Researchers rise to challenge of predicting hail, tornadoes three weeks in advance

In a new paper in Journal of Geophysical Research: Atmospheres, Colorado State University atmospheric scientists demonstrate the ability to make skillful predictions of severe weather across the Plains and southeastern United States, including hail and tornadoes, in that coveted 2-to-5-weeks-in-advance period. To do it, they use a reliable tropical weather pattern called the Madden-Julian Oscillation, which can influence weather in distant parts of the Earth, including the U.S., by sending out powerful atmospheric waves.

Weather forecasting weeks in advance cannot pinpoint where individual tornadoes or hail storms will occur, Baggett explained, but the researchers have shown they can forecast expected environmental conditions that are favorable for the formation of severe thunderstorms. That includes atmospheric instability and rotational vertical wind shear.

To understand whether this new method of predicting severe weather would be useful to forecasters, the researchers hope they can transition the work to operational experts who could test it out. "In essence, these forecasts of opportunity would allow a forecaster to better alert the public of a period in which severe weather may be more likely a few weeks in advance," Childs said.

https://www.sciencedaily.com/releases/2018/11/181128192143.htm