National Weather Service United States Department of Commerce

Significant Severe Weather and Life Threatening Flash Flooding

A powerful spring storm continues across the country with multiple high impacts in the forecast. Life-threatening, catastrophic, and potentially historic flash flood event continues across the Lower Ohio Valley and Mid-South. A couple rounds of significant severe weather expected from the Mid-South through the Ozarks and ArkLaTex with very large hail and strong tornadoes possible. 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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