National Weather Service United States Department of Commerce

Regional Outbreaks of Severe Weather Through Early Next Week; Early Season Heat Wave across the South

Active spring pattern across the center of our nation with several episodes of severe weather and heavy rainfall expected into next week. The potential for very large hail, long track tornadoes, severe wind gusts, frequent cloud to ground lightning strikes and flash flooding are in the outlook. Furthermore, dangerous early season heat wave continues for the Gulf Coast states into early next week. Read More >

Automatically generated image showing areas of 0-3 km storm relative helicity.

 

Thumbnail of an automatically generated image showing areas of 0-3 km storm relative helicity. Thumbnail of an automatically generated image showing areas of 0-3 km storm relative helicity. Thumbnail of an automatically generated image showing areas of 0-3 km storm relative helicity.
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Helicity (0-3 Km) 

This is the 0-3 km (0-10,000 Ft. AGL) storm relative helicity which is a measure of the amount of wind shear available from the ground to roughly 700 MB.   Values greater than 250 m**2/s**2 suggest an increased threat of tornadoes, but high values with this index do not necessarily suggest that the environment is supportive of supercell structures (look at 0-6 km shear).  Larger values are generally better, but there are no clear "boundaries" between non-tornadic and significant tornadic supercells.  Negative values suggest that anti-cylonic (left moving) supercells will dominate.

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