851
FXUS62 KRAH 020631
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
230 AM EDT Thu May 2 2024

.SYNOPSIS...
Deep high pressure will build over the Carolinas and Southeast
states through Friday, resulting in very warm temperatures. A series
of weak upper level disturbances will move through the region Friday
evening through Sunday, bringing periods of unsettled weather.

&&

.NEAR TERM /TODAY THROUGH TONIGHT/...
As of 135 AM Thursday...

Only cosmetic changes needed to today`s forecast. Still expect
patchy to areas of fog to develop over the Coastal Plain early this
morning, in an area that saw ground-wetting showers/storms yesterday
and where dewpoint depressions are lower. The latest surface
analysis shows a very diffuse pressure pattern over the region, with
weak ridging to our W and E and a very weak and subtle low level
trough between, more evident at 925-850 mb, separating dewpoints in
the mid 50s to near 60 over the W Piedmont from the low-mid 60s over
the far E Piedmont, Sandhills, and Coastal Plain. Observed mid level
trends noted on 00z UA analyses support model progs of building
ridging aloft over the Carolinas, including drying and sinking mid
levels in conjunction with decreasing PW over the area. With a dry
column and neutral to sinking air, clouds will be few and far
between today, limited to high-based flat convective clouds, mostly
scattered except more numerous near an expected inland-moving sea
breeze in the mid-late afternoon. This strong heating will allow
temps to reach well into the upper 80s to around 90, with low level
thicknesses nearly 25 m above normal. Expect generally clear skies
tonight, with only light fog expected in the far SE due to slightly
higher dewpoint depressions (due to slightly warmer temps) and a
slight stirring with a very light SE breeze overnight. Lows will be
just a bit higher than this morning, 60-65. -GIH

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 230 AM Thursday...

The mid level ridge axis stretching over the Carolinas today is
expected to shift ESE by early Fri, kicked to our E by the series of
weak mid level perturbations riding through the base of the mean
broad W CONUS trough and into the Mid South and western Carolinas.
Latest model runs agree on continued low PW over the area Fri with a
lack of both SBCAPE and forcing for ascent, although this starts to
change late in the day and into Fri night, as the low-PW air shifts
to E NC with increasing deep layer moisture spreading in from the
west, in conjunction with the arrival of the first mid level wave
(likely a dying MCV from today`s S Plains convection) into and over
the central and southern Appalachians late Fri into Fri night. This
wave will be further dampening as it arrives with poor mid level
flow and modest low level moisture flux, but with moisture amount
and depth increasing aloft and most long-range CAMs and larger scale
models showing scattered convection shifting into the NC Foothills
and eastward after 00z Sat, will bring in slight chance pops in the
Triad region in the evening, spreading further E with chance pops
over the W Piedmont overnight. Skies should still be fair for much
of the day with high clouds abundant but thin, and with thicknesses
still 25-30 m above normal, expect highs again in the upper 80s to
around 90. Lows in the low-mid 60s with increasing clouds. -GIH


&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 315 PM Wednesday...

Strong upper level ridge will move offshore early Saturday. A series
of shortwaves will move across the region early next week. At the
surface, high pressure will influence the Mid-Atlantic region. By
Saturday morning confidence in the forecast becomes better than it
has in the past few days. Latest data shows by Saturday morning
increased moisture values of 1.5+ ahead of a cold front moving
across the TN and OH valley. As the front moves into the region it
will bring isolated to scattered showers and storms to the area
Saturday and again Sunday. The cold front will move across the
region Sunday before stalling across the region on Monday. Less
coverage is expected on Monday but depending where the front stalls,
isolated to scattered showers and storms could be possible
especially in the afternoon with daytime heating. The stalled front
is expected to dissipate and most of Tuesday is expected to be dry,
but multiple long range models show another round of showers and
storms developing by late afternoon Tuesday ahead of another frontal
passage moving across the Southern Plains and Southeast.

Temperatures over the weekend will largely depend on timing and
coverage of the precipitation, but generally expect highs in the
upper 70s to low/mid 80s. Lows in the upper 50s and low 60s.
Temperatures are expected to increase through the week with highs 10
to 15 degrees above average by Wednesday. Most of the region will
see upper 80s to low 90s by Wednesday.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 1245 AM Thursday...

A period of MVFR to IFR vsbys in fog is expected at FAY/RWI early
this morning, mainly 07z-13z, given the combination of high RH, weak
winds, and clear skies. Fog is also possible near RDU during this
time window, but confidence is lower there, and it may manifest into
just shallow dense ground fog over bodies of water. INT/GSO should
remain fog-free this morning. Otherwise, VFR conditions are likely
areawide from mid morning through tonight, with weak high pressure
at the surface and stronger high pressure building in aloft, keeping
cloud cover minimal. Surface winds will stay light, under 10 kts.

Looking beyond 06z Fri, VFR conditions are likely to hold through
Fri, although mid/high clouds will gradually increase from the west
as the high pressure ridge aloft gets pushed to our east by incoming
upper level waves moving in from the W and SW. The chance for sub-
VFR conditions within scattered to numerous showers and storms will
increase starting Fri night, lasting through Mon, as a series of
disturbances passes over the region. Areas of early-morning fog are
also expected. -GIH

&&

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

&&

$$

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