924
FXUS62 KRAH 181032
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
633 AM EDT Sun Aug 18 2024

.SYNOPSIS...
A cold front approaching from the northwest will move gradually
eastward through the region today through Monday. A cooler and less
humid air mass will settle into the area from Monday night through
Friday.

&&

.NEAR TERM /TODAY AND TONIGHT/...
As of 235 AM Sunday...

...There is a slight risk (level 2 of 5) for severe storms from
Raleigh south and east Sunday afternoon and evening...

...There is also a marginal risk for excessive rainfall over
portions of eastern NC...

All the earlier convection has died off leaving only some mid and
high level cloudiness. It continued very warm and humid. We will
start the day with some low stratus, but that will burn off fairly
quickly by mid-morning.

The approaching trough is rather anomalous for August over the Ohio
Valley and Great Lakes. The trough will gradually move east today
and will be approaching the region during the late afternoon and
evening. While the best mid level flow will be just north of our
region, the flow will be strong enough for aiding thunderstorm
organization along the pre-frontal trough and the actual cold front.
CAMS suggest a couple of rounds of convection will be possible this
afternoon and then with the actual front this evening. MLCapes
should reach the 2000-2500 J/kg with plenty of heating. There is a
marginal to slight risk of a few severe thunderstorms this afternoon
and evening, with the higher risk in the eastern Piedmont east to
the coast. The main threat will be damaging wind gusts. PW`s up to 2
inches in the Coastal Plain and 1.8 over the Triangle may aid in the
heavy rain potential. However, most areas have had a week to begin
to dry a bit after Debby. Therefore, the FFG values have come down
to more reasonable values. Highs today generally 85-90 expected.
Convection will end later this evening and early in the overnight.
Otherwise, low stratus will be possible late tonight. Lows in the
mid 60s N to lower 70s SE.

&&

.SHORT TERM /MONDAY AND MONDAY NIGHT/...
As of 303 AM Sunday...

There is a marginal risk of severe storms in eastern NC on Monday
afternoon and early evening.

The main cold front will be moving through the eastern Piedmont to
the Coast during the day. However, the best heating and instability
is expected in the Coastal Plain into the Coastal Area where the
front will be moving through during peak heating. This region will
likely have the best chance of organized thunderstorms with some
local damaging wind gusts possible. Back over the Piedmont, the base
of the upper trough will swing through, but instability and surface
convergence will be lower than those that will exist down east. CAMS
suggest that there will be scattered thunderstorms with this
feature; however, these storms should be less robust. Highs will be
cooler and should range in the lower to mid 80s west and north, and
upper 80s SE.

Cooler and less humid air (a real break from typical August heat)
will arrive Monday night. Lows will dip into the upper 50s to lower
60s north and mid to upper 60s SE.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
As of 320 AM Sunday...

An unseasonably deep upper level trough will encompass most of the
eastern US Tuesday between strong ridges over the northern Atlantic
and southwestern US.  The strong shortwave digging through the
trough today and tomorrow will move east of NC by Tuesday, but it
appears there will be additional pieces of energy diving into the
back side of the trough to maintain the mean trough axis trough the
region through midweek.  However, with a 1024mb high shifting across
the Midwest and a notable airmass change Monday that results in
dewpoints falling into the 50s by Wed/Thu, the forecast is dry
through the end of the week.  Under the trough, 1000-850mb
thicknesses are forecast to drop into the 1370s and 1380s, 30m or so
below normal, resulting in highs as much as 5-10 degrees below
normal in the upper 70s to lower 80s by Thursday.  The lower
dewpoints will also support overnight lows in the mid and upper 50s
in many locales.  The cool down will be relatively short lived
however, as the upper ridge over the SW US is forecast to build east
across the Deep South by next weekend and highs will trend back
toward normal.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
As of 633 AM Sunday...

Generally VFR conditions with some higher cloudiness can be expected
through 18z today. The exception will be between 09z and 13z in
which some stratus (IFR) is expected. Scattered thunderstorms are
expected this afternoon and evening, with brief IFR conditions
possible.

Looking beyond 00z Mon, Some lingering storms are expected through
04z/Monday. Otherwise, stratus is possible again around daybreak
Monday. Another round of scattered storms is possible at all sites,
but mainly RWI/FAY, Monday afternoon. VFR conditions should return
Mon night and prevail, with high confidence, through Thu.

&&

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

&&

$$
SYNOPSIS...Badgett
NEAR TERM...Badgett
SHORT TERM...CBL
LONG TERM...BLS
AVIATION...Badgett