ST. CROIX, U.S.V.I. (AFNS) -- Members of the Air Force Reserve Command's 53rd Weather Reconnaissance Squadron deployed to their detachment here recently to fly training missions over the Caribbean in preparation for the 2009 hurricane season.

Unit Airmen are part of the 403rd Wing located at Keesler Air Force Base, Miss., and are the only Department of Defense unit flying into tropical storms and hurricanes collecting critical data.

During the next months, until Nov. 30, the Hurricane Hunters will be honing their skills in special WC-130J Hercules aircraft, ready to fly when called upon by people in the liaison office at the National Oceanic and Atmospheric Administration's National Hurricane Center in Miami. The Airmen are the only ones in the Air Force authorized to fly in thunderstorms,

"We can be deployed within 16 hours after the call (from the NOAA liaison office)," said Lt. Col. Louis Patriquin, the 403rd Operations Group commander.

Their mission is to collect storm data and send to the hurricane center for forecasters to plug into computer models for better forecasting predictions. According to AFRC officials, one hurricane mission can pay for itself and more by the money it saves in unnecessary coastal evacuations. For example, officials estimate that it costs about $1 million to evacuate the residents of a single coastal mile.

If the 53rd WRS Airmen can reduce the evacuation area by 100 miles, the squadron's entire flying budget is covered by one hurricane. Money and lives also are saved by not evacuating people who aren't in the storm's path. Evacuating people can cause deaths, not just from the storm, according to Bill Reid, National Weather Service director. Pinpointing accurate landfall is paramount for all.

Depending upon the location of the storm, the base of operations can be at Keesler AFB, Homestead Air Reserve Base, Fla., or St. Croix. Each of the Hurricane Hunter weather missions averages about 11 hours and can cover nearly 3,500 miles.

"Having an operating center in St. Croix allows us to fly longer in the storms that are near here. It would be impractical to fly the mission from our home base at Keesler," said Lt. Col. Roger Gardner, aircraft commander for these training missions.

While the aircrew flew a series of weather training scenarios, each of the aircrew echoed the same sentiment, "You can't learn to fly in a hurricane until you do."

"These training missions prepare us as we go over checklists so that the actions are second nature when we are flying in a real-world mission," Lt. Col. Mark Stevens, navigator, said.

The Airmen have figured out to fly safely into the storms they fly an approach called "crabbing," flying almost sideways in the eyewall of the storm.

"The mission dictates that we fly into a lot of really bad weather and most pilots do their best to avoid the really bad weather. You pay lot closer attention to your thunderstorm penetration airspeed and what the environment is doing to you," said Colonel Gardner, who has been flying with the squadron for 26 years.

This airspeed is important as are changes with the weight of the airplane; too slow and the aircraft might stall in turbulence, but too fast and it will be too stressful on the aircraft's frame.

"We have our moments where we have a really rough ride. We're subjected to a lot more lightning than a normal flight so that might seem to make it more dangerous," Colonel Gardner continued.

"If you are flying the airplane the way it's meant to be flown in that environment, we minimize the risks," he said. "Is it inherently more dangerous than flying on a nice clear day? Probably -- but we don't look at it from that point of view."

One of the most important things the Hurricane Hunters do is to track a tropical storm, tropical depression or hurricane and send the data to the hurricane center for forecasters to learn more about the storm.

Hurricanes are composed of dense thunderstorms with severe turbulence and heavy rain. A solid ring of thunderstorms called the "eyewall" usually surrounds the eye. This is where the strongest winds are commonly found. By contrast, the eye is comparatively calm and virtually cloud-free.

"Most of these (weather) instruments are standard to the WC-130J model except for a couple of special instruments that have been added. One is the stepped-frequency microwave radiometer," said Lt. Col. Val Hendry, who has been an aerial reconnaissance weather officer, or AWRO, for 23 years.

The SFMR continuously measures surface winds by measuring how much foam is being kicked up by the wind and by rainfall rates occurring below the aircraft. The other extra sensor is the dewpoint hygrometer, which measures the amount of moisture in the air.

The first missions are flown at low levels between 500 and 1,500 feet. They determine if the winds near the ocean surface are blowing in a complete counterclockwise circle and also pinpoint the center of this closed circulation, the first stage of a developing tropical depression.

As the storm strengthens, they enter at higher altitudes as the storm becomes more severe. When a tropical storm has winds of 39 mph, it gets a name. A hurricane will have wind speed of 74 mph or higher.

The tops of the storm clouds may reach 50,000 feet, so the aircraft does not fly over the storm, but right through the thick of the weather to collect the most valuable information from the eye. The aircrew flies higher for the added margin of safety, more space to bounce around and to stay below freezing and avoid ice on the plane.

Another tool is the dropsonde, an aerial weather device that is dropped from the aircraft. It has a parachute on one end to keep the cylindrical instrument vertical.

"They have a global positioning system, and when they are free falling, they are sending wind direction, relative humidity, temperature, pressure and speed of the storm to the dropsonde computer station," said Tech. Sgt. Troy Bickham, dropsonde system operator/weather reconnaissance loadmaster.

The cylinder doesn't go straight down; the winds of the storm may carry it halfway around the storm before it lands. Once it hits the water the data stream ends. It is biodegradable and it's not retrieved.

The dropsonde system operator then sends that information to the ARWO for analysis. Additional information bursts are sent every 10 minutes to the hurricane center by satellite to provide the most accurate measurement of the storm's location and intensity.

The crew will fly a pattern with a big "X" centered on the eye, with each leg 105 miles long, so the squadron can map out the extent of damaging winds on each side of the storm.

Colonel Hendry provides a good analogy for the Hurricane Hunter's work. Forecasters can only do so much with satellite imagery. She said to imagine a doctor trying to make a diagnosis by examining you through a window. Wouldn't it be better if the doctor had information about your temperature, blood pressure and other medical data to make an accurate diagnosis?

"We help the hurricane center improve their forecasting models," she said. "By 'initializing' them, we report where and how strong the storm is right now, and that enables the computer models to make a more accurate prediction of what the storm will do in the future."

The crew consists of two pilots, a dropsonde operator/weather reconnaissance loadmaster, a weather officer and a navigator. During an active hurricane, squadron aircrews work around the clock sometimes with one aircrew on rest, another leaving for a mission and another arriving. It is entirely possible to cover five missions in one day, especially if more than one storm is going on at a time, according to squadron officials.

The Reserve squadron has 20 aircrews, but its composition is unusual for a Reserve unit. Fifty-nine unit members hold air reserve technician positions, civilian employees in the Air Force Reserve, which allows the fast reaction time. The rest of the squadron is made up of Air Force reservists.

The Hurricane Hunters provide surveillance of tropical disturbances and hurricanes in the western Atlantic Ocean, Caribbean Sea, Gulf of Mexico and eastern Pacific for the National Hurricane Center. They also may fly missions for the Central Pacific Hurricane Center in Honolulu.

From Nov. 1 through April 15, the unit also flies winter missions off both coasts of the United States, along with aeromedical evacuation and cargo missions.