111
FXUS61 KAKQ 081117
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
717 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 towards
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/...
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.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 415 AM EDT Wednesday...

There remains some uncertainty for the weekend, but overall the
model agreement is improved compared to yesterday`s 12Z runs.
The main WX maker will be yet another shortwave dropping SE and
pushing across the mid Atlantic late Sat through Sunday. This
pattern favors increasing clouds Sat aftn, with low chc PoPs
pushing into the NW by late aftn, 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. Temperatures 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 /11Z WEDNESDAY THROUGH SUNDAY/...
As of 200 AM EDT Wednesday...

Earlier IFR/LIFR on the eastern shore has moved off the coast so
all terminals are now VFR. Winds are mostly light SW, and will
become WSW at ~10 kt later this morning/aftn. A brief morning
shower could affect SBY, but for the most part expect partly
sunny and mainly dry conditions through 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 04Z/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. Mainly VFR overnight, but
showers/tstms potentially ramp back up in coverage prior to
12Z/Thu.

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 530 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 show improving
visibility across the northern coastal waters and the Marine
Dense Fog Advisory has been cancelled. Visibility may still fall
to 1 to 3 SM at times in patchy fog early this morning. 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...
As of 530 AM EDT Wednesday...

A combination of high astronomical and flood tides at the mouth
of the bay will lead to areas of nuisance to minor coastal
flooding on tonight`s high tide cycle. Tidal anomalies remain
around 1 foot early this morning with light southerly flow.
Water levels along bay-facing portions of the MD Eastern Shore
will approach or exceed minor flood thresholds tonight and a
Coastal Flood Advisory has been issued for these areas.
Locations along and adjacent to the tidal Potomac
(Lewisetta/Windmill Pt) will approach but fall short of minor
flood thresholds. Therefore, a Coastal Flood Statement has been
issued for these areas late tonight. Elsewhere, nuisance tidal
flooding is possible but not expected to be impactful enough for
additional statements.

&&

.CLIMATE...
Record highs for today May 8th:

* RIC: 92 (1936)
* ORF: 95 (1880)
* SBY: 93 (1936)
* ECG: 91 (2010)

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Coastal Flood Advisory from 10 PM this evening to 7 AM EDT
     Thursday for MDZ021>023.
NC...None.
VA...None.
MARINE...None.

&&

$$

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