LWX AFD from this morning
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Uncertainty remains in the track of the coastal low pressure system
poised to move north Friday and into this weekend. Confidence is
increasing in a potential impactful event for the majority of the
Mid-Atlantic coast and further across New England. A deep, digging
trough will move eastward Friday into Saturday. This, coupled with
the surface low will bring the threat for impactful snow to most of
the area.
To start with, by late Thursday night a period of upslope snow
showers should begin for the Allegheny Front as the upper trough
begins to move further east. At this point, it is increasingly
likely that the Allegheny Front will see a prolonged snowfall
through late Friday given the upper level low and however the
surface low influences that portion of the area. The snow will
continue to track further east throughout the day Friday and totals
will be greatly impacted by the position and timing of the coastal
low and the upper level low.
There continues to be discontinuity in the exact position of a
coastal low set to form near the Carolinas. Latest ensemble means
for the position of the low remain in disagreement in terms of
timing and intensity. Snowfall totals for the 00z EPS show a more
bullish approach with a closer low track vs the 00z GEFS (3-5"
difference across portions of southern MD). Deterministic guidance
continues to show most of the higher totals across the Delmarva
Peninsula and further north-east. Should the track move further
west, then areas like southern MD and the I-95 corridor may see
significant changes in potential impacts and snowfall totals.
Guidance will continue to zero in on a potential track over the next
few days. To summarize, confidence is high on an accumulating
snowfall across most of the area but remains low with regards to
totals, especially the I-95 corridor and southern MD.
Another important component of this system will be the gusty winds
with a tightening gradient ahead of the system falling into place.
The increased winds and falling temperatures will most likely
warrant Wind Chill Watches/Warnings/Advisories Saturday into Sunday.
Temperatures will most likely fail to reach 30F during this time
period with wind chills in the negatives (-15 to -20 across portions
of the Allegheny Front) during the night.
