668
FXUS62 KRAH 031343
AFDRAH

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

.SYNOPSIS...
A warm front will dissipate over the western Carolinas and central
VA by this afternoon. 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 940 AM Thursday...

No major changes with the morning update. As of the 12Z surface
analysis, the wedge front has retreated to northwest of the Triad,
with sly to sswly flow across all of central NC.

Previous discussion (as of 425 AM): A sub-tropical high over the
swrn N. Atlantic will continue to strengthen and remain the dominant
feature and influence for cntl NC. Surrounding anticyclonic flow
will extend throughout the South Atlantic states.

Unseasonably strong and warm, sub-tropical high pressure that will
extend from near and south of Bermuda wwd and throughout much of the
Southeast, including all of cntl NC. A separate differential heating
boundary/zone will also likely develop and retreat across cntl NC
today, with a southeast to northwest erosion of the now widespread,
mostly MVFR stratus, and with associated cloudy or mostly so
conditions that will linger longest and into early to mid-afternoon
over the nw Piedmont.

Temperatures throughout cntl NC will warm mostly into the 80s and
well above average (~ +15F), except upr 70s possible where the
aforementioned low clouds take longest to erode. After patchy light
rain and drizzle through mid-morning, a few showers and storms will
be possible in the vicinity of the differential heating zone as it
retreats across the srn and nwrn NC Piedmont. The airmass there will
moderately destabilize with diurnal heating of the unseasonably
moist airmass characterized by mid/upr 60s F surface dewpoints,
beneath a plume of modestly steep lapse rates (~6.5 C/km)
accompanying a remnant, contaminated EML plume around the periphery
of the sub-tropical ridge. Unseasonably muggy conditions, with lows
in the mid-upr 60s, will follow tonight, with likely late
redevelopment of low overcast by Fri morning.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 445 AM Thursday...

Hot, sub-tropical ridging at the surface and aloft will continue to
extend across the South Atlantic states. A backdoor cold front may
dip to near the VA/NC Fri evening, then retreat nwd across s-cntl VA
Fri night.

Shallower/thinner than recent days stratus Fri morning will favor a
quicker cloud erosion and following longer and stronger diurnal
heating. As such, temperatures will warm mostly into the upr 80s
throughout cntl NC, to around 90 F in the typically hotter locations
from FAY and AFP to RDU. That stronger heating and associated deeper
mixing will likely cause surface dewpoints to mix out into the lwr
60s, via vertical advection of drier air aloft, so heat index values
will be comparable to ambient air temperatures.

The FV3 is alone in depicting any convection over cntl NC on Fri,
and even that just an isolated cell over the srn Piedmont. Given
continued influence from the sub-tropical ridge as it strengthens
perhaps another decameter, and a lack of a low-level forcing
mechanism, the forecast will remain dry Fri. A slight chance of an
evening storm will exist near the Roanoke River, however, when the
aforementioned backdoor front makes its closest approach to cntl NC.
Low temperatures, with late night stratus possible, are expected to
be mostly in 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 /10Z THURSDAY THROUGH MONDAY/...
As of 620 AM Thursday...

Widespread MVFR ceilings throughout cntl NC this morning may lower
to IFR and be accompanied by light rain or drizzle mainly at INT/GSO
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. IFR-MVFR
ceilings will likely redevelop Fri morning, amid continued
unseasonably moist/humid low-level flow.

Outlook: IFR-MVFR ceilings will probably redevelop 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...KC/MWS
SHORT TERM...MWS
LONG TERM...Danco
AVIATION...MWS
CLIMATE...NWS