Comparing All Sky LAP CAPE with RAOBs

One of the forecast problems of the day for the LSX forecast area is determining how far north the reservoir of instability will extend. It may be useful to monitor the all-sky LAP CAPE product in concert with surface obs to assess the destabilization throughout the day. Looking at a comparison of the product with selected 12Z RAOBs, the product appears to have a reasonable representation of CAPE values so far.



The ILX RAOB is in the stable air well north of the warm front:



Although the MLCAPE at SGF is zero, the LAP CAPE produce is indicating around 400 J/kg of CAPE, which appears to reflect the MUCAPE in the sounding:



The LAP CAPE product underestimated the CAPE at LZK, but still gets the general idea:



While some of the details may not be correct, and it is blocky in places, the LAP CAPE product appears to be doing a reasonable job at depicting the reservoir of instability over the southern Plains. By 18Z, it showed the northward spread of instability in concert with the northward advancing warm front:


Ron Dayne