104
FXUS62 KRAH 020916
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
415 AM EST Tue Dec 2 2025

.SYNOPSIS...
An in-situ cold air damming ridge will extend across the Carolinas
and Virginia today, while coastal low pressure will rapidly
strengthen while tracking along the East Coast. Cold high pressure
will follow and migrate across the Southeast, while modifying,
through Thursday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 400 AM Tuesday...

* A cold, soaking rain early today will yield to west to east drying
  and clearing from late afternoon through evening.

A positively-tilted shortwave trough stretching this morning through
a couple of perturbations over wrn MO and the srn High Plains will
lift across and offshore the Middle Atlantic and Carolinas through
this evening, then offshore overnight. Downstream of that trough,
intense low through mid-level WAA now centered squarely over the
Carolinas will both provide strong ascent and transport of a plume
of 1.5" and ~200 % of normal PWs across and offshore the Carolinas
and srn Middle Atlantic through this afternoon.

At the surface, the center of a weakening, 1027 mb, Arctic high now
centered over ME will progress quickly ewd and offshore. An in-situ
cold damming ridge will be left behind the transitory and weakening
high and across the favored cold air damming region across the
Carolinas and neighboring VA and GA today. Meanwhile, a pair of
deepening lows now centered at 1008 mb over the nern Gulf and at
1011 mb just off the cntl SC coast, respectively, will consolidate
and rapidly deepen while tracking along and just offshore the
Atlantic coast, to around 985 mb near the srn Nova Scotia coast by
12Z Wed. Through the same time, continental Polar high pressure now
centered at 1022 mb and with unseasonably cold temperatures over the
srn Plains, will progress ewd and into the OH and TN Valleys, with
associated cold and dry air advection that will spread east of the
Appalachians and across cntl NC from late this afternoon through
tonight.

A large, mainly stratiform precipitation shield accompanying the
aforementioned, intense WAA now overspreading cntl NC will serve to
lock in an in-situ cold air damming airmass, when temperatures
throughout the morning will be near steady in the mid 30s to lwr
40s. As the WAA regime and deep moist axis depart by early to mid
afternoon, so too will the rain shield, with following downslope
flow and CAA in the stable in-situ CAD layer. As such, west to east
erosion of the CAD airmass should result during the afternoon and
evening, which should allow for some temperature recovery into the
40s, most strongly over the srn Piedmont. Skies will further clear
overnight, with light nwly stirring becoming calm in many areas by
sunrise, and with low temperatures in the mid 20s to lwr 30s.

&&

.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
As of 330 AM Tuesday...

* Clear or mainly so, and unseasonably cold

Strengthening, quasi-zonal flow will prevail across the Southeast
and Carolinas this period, downstream of an elongated, positive tilt
trough that will extend from a strongly-amplifying shortwave over ON
and the upr Great Lakes wswwd to another major shortwave over the
srn Rockies and Southwest. Within that regime, strongly rising
heights and strong and deep subsidence over cntl NC early Wed will
tend toward weakly falling ones by Thu morning, with the latter
supportive of the maintenance of both altocumulus and cirrostratus
ceilings into cntl NC just beyond this period (ie. through the day
Thu).

At the surface, continental Polar high pressure, now centered at
1022 mb and with unseasonably cold temperatures over the srn Plains,
will progress ewd and across the Southeast through early Thu.

The sensible weather over cntl NC related to the pattern described
above will feature a sunny or mostly so Wed, with ~10 F below
average high temperatures mostly in the mid-upr 40s, except lwr 50s
across srn counties. Wed night should be equally as clear, or mostly
so, and cold, with low temperatures mostly in the mid-upr 20s,
except around 30 F in urban areas.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
As of 230 AM Tuesday...

* Highest chances for precipitation still Friday and Friday night,
  with lower confidence in chances Saturday through Monday.

Aloft, a s/w will track ewd from the Four Corners, across the srn
Plains and lwr/mid MS Valley on Thu/Thu night, then continue ewd
across the srn Appalachians and Carolinas on Fri. Meanwhile, the
longwave trough will remain over the Plains/Intermountain West
Thu/Thu night, as yet another s/w drops sewd from sw Canada to the
cntl Plains. This s/w may finally help the longwave trough progress
ewd across the cntl and ern CONUS Fri night through Sat night.
Central NC should be under the influence of wswly to swly flow
through at least Sat. A trailing s/w may move across the region Sun
or Mon, but model variability increases over the weekend into early
next week. At the surface, a dry cold front will move southward
across the area on Thu, with Arctic high pressure ridging swd into
the area as it moves ewd from the Midwest across the OH Valley and
into the Northeast US Thu night. Meanwhile, an area of low pressure
will develop over the NW Gulf Thu night, then eject newd across the
Southeast US and off the Carolina coast Fri/Fri night. The biggest
difference between the operational runs of the GFS and EC is the
strength and track of the Arctic high, which could impact
temperatures and perhaps p-types across the NW Piedmont. The low
should continue to move away from the area and out over the Atlantic
Sat/Sat night, with high pressure moving across the region in its
wake. The next low pressure system should develop over the cntl
Plains/mid-MS Valley Sat or Sat night, tracking across the region
Sun or Mon, though timing varies amongst the models.

Precipitation: Thu should generally be dry, with precipitation
expected to spread enewd across the area Thu night/Fri morning,
lingering through Fri night. While the operational EC and GFS both
generally dry out by Sat night (GFS earlier than EC), there is still
enough spread in the ensembles to hold on to slight chance through
Sat night/Sun morning. Precipitation should largely be rain, however
there is a chance for some wintry precipitation to mix in at the
beginning and possibly the end of the event. For now, confidence and
impacts remain low. Additional precipitation is possible with the
trailing s/w either Sun or Mon, but given the significant difference
in timing, will keep chances below slight for now.

Temperatures: Thu should be the warmest day of the extended period,
with highs ranging from around 50 degrees across the north to mid
50s south/SE. Low confidence in temperatures Thu night through Fri
night, as they will depend on the strength and position of the
Arctic high, track and strength of the low, and the associated
precipitation. Highs will remain below normal Fri-Mon, lowest on
Fri. Lows should generally remain near to slightly below normal,
generally ranging from mid/upper 20s to low/mid 30s.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
As of 135 AM Tuesday...

MVFR ceilings now over cntl NC will lower into LIFR-IFR range, as a
large shield of stratiform rain overspreads the region and becomes
moderate to heavy at times through midday or early afternoon, before
tapering off. As the rain departs, ceilings will gradually lift
through IFR-MVFR and ultimately scatter to VFR late this afternoon
or evening. Skies will then become clear overnight, as cold and dry
high pressure builds in from the west.

Outlook: Another storm system will bring a risk of flight
restrictions and rain, the latter of which may begin as a short
period of snow over the Piedmont, Fri-Sat.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...10
AVIATION...MWS