The season for hurricanes and violent summer thunderstorms has arrived. Treasure Coast residents might breathe easier knowing that the National Weather Service in Melbourne has new radar to improve its ability to warn of approaching storms. John Pendergrast, that station’s senior meteorologist, explains what the radar is and how it works.
Q. What advantages in forecasting will meteorologists get from the new three-dimensional radar?
A. Dual-polarimetric radar imagery — Dual Pol for short — has been available to National Weather Service meteorologists in Melbourne, as well as the public, since early this year. The weather radar is located at Melbourne International Airport, adjacent to the service’s office. It covers all of east-central Florida out to 80 miles beyond the coast. It transmits and receives energy pulses in a horizontal and vertical orientation. Since the radar receives pulses from both orientations, the size, shape and variety of targets can be better estimated. Significant improvements in the estimation of precipitation rate, discrimination between hail or rain, and the identification of non-meteorological (radar images) is possible. Dual-Pol technology will not, however, improve tornado lead times or be able to provide exact precipitation type on the ground.
Q. Are there any types of severe weather for which this new radar will be especially useful?
A. The Dual Pol technology is expected to be most useful during heavy rain episodes and during occurrences of hail. The radar can see these phenomena suspended in the cloud layer and it will allow for early detection and any needed warnings for severe storms and flooding. Also, it has been noted in other areas of the country that the Dual-Pol radar has better ability of detecting lofted airborne debris during strong tornadoes.
Q. How does radar work to track storms and how long has it been used effectively in warning people of dangerous approaching weather?
A. The Melbourne weather radar undergoes a preprogrammed scanning strategy that is adjustable by various modes, depending on the specific weather situation. There are numerous tools available to trained meteorologists at their workstation to interrogate incoming radar data. Radar data has been available from Melbourne since 1992.
Q. Is it true that many of our orbiting weather surveillance satellites are aging and not being replaced?
A. All satellites begin to age once they are placed into orbit. Geostationary Operational Environmental Satellites (GOES) provide continuous monitoring from a fixed position more than 22,300 miles above the Earth. These satellites, orbiting at the same rate as Earth’s rotation, beam down images and other measurements of air, land, water, and ice across the Western Hemisphere, allowing scientists to constantly monitor for severe weather such as tornadoes, heavy rainfall, and tropical storms. Polar Operational Environmental Satellites (POES) operate 540 miles above earth, much closer than geostationary orbits. Because the earth rotates while these satellites travel from the North Pole to the South Pole, they can collect land, ocean, and atmospheric data from across the entire globe. It’s these satellites that are the main sources of observational data used to initiate weather prediction models that are essential for accurate weather forecasts. To ensure these special satellites are always protecting our nation, next-generation satellite systems, such as the Joint Polar Satellite System and GOES-R, must be built, launched into space, and fully operating before an aging satellite reaches the end of its expected life span. Although these projects remain quite expensive, their economic as well as public safety benefits are well worth their cost. Land-based aircraft will likely never replace satellite technology completely, due to restrictions on capable flight altitude of aircraft as well as their relatively limited range of coverage.
Q. Will people ever be able to change the weather, such as defusing hurricanes and tornadoes, or is that science fiction?
A. Because the circulation wind field is such a massive scale in a hurricane, it is not likely any manmade alteration or attempted defusing of a hurricane’s intensity will ever be successful. Any attempts to interfere with tornado genesis also is virtually impossible, due to inability to safely set up or pre-stage equipment and personnel in advance of a developing tornado.
More Safety Info:
- Experimental Severe Weather Warnings Project
- Severe Weather Awareness Week: Watches Vs. Warnings
- Severe weather continues to move in from Texas
- Violent weather pounds southern Kansas
- Severe weather dumps hail on parts of Martin County