National Weather Service United States Department of Commerce

Thunderstorms and Heavy Rainfall from the Plains to the Mid-Atlantic

Severe thunderstorms producing damaging winds are most likely over parts of the Dakotas into Minnesota from this afternoon into the overnight, with other isolated storms producing hail or wind over the northern High Plains. In the Northern Plains into the Upper Great Lakes and Mid-Atlantic, heavy to excessive rain may bring flash and urban flooding through Wednesday. Read More >

Automatically generated image showing areas of the significant tornado parameter.

 

Thumbnail of an automatically generated image showing areas of the significant tornado parameter. Thumbnail of an automatically generated image showing areas of the significant tornado parameter. Thumbnail of an automatically generated image showing areas of the significant tornado parameter.
Hour - 1 Hour - 2 Hour -3

4 Panel Display | Animated Loop

Significant Tornado (SigTor) 

A composite index that includes 0-6 km bulk wind shear, 0-1 km storm-relative helicity, surface based CAPE, surface parcel CIN, and surface parcel LCL height. Values greater than 1 are indicative of increased potential of significant tornadoes.

The contours are the Lifted Condensation Level or LCL.  A lower LCL typically increases tornadic risk because it is indicative of air parcel acceleration occurring closer to the surface. 

 

Back to Convective Parameters Home