Today, we were in the Pendleton, OR CWA, for a Marginal Risk from SPC. The main feature to focus on were 500 mb vorticity maxima moving northwest into the region during the afternoon. This would combine with cold temperatures aloft to product ample MUCAPE. Deep layer shear was relatively strong (40 to 50 knots) in the eastern portions of the area, weaker to the west.
The LAP products provided good estimates of CAPE during the afternoon, when sampled with the cloudy sky data. There were not many locations that had this, but was inferred to be over most of the area with the modified NUCAPS soundings. Using these products together helped gain confidence in the amount of CAPE over the area.
The GOES winds also helped with estimating the deep layer (700 mb to 250 mb) shear over the area, as the afternoon evolved. This was handy to assess the environment and storm mode.
The CI product was helpful with showing CI potential, despite middle to high clouds blocking some areas. The CI values were low in these areas, but would have been much higher had there not been any middle to high clouds. Using the 1-minute SRSOR imagery to watch the cumulus development, and radar to confirm cell development, these low CI values were a clue that initiation was likely.
I did not get a chance to use Prob Severe and lightning jump much, as the convection was not strong. Some cells had enough lightning flash rates to bring the Prob Severe values to 30%, but they would weaken within a few radar volume scans. No lightning jumps were detected.
JJW
