Latest disco:
Models continue to advertise the possibility of a winter storm on
Friday, particularly for locations north of I-66/U.S. 50. A
preponderance of the 12Z guidance favor an area from I-70 northward
across the Mason-Dixon Line into Pennsylvania. The setup is
certainly favorable for a wintry mix dominated by freezing rain and
sleet. Canadian high pressure builds over Quebec while a stationary
boundary arcs west to east across the Carolinas. The resultant cold-
air damming (CAD) signature is quite favorable to such setups. Low-
level cold air becomes locked in place while warm advection above
this layer ushers in milder air aloft into the (925-850 mb layer).
Models are also hinting at some snow toward northern Maryland given
colder thermodynamic profiles. All and all, travelers will need to
consider this potential winter storm in their plans for Friday.
Aside from this precipitation threat, it will be a chilly day across
the region with highs in the 30s to low 40s (40s along the
Alleghenies).