National Weather Service United States Department of Commerce

Heavy Rainfall Threat Continues in the Southwest on Monday; Record Warmth in the Plains and Midwest

Remnant moisture from Tropical Storm Rachel will persist over portions of the Great Basin and Southwest on Monday, bringing a potential heavy to excessive rainfall risk. Well above average and potentially record breaking temperatures will develop across the Plains and Midwest early this week, spreading into the Lower Mississippi Valley and Southeast midweek. Read More >

Automatically generated image showing areas of storm relative helicity.

 

Thumbnail of an automatically generated image showing areas of storm relative helicity. Thumbnail of an automatically generated image showing areas of storm relative helicity. Thumbnail of an automatically generated image showing areas of storm relative helicity.
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4 Panel Display | Animated Loop

Helicity (0-1 Km) 

This is the 0-1 km (approximately 0-3,000 Ft. AGL) storm relative helicity which is a measure of the amount of low level wind shear available for tornadogenesis. This is not a good indicator of supercell potential which is related more strongly to 0-6 KM vertical shear. Values greater than 100 m**2/s**2, do suggest an increased threat of tornadoes provided a supercell is present.  Larger values are generally better, but there are no clear "boundaries" between non-tornadic and significant tornadic supercells.

The arrows indicate the approximate right supercell storm motion using the Bunkers technique.

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