National Weather Service United States Department of Commerce

Strong to Severe Storms in the Upper Midwest; Bering Sea Low Continues to Impact Southwest Alaska

Scattered severe thunderstorms are possible Thursday across central and eastern Minnesota, Iowa, and western Wisconsin. A few tornadoes, isolated very large hail, and damaging winds may occur. In southwest Alaska, a Bering Sea low continues to cause strong winds, significant rainfall, and high seas, with further impacts expected Friday into the weekend from a North Pacific storm. Read More >

Automatically generated image showing areas of surface-1km vertical shear.

 

Thumbnail of an automatically generated image showing areas of surface-1km vertical shear. Thumbnail of an automatically generated image showing areas of surface-1km vertical shear. Thumbnail of an automatically generated image showing areas of surface-1km vertical shear.
Hour - 1 Hour - 2 Hour -3

4 Panel Display | Animated Loop

Shear (0-1km) 

Surface-1-km Vertical Shear is the difference between the surface wind and the wind at 1-km above ground level. These data are plotted as vectors with shear magnitudes contoured. 0-1-km shear magnitudes greater than 15-20 knots tend to favor supercell tornadoes.

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