-- Discussion containing changed information from previous version are highlighted. --
641
FXUS61 KAKQ 291911
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
311 PM EDT Wed May 29 2024

.SYNOPSIS...
Mild and drier conditions are expected across the region
through late week, though some scattered afternoon showers or
thunderstorms will be possible over far northern portions of our
area into tonight. Pleasant and less humid conditions are
expected for Thursday through Saturday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 925 AM EDT Wednesday...

Key Messages:

- Scattered showers and storms possible across the north once
  again on Wednesday afternoon into Wednesday evening.

Morning GOES water vapor channels continue to show a relatively
compact but potent shortwave trough digging southeast from the
upper midwest into the western Ohio Valley. At the surface, a
~1000mb surface low pressure was analyzed over SE QC pushing
toward Atlantic Canada, with the associated cold front now
offshore of the eastern seaboard from New England to the coastal
Carolinas. To the west, a secondary or reinforcing cold front
is pushing from the upper midwest into the Ohio Valley. It is
this system that will bring another round of showers and storms
to the region later today. Temperatures are warming through the
lower to mid 70s this morning after morning lows that ranged
from the mid 50s to lower 60s.

The potent, compact upper shortwave and associated secondary
cold front to the west are still on track to dive SE across the
Ohio Valley into the central Appalachians this morning into the
afternoon, reaching the local area by early to mid- afternoon
into this evening. Expect this system will trigger another round
of isolated to scattered showers. Given the better forcing/shear
remaining just to our north, expect greatest coverage of
convection to be over the northern and northeastern tier of the
local area (mainly NE of the I-64 corridor). Cooler
temperatures aloft will allow for the development of some modest
instability (< 300-400 J/kg of MLCAPE) by the afternoon, while
deep-layer bulk shear and mid-level lapse rates increase
slightly. While the relatively weak shear will serve to limit
areal coverage to a degree, a multicell storm mode is favored,
with isolated to widely scattered showers expected. One or two
strong to severe storms remain possible, with gusty winds and
marginally severe hail the main threats. PoPs remain in the
30-50% range north of I-64, with slight rain chances south of
RIC metro to Hampton Roads/NE NC (kept the I-85 corridor into
interior NE NC dry for today, with these areas farther removed
from best forcing).

The cold front pushes offshore late tonight with high pressure
building across the region for Thursday and Friday. This will
bring dry and pleasant conditions for the latter portion of the
week. Highs in the upper 70s to low 80s NW, to mid 80s SE
sections. Lows tonight in the low to mid 50s inland, mid 50s to
around 60 coastal sections.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
As of 255 AM EDT Wednesday...

Key Messages:

- Pleasant and comfortable Thursday and Friday with temperatures
  at or just below normal. Highs mainly in the 70s to around 80,
  with lows in the 50s. A few readings in the 40s are possible
  well inland.

- Warming temperatures but remaining dry for Saturday.

The secondary cold front slides offshore Thursday morning. Cool,
dry Canadian high pressure builds across the region from
Thursday through early Saturday. Meanwhile, another shortwave
digs the upper trough south across the region Thursday into
Friday, with resultant NW flow aloft, keeping temperatures
cooler than normal both days. The upper trough pushes off the
mid- Atlantic coast Friday afternoon. Upper ridging on its heels
then builds across the eastern seaboard for the weekend, also
initiating a moderating temperature trend Saturday that will
continue into early next week.

Highs Thursday and Friday are generally in the 70s, with dewpoints
only in the upper 40s to lower 50s under a partly to mostly
sunny sky. Lows Friday morning potentially drop into the upper
40s for the Piedmont, with 50s for most of the area, and around
60F far SE. Highs Saturday in the upper 70s to around 80, with
lows early Sunday in the 50s to near 60.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 255 AM EDT Wednesday...

Key Messages:

- Gradually warming temperatures return Sunday into early next
  week.

- Low rain chances return with typical late day and evening
  showers and storms possible both Sunday and Monday.

The upper ridge builds across the east coast late in the
weekend into early next week, as surface high pressure settles
offshore. This will bring mainly dry conditions and a continuing
trend of moderating temperatures. A dampening trough tries to
push over the top of the ridge Sunday into early next week, but
PoPs are no higher than climo (15-20%) at this time. Highs
trend back into the mid 80s by SUnday, with mid to upper 80s
into early next week. Lows mainly in the 50s to begin the
medium range period, moderating back into the 60s into early
next week.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
As of 220 PM EDT Wednesday...

An upper trough is approaching from the NW as of 18z. Isolated
to scattered showers and a few tstms are developing across the
area in advance of the trough, with SCT-BKN CU with bases of
5-7kft. The wind is generally SW 5-10kt inland, and NE to SE
along the coast. Isolated to scattered showers/tstms are
expected to pass across the region through about 02z, with some
lingering activity along the coast through 04-06z. VFR
conditions are expected to prevail with brief sub-VFR
conditions possible with a direct impact at any given terminal.
Locally strong wind gusts are also possible. Shower/tstm chances
are highest at SBY (40-50%), 30-40% at RIC, 20-30% at PHF/ORF,
and ~20% at ECG. Drier air arrives later tonight behind a cold
front. Mainly VFR Thursday with a NNW wind of 8-12kt (gusts to
near 20kt toward the coast) with SCT-BKN aftn CU, and a slight
chc of showers inland as another upper trough tracks across the
region.

A slight chc of showers lingers into Thursday evening across
southern VA and NE NC. Otherwise, high pressure builds across
the region Thursday night through Saturday, before sliding
offshore Sunday into Monday. Dry and VFR conditions are expected
to prevail Thursday night through Monday.

&&

.MARINE...
-- Changed Discussion --
As of 300 pm EDT Wednesday...

Key Messages:

- Showers/storms with gusts of up to 40 kt expected to move NW to SE
across the waters late this afternoon and early evening.

- Cold frontal passage tonight may allow some gusts to 20 kt late
tonight into Thursday morning.

- Tranquil marine weather for this coming weekend.

Showers and storms over northern VA as of 230 pm are forecast to
move across mainly the northern waters late this afternoon into
early this evening. It is certainly conceivable that these
storms could produce brief gusts to 35 or 40 kt later this
afternoon and early this evening. In fact, Dulles just reported
a gust to 37 kt. These gusts will be very brief (less than 30
min) and they will be handled by special marine warnings if
needed.

The actual cold front moves across the waters late this evening,
with high pressure building in immediately behind it. Guidance wind
speeds have bumped up slightly across the central Chesapeake Bay
after 09z. As such, have opted to issue a small craft advisory for
those areas late tonight into Thursday for north winds of 15-20 kt.
Winds will subside Thursday afternoon to 10 to 15 kt before
increasing again to 15 to 20 kt on Friday due to another surge ahead
of the high pressure center over the Ohio Valley. Outside of the
gusty shower or storm, seas will generally be 2 feet tonight
building to 2 to 3 ft on Thursday and Friday. Waves 1 to 2 ft in the
bay tonight, building to 2 ft on Thursday and Friday.

Fairly tranquil marine weather is expected this weekend into early
next week. High pressure centered over the Middle Atlantic on
Saturday will slowly shift offshore by Monday. This will allow north
to northwest winds of 10 kt to shift to the south or southeast on
Monday. Winds will also increase to 15 kt on Monday as the pressure
gradient tightens over the area between the high to the east and
developing low pressure west of the Appalachians. Models are in
disagreement in the timing, but they all show some type of boundary
moving through the region Tuesday or Wednesday. This will allow
southerly winds and seas to perhaps increase to small craft advisory
criteria but there is too much uncertainty to include this in the
forecast at this time.

Seas of 2 to 3 feet on Saturday will build to 4 to 5 ft by later
Sunday into Monday due to the increased southerly wind.
-- End Changed Discussion --
&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 5 AM to 5 PM EDT Thursday for ANZ630-
     631.
-- End Changed Discussion --

&&

$$

SYNOPSIS...MAM
NEAR TERM...AJZ/MAM
SHORT TERM...AJZ/MAM
LONG TERM...AJZ/MAM
AVIATION...AJZ
MARINE...MRD