NWS Radar Hail Spike

Heat Continues for the East and South-Central U.S.; Strong to Severe Storms Across the Mid-Atlantic and Northeast

The extremely dangerous heat wave continues across the East Coast and much of the South-Central U.S. today. Record high temperatures are expected for some areas especially across the Mid-Atlantic where extreme heat risk conditions reside. There is a Slight Risk (level 2 of 5) of severe thunderstorms today for the northern Mid-Atlantic into portions of southern New England. Read More >

NWS Doppler Radar (WSR-88D) Example Products

Base reflectivity data at 0.5 degree elevation angle from the KLVX WSR-88D Doppler Radar. Reflectivity shows where and how hard it is raining or snowing, as well as precipitation intensity trends and movement. Blue and green colors represent light-to-moderate rainfall. Yellow and orange colors show moderate-to-heavy precipitation, while red is very heavy rainfall and pink and blue colors inside the red color represent hail of different sizes.

At left is a close-in view of a supercell thunderstorm over central Kentucky on March 2, 2012. The storm produced very large hail (golf ball to baseball size in diameter). Note to the south-southwest of the hail core is an elongated axis of weak returns (blue color). This axis is "down-radial" from the hail core. This is called a three-body scatter spike (TBSS), or hail spike, and is an indication that large hail is contained in the thunderstorm. However, the TBSS signature itself is not real, i.e., it is not raining where the spike is. Instead, it is an erroneous return of weak energy back to the radar after the original beam of energy from the radar hits the large hail in the storm.