953
FXUS62 KRAH 021822
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
220 PM 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 933 AM Thursday...

The Dense Fog Advisory has expired as of 9 AM as visibility has
rapidly improved this morning. Today will likely rival the warmest
day of 2024 so far this year. Low-level thicknesses this morning
from region RAOBs are 10-20m greater than 24 hours ago and 850mb
temperatures at GSO are equal to the moving 90th percentile for
early May. The steep early morning surface inversion is rapidly
eroding and has resulted in air temperatures rising 5-10 degrees
from 12 to 13z. A steady climb is expected through the afternoon
hours with highs reaching to upper 80s in most locations with some
locations able to reach 90 degrees for the first time this year. The
previous forecast remains on track with only minor tweaks made to
the sky and hourly temperatures for the mid-morning update.

Previous discussion 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 THURSDAY/...
As of 220 PM Thursday...

The first half of the extended forecast will feature an unsettled
pattern. A weak surface low will be over the Ohio River Valley
Saturday morning, slowly move to the east over Virginia by Sunday
morning, then dissipate. A cold front will extend to the south from
the low, and the front will be the primary rain-maker over the
weekend. Extended likely pops a bit farther to the east both
Saturday and Sunday. Rainfall amounts will range from a quarter inch
in the southeast to nearly an inch in the northwest - needed
rainfall, but not enough to change the drought status (almost all of
which is D0 - abnormally dry - in our area). All locations will have
at least a slight chance of thunderstorms, although instability
values will be a little higher in the west. After the upper 80s and
lower 90s of today and tomorrow, highs will be more seasonable for
the weekend, ranging from the upper 70s the mid 80s.

An upper level trough will approach the area Monday and move
overhead Tuesday, bringing a chance of showers and thunderstorms to
all locations. The forecast should then generally dry out for the
middle of the week. However, an upper ridge will build across the
Carolinas, and with southwesterly surface flow, temperatures will
rise above normal again. By Wednesday and Thursday, highs should be
in the lower 90s with lows around 70, values more typical of July
and August than early May.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
As of 125 PM Thursday...

VFR fair weather cumulus has developed mainly across the Sandhills
and southern Coastal Plain, affecting FAY, will quickly disperse
shortly after sunset. Light winds out of the southeast will slowly
veer around to southwesterly by Sat afternoon. Crossover
temperatures will be more difficult to achieve tonight compared to
this morning and result in less favorable fog potential. Shallow
moisture advection off the Atlantic and pockets of radiational
cooling may develop another round of fog, potentially dense in
spots, but probabilities are more favorable south of FAY.

Looking beyond 18z Fri, VFR conditions are likely to hold through
Fri, although mid/high clouds will gradually increase from the west.
The chance for sub-VFR conditions within scattered to numerous
showers and storms will increase starting late 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...Swiggett/Hartfield
SHORT TERM...Hartfield
LONG TERM...Green
AVIATION...Swiggett/Hartfield