RAH Afternoon AFD
With the cold front well to the south of the NC/SC border Thursday,
central NC will remain under the influence of cold high pressure
ridging southward into the region advecting cold air in from the
north. This front is expected to remain south of the area as a
coastal low develops off the SC coast Thursday aft/eve in response
to an upper level shortwave. The proximity of this low to the NC
coast and how much/far moisture extends to the NW will be the
determining factor for how much snow will fall and accumulate. The
wetter NAM/GFS solutions may be a bit too aggressive with the
precipitation extending into central NC, while the much drier ECMWF
solution may be more reasonable. Precipitation should start as rain,
moving into the south during the aft/eve, which will help cool
temperatures to the wetbulb values in the 30-32 degree range by
Thursday night. There will likely be a period of rain mixed with
snow, with little accumulation expected during that time. The best
chance for snow accumulation will be if and where there is a
transition to all snow. Regardless, there will likely be a "sweet
spot" across eastern NC where snow could accumulate to more than an
inch or two and a very tight gradient of snow amounts across the
area. Given the uncertainty, will keep expected snowfall
accumulations below warning criteria at this time, though still have
about 1-2 inches in the Coastal Plain. Highs on Thursday will top
out in the 40s, quickly lowering into the low 30s as rainfall
occurs.