National Weather Service United States Department of Commerce

Winter Storm for south-central U.S.; Critical Fire Weather in the West; Tracking Zeta

Heavy snow will continue to spread south along the Rockies through Monday. An area of freezing rain and sleet is forecast to develop over portions of the southern Plains to start the week. Meanwhile, dry and gusty conditions will continue critical fire weather conditions from California into southern New Mexico. Zeta is forecast to become a hurricane tracking north across the Gulf of Mexico. 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.
Hour - 1 Hour - 2 Hour -3

4 Panel Display | Animated Loop

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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