-- Discussion containing changed information from previous version are highlighted. --
829
FXUS61 KAKQ 090800
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
400 AM EDT Thu May 9 2024

.SYNOPSIS...
A cold front will slowly push through the region later today
through tonight, bringing showers and thunderstorms to the
region. An upper level trough will bring another round of
showers and storms later Friday into Friday night. A chance for
showers continues across mainly northern areas over the weekend.
Dry and warmer weather to start next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 340 AM EDT Thursday...

A complex WX pattern in place for today, with the weakening
remnant of earlier convection over the Tn Valley now pushing
through central NC and over south central VA. Still dry across
the FA, but expect a few showers to move into the southern zones
over the next few hrs. There is no sfc-based CAPE over the local
area (an just very limited ML CAPE to ~250 J/Kg over the far
southern areas) so these will just be showers with embedded
tstms. Some gusty winds to ~40 mph will be possible over the
south this morning, but severe WX is not expected this morning.
Expect a few hrs w/ little to no precip late morning/early-mid
aftn, followed by PoPs ramping back up by later aftn.

While SPC has a Slight Risk for the entire CWA today, a
more southerly position of a developing sfc low/boundary this
aftn (in the vicinity of the I-64 corridor), lends to a lower
risk for SVR later today to the NE (especially the eastern shore
where aftn temps will barely be in the 70s (or cooler) with
little to no ML CAPE and no sfc- based instability. This sfc
boundary later today will likely act as a focus for re-
developing storm activity later this aftn into early this
evening, and may provide some localized enhanced directional
shear for an isolated spin-up tornado. The last few HRRR runs
show 0-3KM SRH values to ~300 m2/s2 by from about 20Z-00Z
across the I-64 corridor (give or take ~30 miles). The overall
instability appears to be less than what was expected yesterday,
but still should approach ML CAPE ~1000 J/Kg to the S of the
boundary, along with deep layer shear of 40-50kt so localized
damaging winds will be possible. High today will be in the
mid/upper 80s in NE NC, but only in the 70s over the N (with
readings falling into the 60s near the Atlantic coast of the ern
shore).

PoPs remain high chc to likely in the early evening, shifting
off to the NE overnight, and diminishing except across the far
NE after 06Z. Lows mid/upper 50s N to mid 60s S.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
As of 350 AM EDT Thursday...

Friday starts off mainly dry (with some lingering low clouds and
light rain possible over the MD eastern shore). Scattered
showers are expected to redevelop as the upper trough dives SE
and swings through. The associated shortwave moves across VA
and the Carolinas and has trended stronger so have raised PoPs
by late aftn/evening to likely for most areas. With steep mid
level lapse rates expected w/ the cold pool aloft, at least
scattered tstms are expected for most of the area. SPC does not
have the area outlooked for any SVR, but would not be surprised
to see some hail and gusty winds given the steep mid level lapse
rates Fri evening. Highs on Fri will show a large range, only in
the upper 50s to lower 60s MD ern shore to near 80F interior NE
NC. Drying out later Fri night and cooler with lows mid/upper
40s W to the lower 50s E.
-- End Changed Discussion --

&&

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

There remains some uncertainty for the weekend, but overall the
model agreement is improved compared to yesterday`s 12Z runs.
The main weather maker will be yet another shortwave dropping
SE and pushing across the mid Atlantic late Sat through Sunday.
This pattern favors increasing clouds Sat afternoon, with low
chance PoPs pushing into the NW by late afternoon, spreading
through the region Sat night/early Sunday. The airmass will be
cooler and fairly dry so not expecting much QPF with this system
(unless the trough and shortwave were to push farther S than
any of the guidance currently shows). Will keep ~30% PoPs over
the N Sat night into early Sunday, with PoPs only ~10% in NC.
The models start to differ more on Sunday, with the
deterministic ECMWF the southern outlier regarding the track of
the upper trough. The NBM as well as the GFS and Canadian are
drier so will only keep PoPs around 20% through Sun aftn over
the north. It looks dry from late Sunday through midday Tuesday
with some low chc PoPs possible by later Tuesday as the next
upper trough approaches from the lower MS/TN Valley. Temps will
be near to slightly below normal Sat-Sun (highs upper 60s to
mid 70s), warming a bit by Mon-Tue (highs mid/upper 70s).

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
As of 200 AM EDT Thursday...

Mainly VFR this morning w/ brief MVFR/IFR restrictions in
morning showers (most thunder stays S of the main terminals
other than ECG). Shower and thunderstorm chances increase
later this aftn into this evening. Any showers/storms may
produce brief periods of reduced VSBYs and CIGs. Storms into
this evening could be on the stronger side and produce gusty
winds (except over SBY where they will mainly just be showers).


Outlook: Drying out from W to E overnight, then VFR Friday, but
there will be a chance for showers/isolated tstms redeveloping
later Friday afternoon and evening (with flight restrictions
expected). Mainly dry Saturday, but another chance for showers
Saturday night into Sunday. Dry Mon.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
As of 345 AM EDT Thursday...

Primary area of low pressure is centered near St. Louis early this
morning with a cold front extending down to the S and SW into NE TX.
A stationary front remains draped across the Midwest and eastward
along the Mason Dixon line and further NE into another area of low
pressure over New England. Winds aloft are largely W-SW with several
perturbations/kinks noted in the flow. Winds locally are from the W
or SW 5-10 kt with gust to 15 kt. Waves in the bay are 1-2 ft with
seas 2-3 ft.

Complex scenario is expected to unfold today with most guidance now
showing the stationary front making south and southwestward progress
in a backdoor fashion this morning. Winds behind the boundary will
generally be easterly 10-15 kt while areas to the south of the front
will see continued S or SW flow around 10 kt. One of the
aforementioned shortwaves aloft will result in weak surface
cyclogenesis inland this afternoon which should cause the boundary
to stall across the local waters later this afternoon into the
evening hours. Guidance is quite variable regarding the potential
for and coverage of showers and thunderstorms this afternoon with
substantial convection upstream lending uncertainty regarding the
degree of local destabilization this afternoon. Any storms that are
able to form will pose a threat for strong winds this afternoon and
evening. There is even a chance for tornadoes/waterspouts if a storm
is able to ride along the frontal boundary. The front will linger
across the area tonight with widely varying wind directions on
either side of the boundary. Low pressure develops along the front
Friday evening which will steepen the pressure gradient with NE
winds increasing to 15-20 kt in the Ches Bay, lower James River, and
Currituck Sound while offshore zones see closer to 20-25 kt. SCA
headlines are likely Friday night into Saturday before deepening low
pressure pulls away from the region. 1-2 ft waves in the bay will
persist through most of Friday before increasing to 2-3 ft late
Friday into Saturday. Seas generally maintain 3-4 ft through Friday
afternoon but increase to 4-6 ft by early Saturday morning.
Improving marine conditions are expected later on Saturday with seas
likely falling below SCA thresholds Saturday evening.
-- End Changed Discussion --


&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
As of 345 AM EDT Thursday...

Coastal Flood Advisories continue for bayside portions of the MD
Eastern Shore through 7 am. The subsequent high tide this
afternoon is not expected to cause any coastal flooding but the
next high tide could see another round of nuisance to minor
flooding in these same areas late tonight.
-- End Changed Discussion --

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Coastal Flood Advisory until 7 AM EDT this morning for
     MDZ021>023.
NC...None.
VA...None.
MARINE...None.

&&

$$

SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...LKB/SW
AVIATION...AJB
MARINE...RHR
TIDES/COASTAL FLOODING...AKQ