Raw, wet, and chilly to begin the work week

Welcome to March, a transitional weather period. Average daily high temperatures begin the month in the mid-50s, climbing to the mid- and upper 60s by the end of the month. That change isn't a smooth one, with ups and downs in temperatures pretty much the norm. A perfect example is the plunge from Sunday's highs in the low 70s to today's (Monday's) forecast high near the 40º mark.

Another cold air damming (CAD) wedge is responsible for this particular rollercoaster. This graphic from the National Weather Service office in Sterling Virginia illustrates:

A thin layer of dense cold air at the surface is "wedged" across the Piedmont east of the mountains, forced southward by high pressure currently centered across New England. Warm moist air - being lighter and less dense -  is being pushed up and over the CAD wedge, creating clouds and precipitation. 

As of the most recent forecast model runs the precipitation from this setup will begin across Mecklenburg county as rain just after the lunch hour today. Although there could be a few cases of "fuzzy rain" with snowflakes mixing in, today's precipitation will be liquid instead of frozen. Rain will continue through the overnight hours, gradually tapering off Tuesday morning.

The wedge will slowly dissipate tomorrow. The official NWS forecast is for a mid-50s high temperature Tuesday afternoon. However, one forecast model which is particularly good at sniffing out CAD behavior indicates that the upper 40s may be all that can be expected tomorrow. Regardless, expect mostly cloudy skies until late tomorrow afternoon.

By Wednesday the temperature rollercoaster will be on the upswing. The latter part of the work week will see the 70s and perhaps the 80s(!) as warmer air reasserts itself across the region.