Tuesday, January 14, 2020

Some weather concerns for Thursday, Jan 16 2020!

Thursday will be cooler behind a cold front combined with clouds overhead. Expect highs from the upper 30's N to the mid 40's S.

The NWS was concerned about wintry precipitation chances Thursday night into Friday morning. Surface ridging shifts east while a shortwave trough and associated surface trough moves into the western Plains. This will lead to warm air advection over a shallow cold layer. The questions are: How warm is that warm nose, how cold is the near surface cold layer, and how much precipitation will actually fall?

Most models agree that the near surface cold layer will be near or below freezing over much of the area after evaporative cooling takes place. There is some disagreement in the extent and timing of the warm nose. Precipitation may start as snow and change to freezing rain later Thursday night or Friday morning, then switch to rain as surface temperatures increase later Friday morning. For now have gone middle of the road with consensus guidance for that warm nose, which gives some freezing rain and snow snow over the eastern half of the CWA (surface temperatures are currently forecast to be a bit too warm for freezing rain over the western half, but that will need to be fine tuned). While still a bit far out, it is helpful to look as some ensemble spread in amounts for a general overview.

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