Thursday EWP - Start in Rayleigh and Blacksburg CWA

For Thursday, the two EWP groups have begun operations in the Rayleigh and Blacksburg CWA's.

The LAP products depict instability increasing across the region, capturing the sharp cutoff along a frontal boundary draped along eastern North Carolina/Virginia border.The GFS seems to be a little week with instability (compared to adjusted RAOBs and SPC mesoanalysis). These are the gray areas in the LAP retreival type (upper right). Where the LAP algorithm computes retreivals (clear sky or cloudy sky; using GFS as a first guess), it brings the instability up in line with what the other sources have.

 

The LAP Layer PW fields show dry air moving in aloft, with low-level moistening south of of the boundary.

 

Convective initiation had begun in the region around 1800 UTC as depicted in the 1-min VIS.