unmanned Aircraft System (UAS) drone was launched from Wallops Island, Va., on a 20-hour-long mission through the hurricane. The pilotless aircraft is designed to fly into the eyewall of a hurricane at altitudes as low as 500 feet.

Scientists hope using unmanned aircraft will help fill a gap in near-surface data. The data have been hard to gather because of the safety risks of low-level flight.

“Unmanned flights at very low altitude are important since they give us unique insights and continuous observations in a region of the storm where the ocean’s energy is directly transferred to the atmosphere just above. Attempting this type of research flight with our hurricane hunter aircraft would risk the lives of our crew and scientists,” said Joe Cione, hurricane
researcher in Miami.

NOAA scientists are coordinating the unmanned flight to coincide with a manned Hurricane Hunter mission as well, providing a volume of data on Hurricane Noel from top to bottom. This level of information saturation is valuable to researchers, providing a more complete picture of storm structure and strength that becomes a valuable tool for meteorologists.

The hope, of course, is for better forecasts and increased warning time for coastal residents of an approaching hurricane.

Joe Duckworth became a legend when he accepted the challenge of British
pilots and flew into a hurricane. The first UAS flight a few weeks ago made
history, too, increasing our knowledge of tropical cyclones, the
greatest storm on Earth.

The Importance Of Weather Radios

The tornado that tore through the Eastbrook mobile home park near Evansville, Indiana on November 6, 2005 was 1,500 feet wide, moving at 70 mph and producing winds close to 200 mph. Worst of all, the twister struck in the middle of the night while everyone in the park was sound asleep.

The rare November tornado claimed 25 lives in southwestern Indiana including 20 people from the mobile home park. Residents said they couldn’t hear the tornado sirens and had no warning that a powerful storm was headed their way.

Earlier this year, the state of Indiana changed the weather warning process when Governor Mitch Daniels signed legislation requiring all mobile homes sold in Indiana must come equipped with a NOAA weather radio.

Dubbed “C.J’s. law”, for two-year-old C. J. Martin who died in the mobile home park, the new law went into effect on June 30. C.J.’s mom, Kathryn, had urged lawmakers to adopt the bill arguing that a weather radio can give residents advance warning of tornadoes.

Costing from $35 to $70, weather radios broadcast continuous weather information from the National Weather Service. When a weather warning is issued, including a tornado warning, the radio will sound an alarm, much like a smoke detector, alerting residents severe weather is in their area.

Still, the weather radio system is not ideal. Many weather radio owners turn off the device after getting fed up with false alarms and the weekly alert tests issued by the National Weather Service.

The Weather Service hopes a new weather warning system will fine-tune those weather advisories, reducing false alarms and making weather warnings more precise. Implemented last week, the new “storm-based” warning system switches from the traditional county-based warning to a more specific community-by-community alert.

“A storm-based warning focuses on a storm itself and the geographic area that might be affected by it,” said Eli jacks, a meteorologist with the National Weather Service. “We can really reduce the number of people being warned by reducing that geographic area.”

Using radar and computer modeling programs, the National Weather Service hopes to predict the moment a storm will hit a community, neighborhood or crossroad. The new alerts could reduce a warning area from thousands of square miles to a few hundred of square miles.

“It’s like shrinking the service area in a tennis court,” said John Ferree, a meteorologist with the National Weather Service in Norman, Oklahoma and one of the developers of the plan. “Even Roger Federer is going to hit the ball outside the lines if they’re close together.”

A version of the storm-based system has already been in use here in South Florida. When a severe thunderstorm is nearing Belle Glade in far western Palm Beach County, for example, only the communities directly in the path of the storm are put under storm warnings.

The system has worked well here and in trials in Indiana. “I think it has been a good system,” said Dave Tucek, who coordinates severe weather warnings in Indianapolis. “The idea being that there is no reason to warn the northern end of a county about something in the southern end of the county.”

The National Weather Service estimates the new storm-based warning system will save $100 million annually, mainly on cutting back on unneeded business closings or the amount of time people spent huddled in closets or basements during weather warnings.

More importantly, officials hope the new storm-based system will get weather advisories to people who will be directly impacted, giving folks the information and the time to prepare for severe weather.

Maybe with the new, more targeted warning system, folks will be more likely to keep their weather radios turned on, giving them a real chance to survive a tornado like the one that hit the Eastbrook mobile home park.

How Did Humberto Get So Strong?

It wasn’t supposed to be a big deal. When Tropical Storm Humberto took aim at the upper Texas coast last week forecasters were predicting periods of rain and blustery winds. Flooding was the primary concern with rainfall totals approaching ten inches expected in some areas. For folks who had gone through Hurricane Rita in 2005, Humberto was expected to be a walk in the park.

Yet, while residents of High Island and other Texas coastal communities slept, Humberto was changing, intensifying from a run-of-the-mill tropical depression into a category one hurricane. At 2 AM on September 13, Humberto made landfall with winds of 85 mph.

Humberto’s rapid intensification-from tropical depression to hurricane in 16 hours-surprised everyone, from the residents of Texas to the forecasters at the National Hurricane Center.

“To put this development in perspective, no tropical cyclone in the historical record has ever reached this intensity at a faster rate near landfall,” said National Hurricane Center senior hurricane specialist James Franklin. “It would be nice to know, someday, why this happened.”

Someday, Franklin and other scientists may figure out why Humberto strengthened so quickly. Someday, researchers will know why Felix grew from a tropical storm to a category five hurricane in 51 hours earlier this year, or why Wilma exploded from a tropical storm to a category 5 hurricane in 24 hours.

Someday they will find the answer to rapid intensification of tropical cyclones but, for now, the process remains a mystery. And, a big concern for government officials anywhere a hurricane may make landfall. Craig Fugate, director of the Florida Division of Emergency management, says that his team always prepares for a storm that is one notch up from what is predicted.

While very warm water and low wind shear probably helped with the storm’s rapid intensification, the exact reasons why Humberto went from a depression to a hurricane in such a short period of time remains a mystery. Solving that mystery is the number one priority of the hurricane research community.

“While I was the Director of the National Hurricane Center, I can say that every talk that I gave at local, state and national hurricane conferences mentioned the concern over rapid intensification,” said Max Mayfield, former director of the Hurricane Center.

Back in June, forecasters at the National Hurricane Center began using a new computer model that eventually may help with the rapid intensification issue. Called “one of the most dynamic tools” for hurricane forecasters, the Hurricane Weather and Research Forecast Model (nicknamed HWRF) utilizes advanced physics of the atmosphere, ocean and waves to predict the future track and intensity of tropical cyclones.

“Over the next several years, this model promises to improve forecasts for tropical cyclone intensity, wave and storm surge, and hurricane-related inland flooding,” said Mary Glackin of the National Weather Service. “It will be one of the most dynamic tools available for our forecasters.”

Still, neither the HWRF nor any of the other hurricane models, predicted the rapid intensification of Humberto. In fact, it is fair to say that no one saw it coming.

Back in the first half of the 20th century-before orbiting satellites, long-range radars and the much talked about computer models-hurricanes really did sneak up on people. Other than a few random ship reports residents of coastal areas had no idea a hurricane was headed their way until the wind and rain swept across the coastline.

Today, we all know when a storm is about to strike, but until the rapid intensification mystery is solved, sometimes hurricanes will be full of surprises.

La Niña On Her Way?

The odds of a busy 2007 hurricane season just went up because the water temperature in the Pacific Ocean just went down. That drop in sea surface temperature marks the likely return of La Niña, and an expected increase in stress levels for residents in Florida and other parts of the United States coastline threatened by hurricanes.

Scientists at the Climate Prediction Center announced that La Niña is on its way. “While we can’t officially call it a La Niña yet, we expect that this pattern will continue to develop during the next three months, meeting the NOAA definition for a La Niña event later this year,” said Mike Halpert, acting deputy director of the Climate Prediction Center in Camp Springs, Md.

La Niña conditions occur when ocean surface temperatures in the central and east-central equatorial Pacific become cooler than average. These changes affect tropical rainfall patterns and atmospheric winds over the Pacific Ocean, which influence the patterns of rainfall and temperatures in many areas worldwide.

“La Niña events sometimes follow on the heels of El Niño conditions,” said Vernon Kousky, research meteorologist at the Climate Prediction Center. “It is a naturally occurring phenomenon that can last up to three years. La Niña episodes tend to develop during March-June, reach peak intensity during December-February, and then weaken during the following March-May”.

While past La Nina’s have been responsible for serious droughts in the western United States, it is La Nina’s influence on hurricanes in the Atlantic Ocean and, in particular, the current hurricane season that has caught the attention of local officials.

“Although other scientific factors affect the frequency of hurricanes, there tends to be a greater-than-normal number of Atlantic hurricanes and fewer-than-normal number of eastern Pacific hurricanes during La Niña events,” said retired NOAA administrator Conrad Lautenbacher.

A 1999 study on La Nina’ influence on Atlantic hurricane activity found that “the odds are significantly higher that the U.S. will experience greater (hurricane) impacts because of a larger number of tropical cyclones and higher intensities for each storm.”

The last La Nina lasted from 1998 to 2000, a period that saw 37 tropical storms and 26 hurricanes in the tropical Atlantic. Among the memorable storms during those years were Hurricane Georges that hit the Florida Keys, Hurricane Floyd that threatened Florida and Hurricane Irene that swept across South Florida.

Dr. William Gray’s team at Colorado State University recently updated their hurricane forecast for the remainder of the season. Gray thinks the next few months will be active forecasting 10 named storms, 6 hurricanes and three major hurricanes.

This latest news regarding the developing la Nina will not sit well with residents in Florida, the northern Gulf Coast states and other locales still recovering from the active hurricane seasons of 2004 and 2005. And, while everyone received a nice break from Mother Nature last year, it appears more and more likely that the 2007 hurricane season will be busy.

All because the water temperature is going down.

Warning Residents With Unconventional Means

It may seem hard to believe, given our recent hurricane history, but there was a time, not that long ago, when a hurricane was a rare event. In the 1970’s, ’80’s and early 1990’s, a hurricane would come along only four or five times a year, often in the safe, far reaches of the tropical Atlantic Ocean.

Since 1995, however, hurricanes have become the rule, not the exception.

The National Hurricane Center reports that the 12 years since 1995 has seen more hurricanes than any other 12 year period in recorded history.

We had our share of those storms in 2004 and 2005 as Charley, Frances, Ivan, Jeanne and Wilma all slammed into the Sunshine State. The 2005 season was worse as a seemingly endless string of tropical storms and hurricanes threatened the United States.

At the top of that list, of course, were Rita and Katrina. Folks in Texas and southwest Louisiana are still recovering from the powerful storms.

The National Weather Service calls Katrina the “most destructive hurricane to ever strike” the United States. Estimates from the insurance industry topped $60 billion in insured losses from Katrina. NOAA says the storm “could cost the Gulf Coast states as much as an additional $120 billion.”

The experts who study tropical cyclone patterns and activity say this current period of above-average hurricane activity is likely to continue, perhaps for many more years. The scientists say these above-average periods run in cycles and our current cycle may last another 10 to 20 years.

With so many potential hurricanes looming in our future, helping people prepare for the storm and knowing how to react is quite a challenge for the men and women of the National Weather Service. In August of 2004, forecasters at the National Weather Service Melbourne, Florida office met that challenge head on as Hurricane Charley bore down on central Florida.

Charley, a small, but powerful Category 4 hurricane, had slammed into Florida’s southwest coast on the morning of August 13, 2005. Hours after striking Charlotte Harbor, Charley remained a destructive and powerful hurricane as it headed for the Orlando-metro area with sustained winds topping 100 mph.

Forecasters at the Melbourne weather office feared that an update on Charley’s dangerous wind conditions would get lost in the dozens of weather bulletins already issued from their office and the National Hurricane Center. Their solution was simple, yet brilliant: they put out a tornado warning.

“We ended up using a wrench for a hammer,” said Dennis Decker, the warning Coordination Meteorologist with the Melbourne office.

There was no tornado but the tornado warning got the attention of all the television and radio stations in the Orlando area. The tornado warning allowed the National Weather Service to get the word out quickly that Charley’s 100 mph winds were about 30 minutes away.

“When you do something outside of the box like that, you wonder how the people up the chain of command in the Weather Service are going to react,” said Decker. “They basically confirmed that it was a good idea.”

One of the lessons from the 2004 Hurricane season was that you don’t have to be on the coastline to be affected by the winds of a hurricane. As residents of Orlando discovered during Hurricane Charley, these monster storms can affect even the areas that many people head to, when evacuated from the coast. That presents a unique challenge to forecasters at the Weather Service, and that may require even more thinking outside the box.

Loop Current: A Hurricane Supercharger

What is that Bermuda High doing now? It is a question I heard frequently during the hurricane season.

When I spoke at weather seminars, met with residents at local malls during our hurricane expos, or was just stopped on the street, I was asked repeatedly about the Bermuda High. Hey, Mike, where’s that Bermuda High? Is the Bermuda High going to be strong again this year?

The Bermuda High, a large area of high pressure centered over the island of Bermuda in the western Atlantic Ocean, became infamous during the 2004 hurricane season for steering Charley, Frances, Ivan and Jeanne into Florida. The Bermuda High was unusually strong that year and in a perfect position to literally grab all four storms and drive them into the Sunshine State.

The exact location and strength of the Bermuda High changes from week to week and season to season. This year the high has been quite strong steering Hurricane Dean well south of the United States and into the Yucatan Peninsula.

While Floridians are often fixated on the Bermuda High, residents of the Gulf coast states are more interested in another weather phenomenon: the loop current. In 2005, the Loop Current helped create two of the most powerful and destructive hurricanes in history: Katrina and Rita.

The Loop Current is a river of very warm (over 85 degrees), very deep (2,400 feet in some areas) water that flows from the Caribbean Sea into the Gulf of Mexico, loops around to Louisiana and then exits the Gulf between Cuba and the Florida Keys.

For decades, the Loop Current has been a favorite location for fishing fleets seeking tuna and swordfish since the fish like to hang out in the warm waters. But, in recent years, meteorologists have been focusing on the Loop Current for its ability to turn an average tropical storm into a powerful monster.

A hurricane gets its energy from warm water, and therefore, the warmer the water, the higher the content of energy. When a topical system moves over a body of very warm, very deep water (like the Loop Current) its like a turbo charger for hurricanes. Suddenly, a category one hurricane can grow into a category five and do so very quickly.

Researchers at the University of Colorado traced Katrina and Rita’s path through the Gulf of Mexico and across the Loop Current. In both instances, the storm’s passage over the Loop Current’s warm, deep waters transformed the systems into category five monsters.

In the case of Rita, the hurricane had sustained winds of 90 mph before entering the Loop Current. Over the next 24 hours, as Rita passed over the Loop Current, her wind speed increased to 175 mph. Rita’s barometric pressure fell to 897 millibars, the third lowest on record in the Atlantic Basin.

When Rita moved away from the Loop Current, over somewhat cooler waters in the northern Gulf of Mexico, the storm weakened before making landfall on the Texas-Louisiana border as a still formidable category three hurricane with sustained winds of 120 mph.

Scientists say the Loop Current waters have been warmer than average during the 2005 hurricane season. They are not sure why, but they know, especially in the case of Katrina and Rita, that the Loop Current has played a crucial role in the incredible 2005 hurricane season.

Forecasters Mark 15th Anniversary Of Hurricane Andrew

It is hard to believe that is has been 15 years since Hurricane Andrew slammed into South Florida. It was Monday morning, August 24, 1992 when the category 5 hurricane hit southern Miami-Dade County.

Andrew produced more than $25 billion in damages, making it the costliest hurricane in United States history (at least, until Hurricane Katrina came along in 2005). While it was accepted that Andrew was a powerful hurricane, researchers and scientists debated for years the exact intensity of the storm. Officially, Andrew was listed as a category 4 hurricane on the Saffir-Simpson scale, with sustained winds of 145 mph.

Still, many researchers believed Andrew’s winds might have topped 155 mph, making Andrew a category five hurricane. But there was no way to confirm that in 1992 since Andrew destroyed nearly every anemometer recording device.

“Every wind instrument failed, was broke or pegged out during the storm,” said Stanley Goldenberg, a research meteorologist with NOAA’s Hurricane Research Division in Miami. “We didn’t have direct measurements, so determining the wind speed was like detective work.”

Ed Rappaport, now the acting director of the National Hurricane Center, was the detective who decided to take on the case. Rappaport didn’t have many clues to solve his mystery, just a few wind and air pressure readings, along with the damage the storm inflicted on Miami-Dade County.

“We had to piece together an estimate of what winds were which led to our existing estimate of winds around 145 mph, gusts to 175 mph,” Rappaport said.

Still, Rappaport did have one key piece of evidence. As Andrew was making landfall, a reconnaissance aircraft recorded sustained winds of 186 mph. That recording was made as the plane flew at an altitude of 10,000 feet.

Standard procedure in 1992 was to assume that surface winds were usually around 80 percent of the wind speed recorded at 10,000 feet. That would put Andrew’s surface winds at 148 mph.

Case closed, right? Well, not quite.

In 1997, researcher James Franklin, now a hurricane specialist at the National Hurricane Center, created a new instrument called a GPS dropsonde. Released into a hurricane from a reconnaissance aircraft, the new device provided researchers with some surprising data.

The data suggested that a hurricane’s surface winds are usually 90 percent of the wind speed recorded at 10,000 feet, not 80 percent as originally thought. If that formula was applied to Andrew, it would mean Andrew’s surface winds were 165 mph. That would make Andrew a category 5 storm.

“I looked at a lot of this dropsonde data,” said research meteorologist Mike Black. “If we applied the rules that we are applying to hurricanes today, Andrew would have been a category 5.”

Other scientists, especially Franklin, agree. They are convinced that Andrew was a category 5 hurricane. Yet, other researchers at the Hurricane Research Division are not as certain.

A committee from the National Hurricane Center ultimately agreed with Franklin and Black. On the ten year anniversary of Andrew’s landfall, the National Hurricane Center announced that Andrew had gained strength, and was now to be listed as a category 5 hurricane.

The committee concluded that when Andrew made landfall along Florida’s southeastern coast the storm was producing sustained winds of 165 mph. It means Andrew was the third strongest hurricane to strike the United States and one of only three hurricanes to make landfall as a category five. The other two category five storms are the Labor Day hurricane of 1935 that hit the Keys and Camille which struck Mississippi in 1969.

Andrew is now part of a very small club.