Today was a day that had weak CAPE (less than 500 J/kg) and modest deep layer shear across the Memphis CWA. A pre-frontal trough slide southward through the area and brought a broken line of showers and some thunderstorms. The storms were relatively weak and did not last too long.
The CI product seemed to pick out some cells that developed into 35 dBZ-plus echoes across portions of the Memphis CWA. The threshold for development seemed to be above 35%, which was lower than the past few days. The convection was relatively low topped, with low freezing levels, so this may have been why CI values above 35% had a good chance of developing. That being said, there were some cells that exceeded 35% that did not develop. Still, the CI product seemed to help deliniate the cells that had a good chance to develop.
The LAP layer PW and CAPE products were helpful with evaluating the environment near the showers and storms today. They gave some confidence that cells may develop south of the advancing pre-frontal trough. In addition, the gradients of the total and 700-300mb PW helped focus areas to watch for future convective development. These products were helpful.
The NUCAPS soundings, once adjusted in the low levels for realistic values, seemed to show representative CAPE and 0C/-20C level values in areas a little southeast of the Memphis area. After comparing to some 12 UTC soundings from representative areas, the NUCAPS values were useful to assess the environment ahead of the showers and storms.
JJW
No comments:
Post a Comment