Snippet from AFD from Mt Holly. Pretty informative even if we don't see direct impacts from the upcoming coastal storm inland.
The very cold temperatures and bitter wind chills will persist
the remainder of the week and beyond. This will occur due to a
deep upper level trough centered over Eastern Canada with
repeated re-enforcing shots of arctic air swinging in from the
north and west around this feature. For Wednesday night through
Saturday, expect morning low temperatures in the single digits
to negative single digits with each morning actually looking
slightly colder than the previous one due to these re-enforcing
shots of arctic air. More importantly, there will be at least
some winds through most of this period with early morning wind
chills still expected to be sub-zero region wide with negative
teens N/W of the I-95 corridor to even around -20 in the
southern Poconos. Some moderation in temperatures may occur
Sunday into early next week however temperatures still look to
be well below average.
Overall, it is exceedingly rare to get this combination of length
and magnitude of an arctic airmass for this area and it should be
taken seriously for those who have to venture out in the cold for
extended periods of time.
KEY MESSAGE 2...A rapidly deepening storm will develop off the
east coast this weekend. While confidence in specific forecast
details remains low, the storm could bring at least portions of
the area moderate to significant impacts from snow, strong
winds, and coastal flooding.
Forecast models continue to forecast cyclogensis occurring
beginning Saturday off the southeast coast with rapidly
deepening low pressure depicted to then move north and east
Saturday night through Sunday. This will occur due to a potent
upper level disturbance pivoting around the base of the long
wave trough over the east interacting with the strong baroclinic
zone along the coast.
In terms of impacts to our forecast area, this still hinges on the
exact track the storm takes which remains uncertain at this time.
The latest GFS trended west some and is overall not too
different than the GEM. The latest EC is still farther east than
these models. It is also worth noting that there continues to
be spread in the GFS ensemble members (the GEFS) with the
ensemble mean a bit farther east than the deterministic . So
this all said, it boils down to whether the storm tracks farther
northward along the coast before turning east (bringing the
area greater impacts) vs. being quicker to turn east meaning the
track would stay farther away bringing more limited impacts.
Potential impacts include not just heavy precipitation but also
strong winds and coastal flooding as the storm will have a tight
pressure gradient with a very strong wind field.
