-- Discussion containing changed information from previous version are highlighted. --
473
FXUS61 KAKQ 091806
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
206 PM 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 1000 AM EDT Thursday...

-Key Message:

-SPC has reduced the severe threat from slight (level 2 out of
 5) to marginal (level 1 out of 5) for this afternoon. The
 threat is particularly low across the far northeast.

Complex wx pattern expected today. Remnant debris clouds and
light rain showers are spreading across the FA late this
morning, in association with a remnant OH River Valley MCS from
last night. However, the coverage of rain is spotty at best.
Have lowered PoPs through this morning and early this aftn as
sfc- based instability is quite limited and CAMs show no
shower/storm development in this timeframe.

The focus for any strong to severe storms later this aftn and
evening will be along a sfc boundary draped roughly from the NW
Piedmont into the Northern Neck and Eastern Shore. Overall, the
threat is very conditional and contingent on airmass recovery in
the wake of the aforementioned cloud cover. The biggest change
to the fcst has been the reduction in the severe threat from SPC
from slight (2 out of 5) to marginal (1 out of 5). N of the
boundary, there will be virtually no sfc- based instability
(low- level winds will be easterly/onshore), with svr wx very
unlikely. Along and S of the boundary, instability may increase
to adequate levels (500-1000 J/kg of MLCAPE). Given ~30 kt of
bulk shear over the area, the parameter space could support some
strong to severe storms. The sfc boundary may provide some
localized enhanced directional shear for an isolated spin- up
tornado. The latest HRRR runs continue to shower elevated 0-1
and 0-3km SRH (~200 m2/s2) by from about 20Z-00Z across the I-64
corridor (give or take ~30 miles). Otherwise, main threat would
be damaging winds and perhaps some isolated larger hail if any
supercells develop. 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 have been lowered significantly for most of today. PoPs
ramp up in close alignment with the latest hi-res model runs
favoring the highest coverage of storms (just rain N of the
boundary) roughly along and just NE of the I-64 corridor. PoPs
shift off the NE overnight and diminish (except across the far
NE) after 06z. Lows mid/upper 50s N to mid 60s S.

&&

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

-Key Message:

- Another round of showers/storms Fri aftn/evening. Widespread
  severe is not expected, but gusty winds and hail will be
  possible.

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.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As of 400 AM EDT Thursday...

-Key Message:

-Remaining unsettled (especially north) late Sat through Sunday,
 dry Mon, with rain chances returning Tue-Wed.

The weekend continues to look a bit unsettled, especially across
the N/NE portion of the CWA as yet another shortwave drops SE
from the wrn Great Lakes, and pushes 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.
Cool Sat with highs in the low-mid 60s NE to around 70F over the
SW. The airmass will be fairly dry so not expecting much QPF
with this system (generally 0.10" or less with a little more
possible across the NE). Will have PoPs to ~40% over the N late
Sat/Sat night into early Sunday, with PoPs only ~15-20% in NC.
The models still differ with respect to the strength of the
upper trough on Sunday, so will maintain PoPs up to 25-30%
across the NE, while southern VA and NE NC should be dry.
Remaining cool with highs in the 60s NE to the low-mid 70s SW. It
looks dry from Sunday night through Monday with lows in the 40s
inland to the 50s near the coast, followed by highs Mon in the
mid-upper 70s. Unsettled conditions return Tue as a southern
stream system moves ENE twd the mid Atlantic, and across the
area Wed. High chc PoPs for now.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
As of 205 PM EDT Thursday...

VFR at all terminals this afternoon w/ a developing CU field
across mainland VA and NC. Skies are mainly clear on the ern
shore (SBY). Also noting some higher clouds sliding through. A
frontal boundary is situated across central VA and winds are
light and variable near the front. To the S of the boundary,
winds are southerly. To the N of the boundary, winds are E/NE.
This boundary could serve to focus storm development later this
aftn and evening, especially near RIC. Elsewhere (ORF/PHF/ECG),
the shower/storm chc continues to trend lower. Any storm could
produce heavy rain, gusty winds, and small hail. SBY is also likely
to see rain showers this evening/tonight, but not expecting
thunder due to easterly onshore flow. IFR CIGs (and potentially
VSBY) are forecast at SBY late tonight in BR/FG. The front drops
further S early Fri morning, potentially serving to focus
additional showers/storms for Fri.

Outlook: Expect to see redeveloping showers/tstms later Friday
afternoon and evening (with flight restrictions expected).
Mainly dry most of Saturday, but another chance for showers
Saturday night into Sunday. Dry Mon.
-- End Changed Discussion --

&&

.MARINE...
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.

&&

.TIDES/COASTAL FLOODING...
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.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.

&&

$$

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