New Sterling discussion, SIAP.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
A strong southern stream mid/upper-level trough over the Mid-South
Friday night quickly moves northeast as it phases into a flat trough
over the OH Valley/Mid-Atlantic on Saturday. At the surface, an
associated area of low pressure develops along the northern Gulf
Coast and very quickly moves across the Southeast states through
Saturday morning. The surface low becomes better organized as it
crosses eastern NC into far southeast VA, where it moves offshore
along the NC/VA border.
Precipitation overspreads the area from southwest to northeast
starting late Friday night into Saturday. Temperatures Friday night
are forecast to be below freezing for most of the area. However,
there is considerable uncertainty to the east of US-15 as easterly
winds advect in a warmer marine airmass and strong WAA ahead of the
surface low help to increase temps along/east of I-95. All that
being said, precipitation is likely to start out as snow west of US-
15 and a rain/snow mix along/east of US-15. As the morning
progresses, areas east of I-95 are most likely to transition to a
cold rain, with steady snow west of US-15, and a mix in between.
Having the surface high well to the north and weak onshore flow
preceding the surface low are not generally favorable for
accumulating snow along I-95. Any chance to see higher snow
totals there will be dependent on higher precip rates and wet
bulb effects overcoming the marginal temperature profile.
Still, p-type is going to be highly sensitive to the track of the
low, with a tight rain-snow gradient likely. Significant snow
accumulations are most likely along/west of the Blue Ridge and
Catoctins. Where precip is more likely to be in the form of rain,
near and east of I-95, there is the potential for instances of
flooding. Continue to monitor the progress of this storm as the
weekend approaches.
The coastal low tracks northeast and away from the area Saturday
night, then a reinforcing upper trough traverses the area on
Sunday. Some lingering rain and snow showers possible during the
first part of Monday north of I-66 and west of the Blue Ridge,
though conditions dry out quickly in the afternoon. Upslope
mountain snow showers continue into Sunday night.