Heavy Rainfall for Portions of the West and Central U.S.; Monitoring Fire Weather Conditions for New England

Tropical moisture continues to flow across portions of the Great Basin, desert Southwest and California. Isolated instances of flash flooding remains possible. Meanwhile, a storm and associated frontal boundary will focus showers and thunderstorms for the center of the nation. For New England, dry and breezy conditions could enhance favorable fire weather conditions. Read More >

Automatically generated image showing areas of energy helicity index.


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EHI

The Energy Helicity Index (EHI) is a number which represents the combination of instability and storm relative helicity. Our calculation uses mixed layer CAPE (surface to 3000ft average parcel) and 0-3 km storm relative helicity. Values greater than 2 or 3 have been correlated to cyclonic supercells with increased tornadic potential. Negative values are indicative of an environment favorable for anti-cyclonic (left moving) supercells, but tornadoes associated with anti-cyclonic supercells are extremely rare.

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Heavy Rainfall for Portions of the West and Central U.S.; Monitoring Fire Weather Conditions for New England

Convective Parameters - EHI