National Weather Service United States Department of Commerce

Heat Wave Expands to the East Coast; Flash Flooding Likely in the Central Plains into the Midwest; Severe Thunderstorms in the Northeast

Dangerous, prolonged heat is ongoing in the Mid-South to Mid-Mississippi Valley and heat expands into the Northeast for a brief period today. Widely scattered instances of flash flooding due to heavy rains are forecast from northeast Kansas to much of Indiana. Scattered strong to severe thunderstorms are possible across parts of New England, northern Mid-Atlantic, and North Dakota. Read More >

12-hour helicity forecast

 

Figure 12: ETA 12 Hour Forecast of Surface to 3 kilometer Helicity
and Boundary Layer Wind valid 1200 UTC May 12, 1997.

 

18-hour helicity forecast

 

Figure 13: ETA 18 Hour Forecast of Surface to 3 kilometer Helicity
and Boundary Layer Wind valid 1800 UTC May 12, 1997.