National Weather Service United States Department of Commerce

Heavy Rain and Mountain Snow Lingers in California; Winter Storm Impacting the Great Lakes and Northeast U.S.

An atmospheric river will wind down through today across California with lingering heavy rainfall, heavy mountain snow, and gusty winds. A wintry mix of freezing rain, sleet, and snow will cause hazardous travel conditions for the Great Lakes into the northern Mid-Atlantic and southern New England today through Saturday morning. Areas of tree damage and power outages are possible. Read More >

Automatically generated image showing areas of the significant tornado parameter.

 

Thumbnail of an automatically generated image showing areas of the significant tornado parameter. Thumbnail of an automatically generated image showing areas of the significant tornado parameter. Thumbnail of an automatically generated image showing areas of the significant tornado parameter.
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Significant Tornado (SigTor) 

A composite index that includes 0-6 km bulk wind shear, 0-1 km storm-relative helicity, surface based CAPE, surface parcel CIN, and surface parcel LCL height. Values greater than 1 are indicative of increased potential of significant tornadoes.

The contours are the Lifted Condensation Level or LCL.  A lower LCL typically increases tornadic risk because it is indicative of air parcel acceleration occurring closer to the surface. 

 

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