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Extreme Heat in the Central US Expands to the Southeast; Severe Weather & Flash Flooding Threats in the Plains & Upper Midwest Tonight.

Dangerous heat continues across portions of the Central and Southeast U.S. through July. Heavy rains, flooding, & severe weather are possible across the Plains & Upper Midwest to the upper Great Lakes tonight, with the heavy rain and flooding threat continuing through Friday. Tropical Depression 12W brings heavy rain to Guam & the Marianas through Saturday. Read More >

Automatically generated image showing areas of convective inhibition.

 

Thumbnail of automatically generated image showing areas of convective inhibition. Thumbnail of automatically generated image showing areas of convective inhibition. Thumbnail of automatically generated image showing areas of convective inhibition.
Hour - 1 Hour - 2 Hour -3

4 Panel Display | Animated Loop

CIN 

The image is a surface based measurement of Convective INhibition (CIN) or what is sometimes more commonly referred to as the strength of the cap.  The value is capped off at 500 J/KG.  In cases where there is no surface based CAPE available this parameter is set to 500 J/KG.

The yellow contours are the Lid Strength Index (LSI).  This is another measure of how strong the cap is.  It shows the thermal difference between a lifted surface parcel and the warmest part of the cap.  Higher values indicate a more stable layer.

In general, the Cap is said to be breakable when CIN is 30 J/Kg or less and/or the LSI is 2 degrees or less.  A negative LSI is rare, but is indicative of freely buoyant low level instability.

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