465
FXUS62 KRAH 030826
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
426 AM EDT Thu Apr 3 2025

.SYNOPSIS...
A front will remain quasi-stationary over the western Carolinas
tonight, then dissipate on Thursday. Unseasonably strong and warm,
sub-tropical high pressure will otherwise extend westward across the
South Atlantic states through Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 836 PM Wednesday...

Overview: Early evening radar and satellite imagery reveals abundant
cloud cover across much of NC, with a few showers and isolated non-
severe storms moving through the western Piedmont. The showers
developed following the passage of a warm front that has mostly made
it through the forecast area as of 00Z...with the only site
remaining on the cool/stable side of the front being INT with a
dewpoint of 51 whereas all other sites have dewpoints in the upper
50s to mid 60s. This is all setting the stage for a cloudy/mild
night tonight.

Precip chances: PoPs will be maintained across the western Piedmont
through the remainder of the evening hours with a mention of showers
and thunderstorms mainly from the Triad south to the SC state line.
Several consecutive runs of the HRRR and other hi-res models insist
that these showers will maintain themselves as they move northward.
Instability is forecast to increase a bit through midnight per SPC
mesoanalysis page, but a lack of strong forcing should keep them
below severe thresholds. Eventually after midnight the BL should
stabilize and these showers should dissipate, but quickly be
replaced by areas of drizzle as strengthening isentropic ascent
overspreads much of NC tonight. Drizzle may be seen as far east as
the Triangle before daybreak, and a 15-20 percent mention of precip
will be maintained in these areas as well.

Temperatures: Expect lows to range from the low/mid 60s in the
north, to the upper 60s in the south. It`s entirely conceivable that
a few spots in the southern Coastal Plain may stay above 70 tonight.
See climate records section below, including record warm minimum
temperatures which could be jeopardized tomorrow morning.

&&

.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
As of 205 PM Wednesday...

* Thursday will begin a stretch of anomalously warm conditions with
  little overnight relief.

Widespread low overcast, and perhaps some light drizzle, Thur
morning will gradually lift/scatter from southeast to northwest
through the morning into the early afternoon.

Continued strengthening/expanding of the anomalous sub-tropical
ridge over the southwest N. Atlantic, scattering cloud cover, and
12z low-level thicknesses 40m above normal for early April, will
result in the first of several days of abnormal heat for central NC
as temperatures rise into the upper 70s to mid/upper 80s. Warmest
temps will likely be across the Sandhills into the eastern Piedmont
and Coastal Plain where erosion low overcast occurs first.

In the wake of the low overcast, diurnal heating of the already
warm/moist airmass in place will result in moderate instability
(1000-2000 J/kg of MLCAPE) mainly over the Piedmont. Proximity to
the strong sub-tropical ridge may prevent much or even any deep
convection, but isolated showers will be possible during the
afternoon into the early evening hours. Among the latest 12z Hi-Res
guidance, only the HRRR develops any deeper convection, likely since
it has surface dew points closer to 70 degrees while mean 12z HREF
dew points are closer to mid 60s during the afternoon. Light
stirring southwesterly flow and potential redevelopment of some low
overcast will result in another unseasonably warm night as
temperatures only dip into the mid 60s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 420 AM Thursday...

The weather pattern across central NC on Saturday will continue to
be controlled by a subtropical high aloft that remains anchored east
of FL and ridges up the Eastern Seaboard for one more day. Meanwhile
a 1025-1030 mb surface high centered east of GA/SC and SW of Bermuda
will slowly drift east. A cold front initially extended from eastern
TX to the mid-MS Valley and Lower Great Lakes early Saturday will
reach the TN Valley and northern Mid-Atlantic by early Sunday, as a
wave of low pressure associated with a mid-level shortwave over the
Southern Plains rides along the front. This will help to push Friday
evening`s backdoor front well to our north, and with high pressure
to our SE resulting in capping/subsidence aloft, Saturday looks dry
and partly to mostly sunny. High temperatures will again be quite
warm, mainly in the upper-80s to lower-90s, which is 15-20 degrees
above normal and near the daily record highs for April 5 at GSO, RDU
and FAY. Skies will turn mostly cloudy on Saturday night, and with
southerly flow ahead of the approaching cold front, lows will be
very warm and near record high minimums, only dropping to the mid-to-
upper-60s.

The Bermuda high will finally begin to break down and shift away
from us on Sunday, in response to the mid-level southern stream wave
pushing east and a broad northern stream trough digging into the
Great Lakes. This will help push the cold front east through our
region, as a wave of low pressure tracks along it. The frontal
passage looks slow due to the SW flow aloft, and while the GFS is a
bit faster than the ECMWF, both models are in pretty good agreement
that it will gradually move east across central NC Sunday night into
Monday, maybe even stalling out for a time. So continue likely to
categorical POPs from Sunday afternoon into Monday. Precipitation
may not completely clear our far SE until late Monday night if the
ECMWF and many of its ensembles are correct. Some storms can`t be
ruled out on Sunday and Monday, but at this time instability looks
marginal, with CAPE on the ECMWF and GFS generally less than 500
J/kg, and their ensembles depicting very low probabilities of
exceeding that. So despite strong winds aloft, the severe threat
looks fairly limited at this time. Even outside of convection, GFS
point soundings on BUFKIT indicate gusts of 25-35 mph will be
possible during the day on Sunday. The bigger threat at this time
looks to be heavy rain, and WPC has our region in a marginal (level
1 of 4) risk of excessive rainfall on Sunday/Sunday night, which
lingers in our far SE on Monday. WPC total QPF for the event is in
the 1-2 inch range, but the deterministic ECMWF and GFS both have
stripes of 2-3 inches across a portion of central NC, and the 90th
percentile QPF of their ensembles is in a similar range, indicating
potential for isolated totals that high especially where any storms
train. At the same time, this would provide some welcome drought
relief as much of central NC is currently in D0 or D1 conditions.
Sunday looks a bit cooler from cloud cover and precipitation
chances, but still very warm with highs in the mid-80s to 90, which
could still approach some records. Sunday night`s lows will again be
quite mild (upper-50s to mid-60s) before we turn much cooler and
close to normal on Monday (highs mid-60s to lower-70s, lows in the
40s).

We finally dry out on Tuesday and skies turn sunny, as Canadian high
pressure builds in from the NW and westerly flow aloft around the
mid/upper low over the Great Lakes and New England pushes the cold
front well to our east. A reinforcing cold front on Tuesday will
bring a shot of even cooler, drier air with highs both Tuesday and
Wednesday only in the upper-50s to mid-60s and dew points in the
teens and 20s. As the surface high settles near the Appalachians on
Tuesday night, went on the cooler side of guidance for temperatures
as decent radiational cooling conditions and 1000-850 mb thicknesses
only in the 1280-1295 m range will support widespread lows in the
lower-to-mid-30s. Upper-20s will even be possible in outlying areas.
This will result in some frost and freeze concerns.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 205 AM Thursday...

Widespread MVFR ceilings throughout cntl NC at 06Z may lower to IFR
for a short time later this morning and be accompanied by periods of
light rain and drizzle especially over the Piedmont in the few hours
centered around 12Z. Ceilings should then gradually lift and/or
scatter to VFR at FAY, RWI, RDU by early this afternoon, while IFR-
MVFR ceilings will be slower to lift and disperse, likely not until
mid to late afternoon, at GSO/INT. Sswly surface winds will
strengthen and become frequently gusty to 20-25 kts by ~12-13, then
remain so until diminishing around sunset. The exception may be at
FAY, where an inland-moving sea breeze may maintain a little sly to
ssely gustiness there until ~02-03Z this evening.

Outlook: IFR-MVFR ceilings will likely redevelop Fri morning and
again Sat morning, amid continued unseasonably moist/humid low-level
flow. A strong cold front will be accompanied by a band of
convection and flight restrictions, as it moves slowly east across
cntl NC Sun night and Mon, possibly as early as late Sun afternoon
at INT/GSO.

&&

.CLIMATE...

Record High Temperatures:

April 3:
KRDU: 91/1967
KFAY: 90/1934

April 4:
KGSO: 86/1934
KRDU: 88/1934
KFAY: 93/1910

April 5:
KGSO: 87/1942
KRDU: 90/1942
KFAY: 91/1942

April 6:
KGSO: 89/2010
KRDU: 93/1967
KFAY: 91/2010


Record High Minimum Temperatures:

April 3:
KGSO: 64/1946
KRDU: 62/2000
KFAY: 65/1977

April 4:
KGSO: 62/1999
KRDU: 63/2017
KFAY: 63/2017

April 5:
KGSO: 60/2023
KRDU: 64/1910
KFAY: 64/2008

April 6:
KGSO: 65/2023
KRDU: 69/2023
KFAY: 69/2023

&&

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

&&

$$
SYNOPSIS...MWS
NEAR TERM...Leins
SHORT TERM...Swiggett
LONG TERM...Danco
AVIATION...MWS
CLIMATE...NWS