-- Discussion containing changed information from previous version are highlighted. --
619
FXUS62 KRAH 231808
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
206 PM EDT Thu May 23 2024

.SYNOPSIS...
A warm and humid air mass over our region, combined with the passage
of a series of upper level disturbances over the area, will produce
unsettled weather through Monday, with daily chances of showers and
storms. A drier air mass will arrive by the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 920 AM Thursday...

Marginal Risk of severe thunderstorms this afternoon and evening.

Satellite and radar data indicate several MCV`s that may affect
portions of the region this afternoon and tonight. An initial MCV
was producing thunderstorms over portions of NE Tennessee. Another
was located in AL/GA and still another approaching the Tennessee
Valley region. The CAMS have backed off a bit on convection in
central NC this afternoon, holding off until late day and tonight.
We are not totally biting off on this scenario due to the forecast
CAPE values of 1500 to 2000 j/kg, but we will delay timing slightly
and lower initial POP. It appears the best chance of thunderstorms
will be in the NW associated with the initial wave in the afternoon.
This will be followed by the additions waves and potential
convection later in the and tonight. Highs in the mid to upper 80s
NW and upper 80s to lower 90s elsewhere.

&&

.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
As of 200 PM Thursday...

Confidence for Friday continues to be low with inconsistency for
timing and coverage. An upper level shortwave is expected to move
across the region bringing plenty of moisture through out the
atmosphere with PW values around 1.60 inches, which is slightly
above the daily average. Marginal to moderate CAPE across much of
the region especially in the southern half of the CWA mixed with
temps in the mid/upper 80s and dew points in the upper 60s to low
70s could result in a few isolated to scattered storms developing
across the region in the afternoon and early evening. It is not
expected to be a complete wash out across the region but some storms
could become strong and slow moving. For now, keeping chance pops
this afternoon and continuing overnight for showers and isolated
storms, but again, confidence of this is low. Overall, some breaks
in the clouds during the first half of the day, increased cloud
coverage and chance of storms second half of the day and continuing
into overnight. High will range from mid 80s in the north to upper
80s in the south. Lows will generally be in the mid to upper 60s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 310 AM Thursday...

Daily chances for showers and storms are expected Sat through Mon,
with pops decreasing by Tue/Wed with a shift in the longwave
pattern.

The aforementioned Fri night shortwave trough is expected to be over
central or eastern VA/NC Sat morning. If this feature is a bit
slower, then the cooler mid levels and DVPA may prompt high coverage
of storms with heating across our east. If this wave is faster, then
that will bring rearward shortwave ridging into our area Sat,
reducing our pops. With our area firmly in warm/moist advection, PW
still above normal, and surface troughing still in place over the
area, will lean on the high side of climo pops, esp E, with 40% NW
ranging to 55-60% SE Sat. Expect a brief downturn in pops late Sat
night through much of Sun as the shortwave ridging passes overhead
coincident with a dip in PW, but with upstream convection in the
Plains and Miss Valley continuing to eject perturbations through the
Mid Atlantic region with no real pattern change for us at the
surface, we should see convection chances quickly return, and will
retain chance pops Sun afternoon and evening. We start to see signs
of a longwave pattern change starting Memorial Day, as a deep
northern stream low/trough moves into the Midwest/Great Lakes. This
will set up faster and more cyclonic mid level flow with steepening
mid level lapse rates, suggesting high pops, esp late in the day and
into Mon night. Will have good chance to likely pops, highest Mon
afternoon/evening. As longwave troughing sets up over E NOAM,
Tue/Wed should be fairly dry with below-climo chances for showers
and storms.

Thicknesses will hold above normal Sat, favoring highs in the 80s to
near 90, then highs will reach peaks of mid 80s to lower 90s Sun and
Mon, pushing heat indices well into the 90s all but the far N. By
Tue, as the upper trough axis and associated cold front move
through, temps should drop back close to normal. -GIH

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
As of 206 PM Thursday...

Generally VFR conditions are expected through tonight. There is
chance of a shower or thunderstorm that could produce brief MVFR to
IFR conditions, mainly this afternoon and evening. A brief shower can not
be ruled out overnight.

Late tonight, patchy fog and low stratus are possible near FAY tonight
into Fri morning, but given inconsistencies in prior convection
this threat also includes low predictability.

Looking ahead: Primarily diurnally driven showers/storms will be
possible at all terminals Fri through Mon, with the highest chances
on Saturday and Monday afternoon and evenings.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...Hartfield
NEAR TERM...Badgett
SHORT TERM...CA
LONG TERM...CA
AVIATION...Badgett/Swiggett