Tracking tropical cyclones is a constantly evolving science. Different methods include using satellites and radar, as well as reconnaissance aircraft. Observations from across the Caribbean also greatly assist in tracking tropical cyclones.
The National Hurricane Center is a primary source of forecasts of tropical systems. See how they use information gathered to forecast the track of a tropical storm or hurricane.
Using SatellitesPrior to technology used to develop and launch satellites, it was difficult for meteorologists to determine just where tropical cyclones were forming. They relied on ship and tropical island weather observations and coastal radars.
The first satellite sent up by the United States to monitor weather conditions was TIROS in 1960. TIROS' capabilities are primitive compared to today's satellite technology, but it opened the door for meteorologists to understand a great deal more about tropical cyclones.
The story of Hurricane Camille illustrates advances in weather information learned through the use of satellites. In 1969, meteorologists did not know as much about the appearance of hurricanes on satellite images as they know today. It was thought that the larger the overall cloud pattern appeared on the satellite image, the more intense the tropical cyclone might be.
Hurricane Camille's cloud pattern did not cover a large area. Based upon the belief that the larger the cloud area, the stronger the storm, meteorologists did not realize they were dealing with a Category 5 hurricane until reconnaissance pilots flew into its eye and discovered Camille's extraordinary intensity.
Meteorologists soon realized symmetry of cloud patterns and the character of the hurricane's eye relative to the CDO (Central Dense Overcast) that provided a better estimate of tropical cyclone strength.
Satellite images are very important to forecasters because by putting several hours of satellite pictures into motion, they can gather information on the track and development of the tropical cyclone.
The newest generation of weather satellite is the GOES series. GOES-8 was launched in 1994, providing more clarity in satellite pictures than ever before. It provides forecasters with updated satellite images at least twice each hour.
With the launch of GOES-9 in 1995, forecasters now have full satellite coverage of the U.S. Atlantic coast and the Pacific coast out beyond Hawaii. The GOES-L series will be launched soon and provide another improvement in satellite monitoring of tropical cyclones.
Using Doppler RadarNew Doppler radar can detect rain associated with tropical cyclones. It typically covers rain within a 200 to 250 mile distance from the radar location and provides estimates of rainfall amounts and depicts hurricane's rain bands, its eye and its eye wall.
The newest generation of Doppler radar provides forecasters with improved data on the movement of tropical cyclones, tornado activity that can accompany a tropical cyclone, and estimates of wind speed within a tropical cyclone.
Reconnaissance AircraftDevelopment of both radar and technologically advanced military aircraft made it possible to gather data in a new way. During World War II, Army Air Corps and Navy pilots began making reconnaissance flights into the eye of hurricanes to obtain information on a hurricane's location and intensity.
Today, reconnaissance aircraft are still actively used to gather tropical cyclone information, which is then passed on to the National Hurricane Center (NHC) in Miami, Florida, and to The Weather Channel.
Reconnaissance flights into tropical cyclones are made by Air Force reserve pilots and by pilots of the National Oceanic and Atmospheric Administration.
The Air Force Reserve 53rd Weather Reconnaissance Squadron is based at Keesler Air Force Base near Biloxi, Mississippi. The "Hurricane Hunters" averaged 86 missions and 1,100 hours from 1984 to 1994. However, since 1995, they have had busy seasons. For example, between January 1995 and November 1, 1995, they flew 157 missions totaling 1,847 flight hours!
Flying out of MacDill Air Force Base in Tampa, Florida, NOAA's Aircraft Operations Center (AOC) consolidates all aviation assets operated by the National Oceanic and Atmospheric Administration (NOAA).
Aircraft provide unique work platforms to NOAA's scientists, collecting environmental, geographic, and atmospheric data essential to NOAA hurricane, tornado, and cyclone research. They provide aerial support of coastal and aeronautical charting, as well as aerial surveys for hydrologic research and marine mammal population prediction.
Reconnaissance aircraft are sent out to monitor tropical cyclone activity in the Atlantic Ocean and in the central Pacific Ocean when Hawaii is threatened. Some information is received from dropsondes. A dropsonde is a radio-like instrument dropped from the reconnaissance plane into a tropical cyclone. It records wind speed and direction, air pressure, air temperature readings, and altitude of these quantities. Dropsondes are just one part of information provided by reconnaissance aircraft gathers throughout the mission.
ObservationsBefore technology provided meteorologists with radar and satellite imagery to track hurricanes, sketchy information made it difficult to know where tropical cyclones would make landfall, increasing the probability that the public would be poorly warned or unwarned altogether.
Formal installation of a national hurricane warning system was initiated by the U.S. Weather Bureau just before the turn of the century. Early information was provided through manned weather stations in the West Indies, Cuba and Mexico.
These stations relayed local tropical weather information throughout hurricane season. Although data gathered at these locations provided useful information about tropical cyclone intensity, stations did not provide enough information to determine where storms might head next.
As ships became equipped with radios, they became actively involved in providing the U.S. Weather Bureau with tropical cyclone observations.
Currently, data buoys placed throughout the Gulf of Mexico and along the Atlantic and Pacific seaboards relay by radio signals and/or via satellite information including air and water temperature, wind speed, air pressure and wave conditions. Although data buoys are used for more than just predicting and monitoring tropical cyclones, they do provide very valuable information during hurricane season.
Check parameters used by tropical meteorologists to forecast developing tropical cyclones.