High Tech Weather Forecasting

Meteorologists Use NEXRAD, Satellites, X-ray, GPS, Computer Modeling

Mar 28, 2008
Aurae Beidler

GOES Image of Earth - NASA-GSFC, data from NOAA GOES

Meterologists use radar images from NEXRAD and satellite data from GOES, TRMM, GPS and NASA's QuikSCAT blended with computer modeling predictions to make daily forecasts.

NEXRAD

National Weather Service or NWS operates the NEXRAD system, or Next Generation of Radar, with assistance from the Department of Defense and the Federal Aviation Administration. NEXRAD was launched in 1988, with the WSR-88D (Weather Surveillance Radar 88 Doppler) by NWS. With a Radar Operations Center in Norman, Oklahoma, NEXRAD contains 158 operational radar systems across the United States, ready to aid meteorologists in tracking weather systems and making predictions.

NEXRAD helps meteorologists dissect potential severe thunderstorms, evaluating intensity and variations throughout the different altitudes of the cell. This ability to study the developing storm, helps meteorologists issue watches and warnings in a more timely manner.

Yet, gaps in radar coverage across the United States, limit the precision of the NEXRAD system. Topography such as mountain ranges, block radar scans. Low lying storms in valleys and off the Pacific coast also produce limited radar scans.

Satellite

Satellite data is used by meteorologists for storm tracking and weather prediction. The GOES or Geostationary Operational Environmental Satellites, operated by NASA and NOAA, provide coverage of North America and the Atlantic Ocean. These small satellites follow the Earth’s orbit, quickly scanning thousands of square miles in just several minutes. The satellites measure ocean temperatures, track storms and provide valuable data on weather. The next series of GOES satellites are set to launch this spring, with improved capabilities using digital information.

X-ray

The TRMM or Tropical Rainfall Measuring Mission, an endeavor by the United States and Japan is considered a “next-generation satellite” able to scan rainfall rates, lightning data, storm intensity and study the interior of hurricanes. The TRMM sits 218 miles up in the sky, using a “combination of passive microwave and active radar sensors” (NASA, 2008) to monitor global rainfall. TRMM also provides useful climate data, improving climate modeling. TRMM monitors El Niño and La Niña conditions.

NASA's QuickSCAT

NASA’s QuikScatterometer or QuikSCAT, launched in 1999, aids meteorologists in improved 2-5 day forecasts, with more accurate data. The satellite provides measurements of ocean surface winds by “by sending radar pulses to the ocean surface and measuring the "backscattered" or echoed radar pulses bounced back to the satellite” (NASA, 2008). The QuikSCAT also studies polar ice pack, providing valuable climate data.

GPS

GPS or Global Positioning System, first used by the Department of Defense, is a system of 28 satellites. Although it is best known as a navigation tool, GPS is also a valuable climate and weather data tool. Meteorologists use these GPS satellites to measure soil moisture, sea ice, monitor ocean waves and surface winds.

Computer Modeling Using AWIPS

A massive amount of data and calculations arrive at weather prediction centers, containing weather, hydrological, radar, satellite and weather balloon data. Meteorologists need a way to evaluate and process the information. The National Weather Service uses a system of information processing called the Advanced Weather Information Processing System, or AWIPS. AWIPS integrates all the information into a variety of computer models. Using measurements of temperature, wind speed, precipitation and satellite data to computers generate predictions. Meteorologists can blend predictions to generate a specific forecast.

With all of the available weather data, meteorologists have improved the accuracy of forecasts over the past 20 years. However, there is still room for improvement. New radar systems and satellites are being developed now, in order to aid meteorologists with storm tracking and more accurate forecasts.