Area Forecast Discussion
National Weather Service Columbia SC
619 AM EST Sun Dec 24 2017
There is reasonable confidence that a broad mean trough will be
over much of the eastern part of the country during this period
but uncertainty exists regarding shortwave energy moving
through the trough. Thermal trends in the models continue to be
colder with a cold air damming wedge likely developing on
Thursday as polar arctic air filters into the area from a 1042mb
high over southeast Canada and New England. This will set the
stage for potential wintry weather across parts of the forecast
area with highest confidence along and north of the I-20
corridor Thursday night into Friday.
The GFS has struggled with run to run consistency and the 00z
run shows shortwave energy moving through the mean flow bringing
precipitation Thurs and Thursday night but quickly shifts east
early Friday with rising 500mb heights. The ECWMF on the other
hand is a bit deeper with a digging upper trough keeping
moisture transport over the area longer and developing a much
deeper low off the coast.
Lowered temperatures Wednesday night through Friday across the
board with the expectation that a strong CAD regime will
develop. Hopefully we will see some convergence among the models
regarding precipitation late in the week as well as thermal
profiles to increase confidence in the forecast.
