, Georgia, with another landing behind it, during reployment for Hurricane Katrina. The 53rd Weather Reconnaissance Squadron, using the call signs
Teal 70 to
Teal 79, flies missions into
hurricanes and weather systems for research purposes and observation. Although
satellite data has revolutionized
weather forecasters' ability to detect early signs of tropical cyclones before they form, there are still many important tasks for which this information is not suitable. Satellites cannot determine the interior
barometric pressure of a hurricane, nor provide accurate wind speed information. These data are needed to accurately predict
hurricane development and movement. Because satellites cannot collect the data and ships are too slow and vulnerable, the only viable way to collect this information is with aircraft. Meteorological parameters measured, in order of priority, are: • Geographical position of the flight level vortex center (vortex fix) and relative position of the surface center, if known; • Center
sea-level pressure determined by
dropsonde or extrapolation from within of the sea surface or from the computed 925
hPa, 850 hPa, or 700 hPa height; • Minimum 700, 850 or 925 hPa
height, if available; • Wind data (continuous observations along the flight track) for surface and flight level; • Surface wind data from
Stepped-Frequency Microwave Radiometer (SFMR); • High density three-dimensional
Doppler radial velocities of the tropical cyclone core circulation; • Temperature at flight level; • Rain rate from SFMR; •
Sea surface temperature; and •
Dew-point temperature at flight level. The 53rd WRS is equipped with ten pallet-instrumented WC-130J aircraft to collect the required meteorological data. The area of responsibility for the "Hurricane Hunters" is from midway through the Atlantic Ocean west to the
Hawaiian Islands, although they have also been tasked to fly into typhoons in the Pacific Ocean on occasion, as well as gather data in winter storms. The Hurricane Hunters are tasked to support 24-hour-a-day continuous operations with the ability to fly to up to 3 storms at a time with a response time of 16 hours. This necessitates a mission organization of ten full-time aircrews and ten part-time. The 53rd WRS uses
Henry E. Rohlsen Airport on
St. Croix as its primary forward-deployed location for North Atlantic basin operations. Each May since 1996, when it switched operations from
Antigua to the
U.S. Virgin Islands to operate from U.S. soil, the squadron prepositions maintenance equipment and materiel at Rohlsen in preparation for the coming season. From July through September three crews are commonly forward-deployed to St. Croix at any given time with rotations of a week's deployment per month. Since 1969, the 53rd WRS also performs winter storm weather reconnaissance off both coasts of the United States between 1 November and 15 April in support of the
National Centers for Environmental Prediction. These missions are flown at the WC-130's
service ceiling of , which subjects them to turbulence, lightning and icing. The crews collect data ahead of weather systems, dropping
weather buoys along their routes, before they move off the eastern seaboard to help determine if the conditions are right to intensify into
Nor'easter blizzards. In 1997 and 1998, the Hurricane Hunters also flew winter storms in the
Gulf of Alaska. The predetermined tracks are six to eleven hours in duration, with one to three missions flown per major winter storm event. Coverage of winter storms in the eastern Pacific has become standard during the month of February, operating
TDY from either
Elmendorf AFB, Alaska, or
Hickam AFB, Hawaii. staff discuss Hurricane Hunter aircraft operations aboard an Air Force Reserve WC-130J Super Hercules The 53rd WRS works closely with the
National Hurricane Center (NHC), a division of the
National Weather Service (NWS) located in
Miami, that tracks hurricanes to provide early warning service for
Atlantic basin storms. It maintains a subunit, the
Chief, Aerial Reconnaissance Coordination, All Hurricanes (CARCAH), at the NHC as a point-of-contact and provides the staff and equipment to coordinate Department of Commerce requirements for hurricane data, assign weather reconnaissance missions and monitor all data transmitted from weather reconnaissance aircraft of DOC and the 53rd WRS. The 53rd WRS maintains similarly configured
satellite communications ground stations within CARCAH at the NHC and its facility at Keesler to receive and process data from the aircraft. The Keesler ground station is maintained as a backup to the primary system at NHC, which has greater
data streaming capability, and would be manned by CARCAH personnel in the event of a long-term satellite communications failure at NHC. During temporary outages, 53rd personnel at Keesler act as operators and relay data from the aircraft by land line to the CARCAH ground station. Processed data is transmitted to the Weather Product Management and Distribution System (WPMDS) of the
Air Force Weather Agency at
Offutt AFB,
Nebraska, which then relays it to the NWS Telecommunication Gateway at
Silver Spring, Maryland, for worldwide distribution. The Keesler site has direct communications capability with WPMDS in the event of land line/internet failure between Keesler and the NHC. The system also provides backup transmission paths to WPMDS using local NHC servers and satellite connection to Keesler in the event of internet outages, except if an outage originates at Offutt.
Tropical cyclone operational profiles When a tropical disturbance becomes suspect for development as a tropical or subtropical cyclone, the NHC assigns the system a
temporary tracking ("Investigation") number and requests the 53rd WRS to determine if the winds are blowing in a counterclockwise rotation, indicating a "closed
cyclonic circulation". This investigative mission is flown at an altitude of above the ocean surface in a pattern designated by the ARWO aboard the mission WC-130 based on observed conditions. The ARWO, using a
stepped-frequency microwave radiometer (SFMR, or "smurf"), continuously monitors ocean waves to determine wind speed and direction. The low-level wind and pressure fields provide an accurate picture for NHC forecasters. Investigative missions are usually flown during daylight and may be timed to arrive in the investigative area at first light in the morning or last light in the evening. Weak pressure gradients, large areas of calm, and light winds in areas of heavy convective activity often make vortex fixes difficult to obtain in areas of weak circulation, challenging the skills of the crews. of
Hurricane Melissa Once NHC determines that there is circulation within the disturbance, the mission becomes a sequentially numbered "fix" mission, conducted initially every six hours by rotating flights in cooperation with NOAA missions, and then at three-hour intervals as the storm moves within specified parameters. During the "fix" mission, the ARWO directs the aircraft to the true center or
vortex of the storm by monitoring the radar presentation, temperature, pressure, and mapping the wind fields as the aircraft makes left-hand turns. Vortices determined by individual parameters including visual observation may not coincide at the same geographic location. Surface and upper-level centers may be displaced by many miles. In order to make a reliable evaluation of its size and configuration, the crew flies through the disturbance using "Flight Pattern Alpha" consisting of
intercardinal headings with legs in length. The Alpha pattern is repeated at least twice during the mission, which will typically see a penetration of the eye of the system four times. Patterns may also be adjusted to meet circumstances encountered in the system. In August 2011, as
Hurricane Irene neared the
Delmarva Peninsula between landfalls, a 53rd WRS ARWO directed a pattern with shorter legs and more rapid turnarounds because of the proximity of land, making seven center fixes in one flight. ==Lineage==