089
FXUS61 KAKQ 091932
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
332 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 /UNTIL 6 AM FRIDAY MORNING/...
As of 330 PM EDT Thursday...

Key Message:

- Conditional severe weather threat this evening with damaging winds
the primary threat.

Quiet wx locally this aftn as we await potential storms later this
evening. There remains a good deal of uncertainty surrounding the
storm potential, in particular whether sufficient destabilization
will be realized to fuel organized convection. However, compared to
the previous few days, a frontal boundary draped from NW to SE
across the local area (along w/ a weak shortwave aloft) will provide
an adequate source of lift and focus for convection. Based on the
latest CAMs (HRRR/3km NAM/NSSL-WRF), the highest chance for storms
will be focused along a line extending from LKU to RIC to FYJ. This
tends to agree well w/ current sfc obs showing an agitated CU field
in this same general vicinity. Continue to focus the highest PoPS
(50-60%) in this area, with lower PoPs (30%) further E/SE where
additional pop-up convection may develop, mainly near land/water
interfaces and any established sea breezes. Based on the latest
model data, our far SW counties are likely to stay dry through
tonight. N and NE of the boundary on the Northern Neck and Eastern
Shore, easterly onshore flow will keep these areas stable with
little to no risk of thunder. Regarding the severe potential, SPC
continues a marginal risk for the entire area; however, this is
likely overdone in the aforementioned areas N of the front. S of the
boundary, adequate instability (MLCAPE 500-1000 J/kg) and around 30
kt of effective shear would argue for at least some potential for
stronger storms this evening. In fact, several CAMs show a few
updraft helicity tracks across central VA this evening w/ transient
supercell features. Still, the overall extent of the svr threat is
much lower than originally thought yesterday and Tuesday due to last
night`s MCS activity moving to our S, preventing sufficient airmass
recovery in today`s warm sector. So...mainly expecting sub-severe
storms w/ an isolated storm or two capable of producing damaging
winds and perhaps some larger hail. There is very low chance of a
brief tornado near the front where low-level directional shear will
be maximized. Highest PoPs shift E tonight, tapering off after 6-
9z/2-5 AM. Fog may also move inland off the ocean onto the eastern
shore after ~midnight.

Temps this aftn are generally in the upper 70s and low 80s. With
scattered or broken cloud cover for most of the area, not expecting
temps to warm much more. Overnight lows range from the mid 50s N to
mid 60s S.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
As of 330 PM EDT Thursday...

Key Messages:

- Another round of showers/storms likely Friday afternoon and
evening. While widespread severe is not expected, a few stronger
storms are possible.

- Scattered showers possible Saturday with an upper-level
disturbance.

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 sfc front will also push S through the day. The potent
nature of the shortwave argues for continuing to trend PoPs up, with
60-70% in the forecast for most of the area now. Forecast soundings
show decently steep mid-level lapse rates w/ the cold pool aloft,
along with strong deep-layer shear (50-60 kt). The one caveat (and
likely limiting factor) will be the availability of any sfc
instability. At this time, the highest CAPE is currently forecast to
our S, though ~1000 J/kg of sfc-based CAPE may develop with some
higher dew points pooling along the sfc front. CAMs actually show
quite widespread convection, with several of the experimental MPAS
CAMs being quite aggressive w/ convective coverage. Additionally,
they show a predominantly cellular storm mode, arguing for the
potential for hail. The wind threat would be highest across the S
where the low-level lapse rates are steeper. Strong low-level shear
would also suggest a conditional tornado threat, given a favorable
storm mode and low-level thermodynamics. Highs on Fri will show a
large range, only in the upper 50s to lower 60s MD ern shore to the
low 80s interior NE NC. Temps gradually fall in the late aftn behind
the front. Drying out later Fri night and cooler with lows mid/upper
40s W to the lower 50s E.

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. Steep lapse rates again
suggest a few tstms are possible, though this environment will be
much cooler than the past few days. Cannot rule out some small hail
in the strongest cores (especially NW). 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
~50% over the N late Sat/Sat night into early Sunday, with PoPs only
~15-20% in NC. Chilly Sat night w/ upper 40s NW to low 50s SE. A
similar story is expected Sunday as the core of the upper low sits
just N of the area. This will focus additional showers across the MD
Eastern Shore, with lower chances extending SW into the Northern
Neck and Piedmont. Highs Sun a little warmer and in the mid 60s ern
shore to low-mid 70s elsewhere.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 330 PM EDT Thursday...

High pressure situates over the Mid-Atlantic Sunday night through
Monday night, favoring dry weather. Highs Monday warm back in the
upper 70s with overnight lows in the upper 50s-low 60s. The high
moves offshore Tuesday, with southerly flow funneling moist air
towards the region. Unsettled conditions and above average rainfall
are therefore expected later Tuesday through most of next week as
multiple southern stream systems move ENE towards the mid-Atlantic.
Thunderstorms are also possible mid to late week. Highs Tue warmest
across the E (where precip holds off longest) and in the upper 70s,
with lower 70s W. Temps next Wed and Thu hover a few degrees
above/below 80F w/ overnight lows around 60F.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
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.

&&

.MARINE...
As of 330 PM EDT Thursday...

-Key Messages:

-Small Craft Advisories have been issued north of Parramore Is.
from late Friday morning through Friday night.

-Additional Small Craft Advisories may be necessary Friday night
into early Saturday.

A stationary front lingers over the Mid-Atlantic coast this aftn,
with the wind ENE 10-15kt N of the boundary, and SW 5-10kt S of the
front. Seas are primarily 2-3ft. This boundary will linger over the
area tonight through Friday, before dropping S Friday night as low
pressure develops and tracks NE off the NC Outer Banks. A NE wind is
expected to increase to 15-20kt N of Chincoteague Friday with seas
building to 5-6ft. Therefore, SCAs have been issued N of Parramore
Is. beginning 10 AM Friday and continuing through 6 AM Saturday at
this time, but this will likely need to be extended. Otherwise, the
wind is expected to become N and increase to 15-20kt Friday night
into early Saturday, with seas building to 4-6ft and 2-3ft waves in
the Ches. Bay. Additional SCAs are likely Friday night into early
Saturday.

A secondary front tracks across the coast later Saturday
aftn/evening. The wind becomes SE 10-15kt ahead of the front and
then shifts to NW late Saturday night/early Sunday. The current
forecast is sub-SCA, although some guidance suggests low-end SCA
conditions are possible over the Ches. Bay. High pressure builds
over the coast later Sunday into Monday. Another low pressure system
and cold front impact the Mid-Atlantic coast in the Tuesday-
Wednesday timeframe.

&&

.TIDES/COASTAL FLOODING...
As of 330 PM EDT Thursday...

-Key Message:

-Minor tidal flooding is possible during high tide Friday night into
early Saturday.

Another elevated astronomical high tide is forecast for tonight
into early Saturday. At this time, tidal anomalies have been steady
and the past flood tide was relatively weak. Therefore, water levels
are largely expected to remain below minor flood thresholds for
tonight/early Saturday, with the exception of some the more
sensitive locations. An increasing NE then N wind Friday night into
early Saturday will bring the potential for minor tidal flooding
with yet another elevated astronomical high tide.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 10 AM Friday to 6 AM EDT Saturday
     for ANZ650-652.

&&

$$

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