Naval Weather Service Association (NWSA)



An association of Aerographers & Mates,
Meteorologists & Oceanographers



By Ann Keeton, Wall Street Journal, September 12, 2007


New technology on the ground and in the air is giving meteorologists better tools to measure the size and strength of hurricanes before they hit land, potentially saving lives and millions of dollars.


Among the innovations is one that allows measurement of surface weather conditions from 10,000 feet up.  And one result of the data has been the ability to better determine how much of a coastal area should undertake a costly evacuation.


The improvements are even more important because weather experts have forecast a long-term cycle for hurricane seasons, which run from June through

November, to include more storms than usual for the next 20 years or so, due to warmer ocean temperatures.


This year, the National Oceanic and Atmospheric Administration, the government's weather research arm, expects between seven and nine hurricanes to form in areas that could affect the U.S.  That includes between three and five major storms of category 3 or higher, with winds of 111 to 130 miles per hour and a storm surge pushing waves six to eight feet higher than normal.

There is no way to tell where the storms may originate. All hurricanes start in the ocean as small tropical storms. Once hurricanes have been identified, special aircraft in the U.S. Air Force's Hurricane Hunters squadron fly into the storm to collect real-time information.  New equipment in the past two years has increased the accuracy of data by 30%, said Lt. Col. Roy Deatherage, a meteorologist in the Air Force Reserve Command 403rd Wing at Keesler Air Force Base in Mississippi .


The biggest improvement came just before Hurricane Katrina hit in 2005, when the Air Force unit upgraded its fleet of aircraft to Lockheed Martin Corp.'s C-130J planes.  Lt. Col. Deatherage said the aircraft are faster and safer in turbulent air than their predecessors.  The C-130J cockpit can also accommodate a wider range of technical devices.


Lt. Col. Deatherage flew into the eye of Katrina just as the storm hit land. "We were able to collect a higher resolution of data than ever before," he said.  "We were looking at the same data, but sampling more often as we flew."  Data are sent by satellite to NOAA's Hurricane Center .


Lt. Col. Deatherage and other pilots fly missions at an altitude of 10,000 feet.  It takes about two hours to cover an X pattern, radiating out about 100 miles on each side of the storm's center.  In 2005, a busy hurricane year, the Hurricane Hunters flew that mission 229 times.


Public affairs officer Maj. Chad Gibson said the Hurricane Hunters' missions add details to satellite pictures collected by NOAA.


"It's like a medical procedure, where the satellite photo is the X-ray, and then we do a biopsy," he said.


This year, the data grew more detailed with the addition of the Stepped-Frequency Microwave Radiometer, made by ProSensing, a private systems-engineering company in Amherst , Mass.


Nicknamed "the smurf," the radiometer was built for the U.S. Navy to measure ocean salinity.  It has since been redesigned to sense microwave radiation emitted from foam created on the ocean by winds at the surface. Computers then calculate the wind speeds based on the levels of microwave radiation.  In the past, computer models could only estimate surface conditions.


Last week, the SFMR closely followed Hurricane Felix, tracking its movement and strength.  When Hurricane Dean last month crossed Mexico 's Yucatan Peninsula , scientists for the first time were able to measure the weakening of a hurricane after it crosses over land.


Even though Dean kept moving north through the Gulf of Mexico, the storm was too weak to pose a threat to the U.S. , the scientists determined.

"The SFMR allows us to see the structure of the hurricane 36 hours before landfall," Lt. Col. Deatherage said.  Although he was surprised by its accuracy, he said the technology does have limitations.  For example, it doesn't work in shallow water.


Additional diagnostic tools are on the way.  The Air Force is considering adding an infrared system currently being fitted on C-130J reconnaissance planes for the U.S. Coast Guard.