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398
FXUS61 KAKQ 080800
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
400 AM EDT Wed May 8 2024

.SYNOPSIS...
Summer-like conditions with daily showers and storms are
expected through Thursday, with a cold front expected to push
through the region late Thursday through Friday. An upper level
trough will keep a chance for showers late Saturday into Sunday,
with dry conditions expected Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 330 AM EDT Wednesday...

Key Messages:

-Marginal SVR risk today for most of the region (slight risk SW
 zones)

- Hot today with highs in the upper 80s/lower 90s

The latest WX analysis indicates sfc low pressure over the upper
peninsula of Michigan, with high pressure well off the SE coast,
and a lee trough over the local area. Aloft, there are two
separate areas of low pressure: one across the Dakotas/nrn
rockies, and another near the sfc low over northern Michigan.
There is a weak ridge aloft locally, but that will be
flattening out later today as the upper trough over Michigan
translates E to upstate NY and New England by this evening.

It remains mild and dry early this morning with temperatures
mostly in the 60s. Partly cloudy, except for the MD eastern
shore where some low clouds and fog remain in place through the
next few hrs. There is a large scale area of showers/tstms over
thr OH Valley that m,may spread a shower to the far twds
sunrise but for the most part this will only lead to some
additional high clouds. SPC has a Marginal risk for severe for
most of the CWA today, with a Slight across the SW zones (from
about Farmville to Bertie Co. NC). Shear will be increasing
today as the H5 gradient tightens in response to the trough
moving from MI to New England. The 0-6km shear this aftn/evening
will increase to ~40 kt, and ML CAPE will be 1000-2000 J/Kg
(highest over the south). As such, any storms that do develop
will have the potential to become severe w/ wind as the primary
threat (though mid level lapse rates are modestly steeper than
yesterday so some large hail will also be possible). Probably
the main reason that most of the CWA is only in a Marginal is
due to the lack of a trigger for convection other than a weak
lee trough. PoPs this aftn will mostly hold off until late
aftn/early evening and will be highest across the south
(30-40%), and lowest over the NE (~20%). It will be hot with
highs into the upper 80s to lower 90s. The bulk of guidance
suggests that the best chc for storms will actually be this
evening as a band of slightly steeper mid level lapse rates are
progged to push through. PoPs diminish for awhile late in the
evening/early thu morning, but then most of the CAMs depict an
MCS potentially moving in from the W between 06-12Z Thu
morning. Will show PoPs ramping up to 40-50% late. Warm with
lows in the mid to upper 60s.


 &&

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

While somewhat uncertain given the potential MCS (or remnants)
passing through the region Thursday morning, SPC maintains a
SLight Risk for Severe across the entire FA. This as the mid
level wind field increase further (H5-H7 flow to >50kt), along
with the approaching upper trough leading to height falls and
provide more widespread forcing for ascent. The timing will be
tricky and have enough support for high chc to low-end likely
PoPs Thursday morning (this could be one of the relatively rare
cases where we see decent tstm activity during the morning hrs).
The degree to which this AM shower/storm activity lingers into
the late morning/midday hrs Thursday could have impacts on the
aftn instability to some extent. However, it is notoriously
difficult to time these features (even in the <24 hr timeframe)
and the models tend to perform poorly in their development and
evolution. Damaging winds and large hail continue to look like
the most likely threats from any storm. Given the frontal
forcing, it seems probable that storms would eventually grow
upscale in a linear or broken line feature, with widespread
damaging winds becoming increasingly favored. Low- level
hodograph curvature is also somewhat enhanced near the front,
though high LCLs would argue against a robust tornado threat.
With more clouds around, high temps will be cooler and generally
in the upper 70s/lower 80s N to the mid/upper 80s SE. PoPs
diminish from W to E Thursday evening, then dry overnight.
Turning cooler Thu night with lows in the upper 50s-low 60s.

Friday starts off mainly dry, but scattered showers are
expected to redevelop as the upper trough swings through and the
associated shortwave moves across VA and the Carolinas. There
will be limited sfc-based instability but the cold pool aloft
could set off some tstms, mainly across the southern 1/2 of the
CWA. At this time, severe wx is not expected. Highs on Fri will
be cooler, mainly in the lower to mid 70s (upper 70s possible
far S). PoPs are highest over the SE (~50%) and lowest over the
far W. Drying out Fri night and cooler with lows mid/upper 40s W
to the lower 50s E.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
As of 300 PM EDT Tuesday...

There remains some uncertainty for the weekend. The 12z
deterministic GFS continues to phase the upper trough with srn
stream energy Fri night (this is because it is slower and more
amplified with the trough). This leads to sfc low pressure
formation along the baroclinic zone just offshore of the
Carolinas. Such a scenario would push widespread stratiform
rainfall N towards the FA Fri evening and overnight. The 12z
ECMWF suppresses this feature further S as it is depicts a more
neutral trough tilt. At this time, will keep the highest PoPs
across the SE assuming the sfc low passes well to our S. Beyond
this, the weekend weather pattern will feature yet another upper
trough diving SE from the Great Lakes and passing off the mid-
Atlantic coast Sat night through Sunday. The airmass will be
cooler and fairly dry but will continue w/ 20-30% PoPs (highest
N) for Sat night through early Sun aftn. It looks mainly dry
from late Sunday through Tuesday with seasonable temperatures
(highs in the 70s with lows in the upper 40s to mid 50s),
potentially warming further into the middle of next week.
-- End Changed Discussion --

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
As of 200 AM EDT Wednesday...

IFR/LIFR on the eastern shore as an area of marine fog and low
stratus has spread inland, with VFR conditions elsewhere under
BKN mid/high clouds. Winds are mostly light/variable. Flight
restrictions across the eastern shore should improve through 12Z
(lingering the longest at the Atlantic coast), otherwise partly
sunny and mainly dry with WSW winds through the rest of the
morning into the mid/late aftn period. Widely scattered mainly
late afternoon and evening showers and thunderstorms develop,
with enough of a chc between ~21Z today and 03Z/Thu to include
VCTS(lower chance at SBY so did not include it there). IFR VSBYs
will be possible in any tstms, along with strong gusty winds.

Outlook...Active pattern on Thu with at least a chc for
showers/storm all day (even in the morning). Some strong storms
will be possible. Drying out from W to E Thu evening, then VFR
Fri, but there will be a chc for showers/isolated tstms
redeveloping Fri aftn into Fri evening. Mainly dry Sat, but
another chc for showers Sat night into Sunday.

&&

.MARINE...
As of 330 AM EDT Wednesday...

Surface high pressure remains off the Southeast coast with multiple
areas of low pressure over the Plains and another low centered near
Michigan. Flow aloft is largely from the SW between a closed low
over the northern Plains and ridging over the Gulf of Mexico. Winds
are S at 5-10 kt early this morning with waves around 1 foot and
seas 2-3 ft.

Satellite and surface/buoy observations continue to show areas of
fog over the northern coastal waters where a Marine Dense Fog
Advisory continues until 7am. SW winds will generally stay in the 5-
10 kt range today ahead of weak lee troughing over inland areas.
Guidance is mixed with respect to the potential and coverage of
showers and thunderstorms across the waters this afternoon/evening.
However, the environment will support strong storms if they are able
to form and locally enhanced winds/waves/seas are likely in and near
any convection that is able to materialize. Sub-SCA flow continues
Thursday and with somewhat greater potential for strong storms
(highly dependent on how convection evolves upstream). Flow becomes
westerly on Friday as the surface front crosses the region. 00z
guidance has come into better agreement showing a period of cold
advection/stronger NW winds Friday night into early Saturday. This
period may require SCA headlines in subsequent forecasts. The NNW
surge looks to be short-lived with SE flow reestablishing for the
second half of Saturday. Another front potentially moves through the
region on Sunday with winds becoming NW behind the boundary, though
currently forecast to stay below SCA thresholds. Waves will
generally maintain 1-2 ft through the period but could increase to 2-
3 ft Friday night/early Saturday. Near-shore seas will average 2-3
ft with 3-4 ft more prevalent out near 20 NM.

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
As of 330 AM EDT Wednesday...

All coastal flood advisories have been cancelled. Additional
nuisance to minor coastal flooding is possible with the high tide
cycle late tonight and further headlines will be issued later this
morning.
-- End Changed Discussion --

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...None.
NC...None.
VA...None.
MARINE...Dense Fog Advisory until 7 AM EDT this morning for ANZ650-652.
-- End Changed Discussion --

&&

$$

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