Downbursts, a specific type of strong, potentially damaging winds from thunderstorms, continue to be a challenge for forecasters, especially when storms are disorganized and short-lived. Common during the summer months in the Southeast U.S. and Southern Plains, these damaging wind events and their fast, unpredictable nature makes advance warning difficult.
Researchers at NOAA’s National Severe Storms Laboratory (NSSL) and National Weather Service forecasters are exploring how radar can help forecasters better identify which thunderstorms are most likely to produce dangerous winds at the surface. One promising approach focuses on a relatively new radar-based feature that may provide early insight into where a downburst is likely to form.
Downbursts are powerful, localized winds that originate within a thunderstorm and descend rapidly toward the ground. Sometimes mistaken for tornadoes due to the damage they cause, downbursts, unlike the rotating winds of a tornado, are straight-line in nature, radiating outward from the point of impact with the ground. PHOTO: A classic downburst is illustrated. (Georgetown, KY. July 18, 2007. NWS)
This radar signature highlights areas within a storm where the air is especially cold and dense. Since colder, heavier air sinks faster than surrounding air, these pockets can fuel stronger downdrafts. When those powerful downdrafts reach the ground, the result can be a sudden burst of damaging winds.
“We’re trying to give forecasters more information to help pinpoint which storms could potentially produce a downburst,” said NSSL Research Charles Kuster. “This radar-based signal can act as an early flag, especially when paired with knowledge about the surrounding environment.”
The effectiveness of this technique improves when combined with environmental data like temperature and humidity profiles. By integrating radar featureswith this contextual information, forecasters can make more informed decisions about where downbursts are likely to develop, and whether those winds could be especially intense.
While this tool doesn’t replace traditional forecasting methods, it could offer another layer of insight, especially in chaotic, fast-developing storm environments. Ultimately, it could help forecasters “triage” incoming storms and focus attention on those most likely to produce dangerous winds.
As research continues, NSSL scientists are working to refine this radar technique and explore how it can be integrated into real-time warning operations. The goal: better situational awareness and more lead time for these damaging wind events.
