Nearcasting CAPE vs Visible Imagery

The Nearcasting model is an excellent observation-based decision-support product that has been developed by UW-CIMSS.  One of the product's strengths is to forecast where instability is and is not located.  The image below is a 7-h forecast of Nearcasting CAPE (valid at 1900 UTC) with the 1900 UTC Visible imagery and previous hour's lightning observations.  Unstable air is in shades of blue and purple while stable air is in shades of green and brown with the CAPE and Visible images transparent for ease of comparison.

Some things to take away from this figure.

1. The majority of the CU field and convection is to the south of a large-scale midlevel instability gradient that extends from central AR east northeastward into the Mid-Atlantic states.

2. The deeper convection is aligned well with the deeper blues and purples (higher values of CAPE) across northern MS and most of TN, eastern Gulf of Mexico, and across central FL.

3. The most stable air extends from southern MO east northeastward into the eastern Great Lakes and into New England...notice there are very few clouds in this area.

Not only is this product good on the NWS CWA level but also for the analysis of large-scale areas of convection (and lack of convection) that are important for operations at the Storm Prediction Center and the Aviation Weather Center.  The SPC could use the Nearcasting model to assist in their forecasts of the "thunder line" and the AWC could use the output to assist their partners with highlighting which high altitude jet routes are clear for the day (e.g., the NYC to Chicago corridor today).