675
FXUS62 KRAH 082110
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
410 PM EST Mon Dec 8 2025

.SYNOPSIS...
A vigorous mid and upper-level disturbance will move across VA and
NC through this evening, then offshore. Arctic high pressure will
follow and build across the region through Tuesday. The high will
settle across the Southeast ahead of a strong, clipper low pressure
system that swing across the Great Lakes Tuesday night and
Wednesday. A moisture-starved cold front trailing the clipper low
will move across NC Wednesday night.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 245 PM Sunday. . .

*A Winter Weather Advisory in effect through 12pm Tuesday for
portions of the northern Piedmont and northern Coastal Plain of
central NC.

*Up to an inch of snow accumulation is possible, highest along the
immediate NC/VA border, with lesser amounts south. Isolated areas
near the VA/NC border could receive up to 2 inches of snow.

*Any leftover moisture on surfaces are expected to freeze Monday
night resulting in areas of black ice Tuesday morning, thus the
extension for the Winter Weather Advisory through noon on Tuesday.

We are currently seeing a rain/snow mix line extending from just
south of Roanoke Rapids down towards Asheboro. Drying has already
begun across the western Piedmont with lingering snow showers across
the Northwest Piedmont. Expect these snow showers to taper off this
afternoon, over the next few hours. For the Triangle region many
surface reports have been mainly rain-snow around the Durham area
with a slow change over expected across the Raleigh/Wake County area
in the next hour or so. Since there is drying aloft and the dry air
within the column is making its way to the surface quickly, I would
not expect a long lived all snow event for the Triangle area but
as mentioned in previous discussions a quick burst of light snow
before the end of the event. If any snow does fall, accumulations
shouldn`t be an issue for the Triangle region as temperatures are
still just above freezing and wet snow flakes are expected to melt
on contact with the warmer surfaces. However motorists should use
extra caution with wet slippery roads this afternoon/evening. To the
north of the Triangle, near the VA border we continue to see snow
coming down with reports from Roxboro and Henderson of light snow
falling across the region with accumulations only occurring on
grassy and elevated surfaces. This band is expected to move across
the northern Piedmont and into the Northern Coastal Plain over the
next few hours, continuing as all snow. Latest model data shows a
slight increase in amounts across the Northern Coastal Plain and
areas along the VA border with this band as rates are expected to
slightly increase the last few hours as it exits the area. All the
precip is expected to exit the western portion of CWA over the next
hour or so, and continue to clear the region through late evening.
Temperatures are expected to crash as the cool dry air moves into
the region with overnight lows in the mid to upper teens across the
north to low/mid 20s US-64 south. As the shortwave exits the area
later this evening, winds are expected to pick up as precip moves
out with gusts up to 25 mph. Winds will calm down before sunrise as
high pressure settles overhead.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 335 PM Monday...

* Arctic cold, and dry

Behind the vigorous shortwave trough that will have moved off the
Middle Atlantic coast by the start of the period, heights aloft will
rise across the Carolinas on Tuesday. Meanwhile, another shortwave
perturbation now over the far nern Pacific, and dominated by shear
vorticity and with model-analyzed upper-level winds of 150-175 kt,
will dig sewd across the nrn Plains, then amplify sharply across the
upr Midwest Tue night. Associated strong subsidence over cntl NC
early Tue will weaken with time, but it will have a lasting dry
influence through the lwr/mid-levels through Tue night. There will,
however, be periods of considerable cirrus and cirrostratus that may
become orographically-enhanced and regionally-maximized over the srn
Middle Atlantic Tue afternoon through early Wed.

At the surface, Arctic high pressure now centered at 1029 mb over MI
will weaken while migrating swd and across the middle Atlantic and
Carolinas Tue, then into nrn FL by 12Z Wed. It will do so downstream
of a clipper low that will deepen into the 980s millibars over MI, 3-
4 sigma below average, by 12Z Wed. After light and variable winds
within the Arctic surface ridge Tue, the MSL pressure gradient will
tighten markedly over cntl NC between the ridge and the anomalously
deep clipper low and favor the development of a swly breeze Tue
night.

After a very cold start to the day, and an icy one where snow
accumulated and/or the ground was adequately soaked by rain (eg. at
least several hundredths of an inch), temperatures will only rise to
afternoon highs in the mid/upr 30s across the nrn Piedmont and nrn
Coastal Plain to lwr-mid 40s elsewhere. Then despite the presence of
the Arctic airmass, the aforementioned developing swly surface wind,
and also high clouds that will probably thicken and lower with time
through Wed morning, will keep overnight lows within a category or
two of climo - mostly mid-upr 20s.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
As of 400 PM Monday...

* Mostly dry, with near average temperatures Wed that will
  transition to well below average by Mon

One polar vortex will rotate across srn QC and adjacent Atlantic
Canada through the end of the week, while another will dig sewd
across the Northwest Territories and cntl Canada. The models
indicate the latter one will reach lower latitudes than the first
and yield 3-4 sigma below average 500 mb heights as it
progresses across and offshore srn New England Sun-Mon.

At the surface, a cold front trailing a clipper low that will lift
across the lwr Great Lakes Wed will move across cntl NC, moisture-
starved and dry east of the Appalachians, Wed night. A modified and
weakening Arctic high will follow and build across the OH Valley and
srn Middle Atlantic through Thu night, during which time another
clipper low will lead a much stronger Arctic high (1040+ mb) across
the Canadian Prairies and nrn Plains. A warm front will precede that
clipper low across the srn Middle Atlantic Fri-Fri night, which will
place cntl NC on Sat between the Arctic front over the OH Valley and
a separate, strengthening frontal zone over the Deep South and
Southeast. Those two fronts are likely to merge over VA/NC on
Sunday, with following strong, Arctic ridging over the Middle
Atlantic through early next week.

The sensible weather related to the pattern described above will
feature moderating and mild temperatures, and with a strong and
gusty swly surface wind, on Wed. Aside from a small chance of rain
along the retreating warm front on Fri, mainly near and north of the
VA border, it will be continued dry and seasonably chilly through at
least the first half of the weekend. The next chance of
precipitation will accompany the merging frontal zones over NC on
Sun, but with lift and precipitation chances that will probably
depart prior to the arrival of the cold air, with associated limited
threat of wintry precipitation. Sun night and Mon then appear just
very cold and dry under the influence of the dominant, Arctic ridge.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
As of 110 PM Monday...

A precipitation shield now blossoming across cntl and ern NC will
include ongoing snow at INT/GSO and a transition to snow at RDU and
RWI in the next couple of hours. While the predominant precipitation
type at FAY will be a cold rain, a mix with snow will be possible
for a few hours around and shortly after sunset. Otherwise, a mix of
IFR-MVFR restrictions in both ceilings and visibility restrictions
will lower a category on average through late this afternoon-early
this evening, lowest and longest at RWI, then gradually lift through
MVFR overnight and scatter to VFR Tue morning. Nely surface winds
will also be at least occasionally gusty, as the MSL pressure
gradient tightens between deepening low pressure off the coast of
the Carolinas and Arctic high pressure that will build south across
the region tonight.

Outlook: VFR. Low-level wind shear will be possible, especially over
the Piedmont, Wed morning, followed by the development of a strong
and gusty swly surface wind with daytime heating/mixing through Wed
afternoon.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 7 AM Monday to noon EST Tuesday for
NCZ007>011-021>028-041>043.

&&

$$

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