National Weather Service United States Department of Commerce

Locally Heavy Rainfall for the Carolinas; Thunderstorms and Fire Weather Concerns for Intermountain West

Heavy rainfall from scattered thunderstorms is expected across the Southwest, Intermountain West, and Plains. Isolated dry thunderstorms may initiate additional fires across the west. The coastal Carolinas may experience flash floods in the coming days due to repeated thunderstorms. Additionally, a wave of intense summer heat will hit the Southern Plains and central Gulf Coast States this week. 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.
Hour - 1 Hour - 2 Hour -3

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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