129
FXUS62 KRAH 010745
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
245 AM EST Mon Dec 1 2025

.SYNOPSIS...
A cold front will move across central and eastern NC, then offshore,
this morning. Cold high pressure will migrate quickly across and
offshore the Middle Atlantic today and tonight, ahead of low
pressure that will develop and rapidly strengthen from the Southeast
to the Middle Atlantic coast on Tuesday.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 245 AM Monday...

* Dry through the day, with rain chances returning late tonight.

* Below normal high temperatures, with near normal lows.

A cold front will continue to push through central NC overnight,
exiting the region by daybreak this morning. This will allow for
high pressure to pass north of the region through the Great Lakes
region and into the northeast US, setting up another wedge airmass
by afternoon/evening. At the same time, a trough and associated cold
front will start to approach from the west late tonight as a low
pressure system starts to form and moves up the southeast coast.
This will allow for a soaking rain to start spreading into the
region from the west shortly after midnight. The HREF 6 hour local
probability matched mean shows generally 0.15 to 0.75 inches of rain
between 1 and 7am for central NC, with the greater values to the
west. Widespread rain will continue into Tuesday.

High temperatures should be about 10 to 15 degrees below normal this
afternoon. This will equate to highs in the mid 40s north to around
to slightly above 50 in the south. Overnight lows will dip to near
freezing in the north to low 40s in the south. Temperatures look to
be above freezing when and where rain will fall late tonight.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 310 PM Sunday...

Monday will serve as a transitory day, as central NC remains wedged
between the departing system off the eastern seaboard, and a digging
upper trough across central US. Expect cool nely sfc flow via a sfc
high centered over New England with highs reaching the mid 40s to
around 50 in the south.

By late Monday night, the potent upper trough will begin to lift
across the TN Valley/eastern seaboard. Associated mid-level height
falls and anomalous moisture will spill across the Deep
South/southeast.  At the sfc, a low is forecast to develop over the
Gulf and ride north along the I-95 corridor through early to mid
Tuesday afternoon.

These sfc and upper features, along with a deep pool of moisture
will promote a good soaking of rain for us with amounts of 1 to 1.5
inches widely.  Most of the guidance is in good agreement riding the
sfc low through our Coastal Plain, keeping the warm sector along the
coast/to our south.  However, if this tracks slower and further
west, there could be a brief window of high shear/low CAPE overlap
in our far southeast counties. Hodographs are large and curved,
which, in this scenario could promote storm organization.  Think the
chances are limited as of now (better chances down in Georgia), but
we`ll monitor trends as we get into high-res guidance range.

The sfc low and associated rain/moisture will quickly skirt offshore
by late Tuesday afternoon, behind which nwly flow aloft and drying
will persist through 12Z Wednesday.  Overnight lows in the mid to
upper 20s are expected behind the system Tuesday night with some
gusty nwly winds of 20+ mph possible through Wednesday morning.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 350 PM Sunday...

Chilly surface high pressure will build in from the west on
Wednesday, weakening on Thursday. Looking aloft, WSW flow will
largely prevail, with strong mid-level height rises and subsidence
on Wednesday behind the departing shortwave over the Canadian
Maritimes. This will bring cool dry weather on Wednesday and
Thursday, with sunny skies on Wednesday giving way to increasing
clouds on Thursday/Thursday night. Wednesday`s forecast highs are
mid-40s to 50 with lows Wednesday night in the mid-20s to 30.
Thursday will be a bit milder with highs in the 50s, ahead of a dry
cold front that moves through in the afternoon. Lows Thursday night
will be in the mid-20s to lower-30s.

Meanwhile a second stronger Arctic high will move from the Northern
Plains to the Upper MS and OH Valleys. This ~1030 mb high will reach
the northern Mid-Atlantic and New England on Friday, building down
the Eastern Seaboard. The next shortwave will also move from the
Southern Plains into the Eastern US, spreading moisture into central
NC that overruns the cold high pressure wedge. Both the 12z GFS and
ECMWF depict a coastal low that moves NE from the northern Gulf
Coast early Friday to along the coast of the Carolinas on Friday
night. All of this results in fairly high confidence for
precipitation over central NC on Friday and Saturday, and ensemble
means depict half an inch to an inch of QPF. The exact timing and
length of the event are unclear, particularly among the ensemble
members which differ on the start time. Furthermore, the ECMWF
depicts a slower moving and deeper shortwave that provides
additional forcing for precipitation into Saturday, while the GFS
and CMC dry us out by then. POPs increase to chance on Friday,
highest (likely to categorical) on Friday night, decreasing to
chance again on Saturday and Saturday night.

Given the cold high building down from the north, some frozen
precipitation will be possible over the Piedmont at the start, but
confidence is very low on details this far out. With southerly flow
aloft quickly advecting in warmer air and a wedge of cold air
remaining near the surface, this would suggest more of an ice threat
vs snow. One limiting factor is the progressive nature of the
pattern, allowing for the high to move east into the Atlantic. So if
there is any frozen precipitation, an eventual changeover to plain
rain everywhere is likely. The deterministic GFS is especially cold
and less transient with the high, but it is an outlier even compared
to its own ensembles. Even still, ECMWF and GFS deterministic and
ensemble guidance have trended a bit colder overall, so it certainly
warrants watching. Given the spread in guidance and that this is
Days 6-7, confidence is low in precipitation type and is certainly
subject to change. Continue to follow the forecast for the latest
updates.

Temperature forecast confidence decreases substantially by Friday as
the model spread increases. A lot will depend on the timing and
placement of the cold high to the north, as well as the coastal low.
But Friday looks to be a very chilly day, even if it is just cold
rain, with highs in the 30s and 40s. Forecast highs this weekend
range from upper-40s to upper-50s. Lows will generally be in the 30s.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
As of 110 AM Monday...

The 06Z observations are showing that much of the region`s ceilings
have returned to VFR as the light rain continues to move eastward
out of central NC. The trailing cold front is also on the doorstep
of the NW Piedmont. Once the front moves through, VFR conditions
should prevail everywhere for much of the 24 hour TAF period. Ahead
of the front and the associated dry air, a few areas may see some
patchy fog develop over the next few hours. A few locations in the
southeast are showing lowered visibilities, but confidence is too
low to include at any TAF sites. Additionally, occasional gusts will
be possible overnight and through the morning with the frontal
passage. The best chance for more frequent and stronger gusts looks
to be in the east, where the wedge airmass did not reach or is not
as deep. Winds overnight and through the day should veer from
northwesterly to easterly. The next round of sub-VFR ceilings look
to hold off until around 06Z Tuesday.

Outlook: Another storm system will bring widespread rain and IFR or
lower conditions late Mon night through Tue. VFR returns Wed and Thu
under high pressure. Another late-week system may bring rain/showers
late Fri-Sat.

&&

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

&&

$$

SYNOPSIS...MWS
NEAR TERM...LH
SHORT TERM...Luchetti
LONG TERM...Danco
AVIATION...LH/AK