393
FXUS61 KAKQ 030741
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
341 AM EDT Fri May 3 2024

.SYNOPSIS...
A backdoor cold front pushes into the Maryland eastern shore
late tonight, then inland across the remainder of the area on
Friday, leading to much cooler conditions at the coast. Rain
chances return Friday evening through Sunday as a series of
disturbances impact the region. Summerlike conditions return
to the area by the middle of next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 335 AM EDT Friday...

Early morning sfc analysis shows high pressure still anchored over
the Atlantic off the coast of the SE CONUS. Meanwhile, a backdoor
cold front is located just to the north of the local area. Aloft, an
amplified ridge extends into Canada with its axis just to the west
of the FA. Temps this morning will be fairly mild with temps
remaining in the 60s for most places (upper 50s in the NW). The
backdoor front will sag south today, creating non-diurnal temps that
will have a sharp gradient from NE to SW. For most locations W of
the bay, expect temps to quickly warm into the low 80s by mid-
morning, while the Northern Neck and the Eastern Shore remain cool
in the upper 50s-low 60s. Through the afternoon, cooler temps will
spread inland. Mid-afternoon temps will be in the 50s on the
Eastern Shore, 60s across the peninsulas and the SE coast,
while the central and southern piedmont will be in the mid-upper
80s. Clouds will increase through the day, becoming broken to
overcast by the afternoon. Winds turn to the NE behind the front
and become breezy, gusting to 20-25mph. There is a slight
chance for showers/thunderstorms in the piedmont this afternoon,
but CAMs indicate isolated coverage. Showers likely increase in
coverage late in the evening and overnight, but still look
limited to the piedmont and still scattered (40-50% PoPs). Lows
tonight/tomorrow morning will be a bit cooler than this
morning, dropping into the 50s.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
As of 905 PM EDT Thursday...

Key Messages:

- Increasing clouds from NE to SW Friday into Friday night as a
  cold front drops across the region.

- Rain chances increase mainly west of the bay tomorrow
  afternoon into tomorrow evening. Lighter, intermittent
  rainfall possible along the coast tomorrow night and into
  Saturday.

The backdoor front will continue to move SW across the region on
Friday. Models have good timing on the front, reaching the VA
eastern shore and SE VA Friday morning, the RIC metro around lunch
time, then to the southern Piedmont of VA by late afternoon.
Latest CAMs show some pop up showers for areas mainly west of
I-95 as the front moves SW. Have therefore included slight
chance PoPs for the afternoon in that same general region. Could
not completely rule out thunder as the HREF mean SBCAPE shows
500-1000 J/KG. There will be quite a gradient of temperatures
across the area, with Ocean City likely staying in the 50s
through the day, while areas in the southern Virginia Piedmont
will reach upper 80s for highs. The temperature will likely
remain steady or even fall slightly once the front passes your
location tomorrow.

Improved moisture return sets up for Friday night and continues into
Saturday. Best moisture stays mainly over the Piedmont, and will
also be helped by overrunning over top the low level wedge. The
better moisture and lift moves in on Saturday as the 850mb winds
increase and have kept likely PoPs over the Piedmont, tapering to
low chance at the coast. Even at the coast though, it will not be
terribly pleasant in the morning with onshore flow, low clouds
and the potential for drizzle into Saturday morning. Have
generally undercut the NBM highs for Saturday, especially
across the far NW. Highs will range from the mid 60s (or
possibly even lower) in the NW piedmont counties, to lower 80s
across the far south where some afternoon sunshine is possible.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
As of 905 PM EDT Thursday...

Key Messages...

- Additional scattered showers and storms on Sunday and Monday.

- A more summer-like pattern with warmer days and chances for
  late afternoon and evening showers and storms appears to be on
  the way for the middle of next week.

The backdoor front will attempt to move back north on Sunday as the
Ohio valley system approaches from the west. Showers may be more
widespread on Sunday due to a weak disturbance aloft lowering
heights across the region. Best moisture and still expected
along/west of I-95.  As such, have continued with likely/categorical
PoPs over the west on Sunday, tapering to chance PoPs at the coast.
Highs expected to be warmer than Saturday in the mid 70s to lower
80s, warmest SE VA/NC NC.

By Monday, the warm front will be well north of the area. However,
the system over the Ohio Valley will be moving through during the
day. Expect another round of showers/storms mainly during Monday
afternoon into Monday evening as a stronger upper disturbance moves
through in the W-NW flow aloft. Slightly more instability on Monday
vs Sunday so more thunderstorms are expected.

We get into an almost summertime pattern by Tuesday as the ridge
aloft builds overhead with afternoon/evening showers and
thunderstorms each day being triggered by the lee side trough. The
GFS and ECMWF both suggest the ridge breaks down slightly by Wed/Thu
with stronger 500mb flow of up to 50 kt by Wed afternoon. Along with
this, those models suggest weak short waves (likely of mesoscale
origin from convection over the Ohio Valley and central plains)
moving through the area. Although we are talking about days 6 and 7,
the relatively strong upper flow combined with relative steep mid
level lapse rates of up to 7 C/km would suggest the possibility of
severe weather. In fact, the CSU Machine Learning Probabilities
suggest a slight risk for severe weather on Wednesday and again on
Thursday. We have plenty of time to monitor this, but the area may
become a little more active by the end of next week.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
As of 150 AM Friday...

VFR conditions with light winds to begin the 06z TAF period,
with VFR conditions to prevail through the rest of the night. A
backdoor cold front dives southwest across the Maryland Eastern
Shore towards sunrise this morning, allowing winds to turn NE,
with MVFR conditions on the eastern shore tomorrow, especially
east of KSBY to KOXB. The front will continue to slowly move SW
today, perhaps reaching the other terminals by 18-20z. Some
scattered showers and perhaps even a thunderstorm will be
possible at KRIC and points west tomorrow afternoon into
tomorrow evening. Flight restrictions (primarily low CIGs) are
expected to spread to the other terminals starting late this
evening and last into Saturday.

Outlook...Sub-VFR conditions expected at times through through
the weekend and even into early next week due to an unsettled
weather pattern through Monday. A series of systems will cross
the region, with chances for rain/storms each day. A warmer,
more summerlike pattern returns by Tuesday with chances for
storms each afternoon/evening.

&&

.MARINE...
As of 300 AM EDT Friday...

Key Messages:

- Small craft advisories are in effect for the Chesapeake Bay
  and lower James River, and for the Ocean N of Parramore Island
  for today behind a backdoor cold front.

-Winds diminish a bit late tonight/Sat morning, but additional
 Small Craft Advisories may bee needed by lat Saturday/Saturday
 night.


Still rather quiet across the waters early this morning with SSW
winds of 10-15 kt or less and seas 2-3 ft N/1-2 ft S, with
waves in the Bay and rivers 1-2 ft (or less). The wind has
shifted to the NNE at buoy 44009 and into the Ocean zone from
the MD/DE border south towards Chincoteague. There may be a few
hrs worth of marine fog toward sunrise in these northern
Atlantic coastal waters before the winds increase, but do not
anticipate this being enough for a Marine Dense Fog.

Otherwise, E/NE winds increase abruptly later this morning as
cool/dry advection gets going behind the front with pressure
rises on the order of 4-5mb/6 hr. E-NE winds increase to 15-20
kt with gusts to around 25 kt, but will likely over- perform at
least across the northern coastal waters so have added the Ocean
zones N of Parramore to a Small Craft Advisory through 4pm this
aftn (with winds ~20kt gusting to 25 to near 30 kt), and seas
of 4-5 ft. The highest confidence in meeting small craft
criteria is in the southern bay/lower James, but the entirety of
the bay should at least see marginal SCA conditions. In the
Bay/James, SCA headlines remain in effect from later this
morning/aftn through 1 AM Sat morning. On the ocean S of
Parramore, wind gusts and wave heights on average should stay
below 25 kt with seas building to ~4ft. Should note that onshore
flow conditions tend to elevate seas a bit higher than
guidance, so will monitor the trends later this morning As of
now, will keep these zones out of any headlines. Easterly winds
subside some by Sat morning, but will remain around ~15 kt. Wind
speeds tick up again later Sat aftn/Sat night while shifting to
the SE. This brings another chance at SCA conditions, again
mainly over the Bay. Seas remain 3-4 ft with waves 2-3 ft in the
bay/rivers/sound.

The front lifts back N on Sunday, shifting winds to the S. SSW
winds return for Monday through the middle of next week (but
likely remain sub-SCA).

&&

.TIDES/COASTAL FLOODING...
As of 130 AM EDT Friday...

Tidal departures increase later today in response to the winds
turning onshore from the E or ENE. May consider a statement for
the lower Bay/lower James and for the upper Bay across the
northern Neck and perhaps Dorchester MD for the tide cycle this
evening/tonight depending on how the water levels respond.
Additional tidal flooding, mainly to minor flood thresholds
appears likely by later Sat through Sunday across the upper Bay
as winds become more SE to S. Moderate levels are not expected
(except perhaps locally at Bishops Head), so no Coastal Flood
Watches are anticipated.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 10 AM this morning to 1 AM EDT
     Saturday for ANZ630-631.
     Small Craft Advisory from 1 PM this afternoon to 1 AM EDT
     Saturday for ANZ632-634-638.
     Small Craft Advisory from 7 AM this morning to 4 PM EDT this
     afternoon for ANZ650-652.

&&

$$

SYNOPSIS...MRD
NEAR TERM...AM
SHORT TERM...MRD
LONG TERM...MRD
AVIATION...AM/MAM
MARINE...LKB/SW
TIDES/COASTAL FLOODING...