-- Discussion containing changed information from previous version are highlighted. --
207
FXUS61 KAKQ 261108
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
708 AM EDT Wed Jun 26 2024

.SYNOPSIS...
High pressure slides farther offshore today. A cold front
approaches the area later this afternoon and crosses the region
tonight into Thursday, bringing the a chance for showers and
thunderstorms. High pressure builds north of the region for the
latter portion of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 345 AM EDT Wednesday...

Key Message:

- Heat builds again today and heat indices likely exceed 100F
  again.

- Scattered showers and thunderstorms develop late this
  afternoon into Wednesday night, with a few storms potentially
  being strong or severe with damaging wind gusts to primary
  threat.

GOES water vapor channels depict an upper ridge over the
central CONUS with quasi-zonal flow from the Ohio Valley to the
Northeast at the base of a broad trough over the northern Great
Lakes. At the surface, high pressure is centered off the
Carolina coast and prevails locally. Mostly clear early this
morning with temperatures in the 70s and a SSW wind of 5-10 mph.
The trough over the Great Lakes will dig SE today into this
evening pushing a cold front into the Ohio Valley. The low-level
flow increases out of the SW today, allowing 850mb temperatures
to surge to 20-22C ahead of the cold front. This supports high
temperatures in the mid 90s to near 100F. Dewpoints should mix
out during the day and drop into the mid to upper 60s (perhaps
even a degree or two lower) during peak heating. So while
temperatures will be near 100F, heat indices will generally
range from 100-104F. Mostly sunny through mid-afternoon and then
becoming partly sunny with a SW wind of 10-15 mph.

Forecast soundings show that the boundary layer remains capped
much of the day prior to some height falls arriving later this
afternoon into tonight. 00z/26 CAMs continue to develop
scattered tstms in the higher elevations of W/NW VA by 3-4 PM
before trying to push SE into NW portions of the FA. The highest
tstm chances will be from 5 PM-1 AM mainly north of I-64 as the
actual front nears the area before the convection gradually
weakens early Thursday morning. Locations south of a Farmville-
Richmond-Williamsburg line will likely see little to no rain
through Thursday morning, with localized totals in excess of 1"
possible from Louisa County to the MD Eastern Shore. In
addition, any storm will be capable of producing damaging wind
gusts given very strong sfc heating, a deep well mixed boundary
layer, and some mid-level drying. In fact, forecast soundings
from most models show DCAPE values of 1200-1500 J/kg Wed
aftn/evening. The Day 1 convective outlook from SPC is very
similar with only a slight nudge southward of the slight and
marginal risk areas. Convection diminishes in coverage
overnight. However, some convection will linger overnight with
some instability and the front settling over the area. Lows
tonight will mainly be in the upper 60s to mid 70s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
As of 345 AM EDT Wednesday...

Key Messages:

- A few thunderstorms are possible across SE VA/NE NC Thursday
afternoon-evening.

The cold front slowly pushes south across southern VA and NE NC
Thursday as high pressure and a drier airmass build into the
northern tier of the area. Showers/tstms are expected to
redevelop along the boundary Thursday afternoon with the highest
chc across SE VA and NE NC. High temperatures return to
seasonally hot levels ranging from the mid 80s to near 90F.
Shower/tstms largely dissipate or move to our south by late
Thursday evening, although some isolated activity could linger
into the early overnight hours over southern VA. High pressure
builds across New England Thursday night into Friday following
the frontal passage. Lows Thursday night fall into the mid
60s-lower 70s. Easterly flow Friday will keep highs in the lower
to mid 80s along the coast, and seasonally hot inland with
highs in the upper 80s to around 90F.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 345 AM EDT Wednesday...

Key Messages:

- Heat rebuilds across the region Saturday and Sunday and
potentially more humid.

- Scattered showers and thunderstorms are possible later Sunday
  afternoon into Sunday night ahead of a cold front.

Surface high pressure initially settles off the coast Friday
night into early Saturday, with some moisture returning as a
weak warm front lifts through the area. Therefore, there is a
slight chc to low chc of showers and perhaps a tstm from central
VA and the Piedmont to the MD Eastern Shore Friday night into
early Saturday morning. Lows Friday night are mainly in the
upper 60s to mid 70s. Otherwise, the heat builds back over the
local area this weekend as high pressure settles off the
Southeast coast. Another upper trough and cold front approach
the area from the NW late this weekend, and the cold front is
progged to cross the area Sunday night. Forecast high
temperatures are mainly in the mid 90s on both Saturday and
Sunday, with aftn dewpoints in the lower to mid 70s (mid 70s
mainly toward the coast) during peak heating on both days. This
is supported by the deterministic guidance and MOS guidance, but
is below the mid/upper 70s shown by the NBM (which is likely
too high especially given how dry it has been). Resultant heat
indices are in the upper 90s to lower 100s Saturday, and then
potentially 105-109F for much of the CWA Sunday. Isolated to
widely scattered tstms are possible on Saturday afternoon
(mainly W of I-95), with a better chc of showers/tstms later
Sunday afternoon into Sunday night as the cold front drops
through the region. A slight reprieve in the heat is possible
early next week in the wake of the cold front as the 00z/26 EPS
and GEFS each depict below average 850mb temperature anomalies
Monday and Tuesday. However, the ensemble guidance also surges
the heat back into the region by the middle of next week just
prior to Independence Day.

&&

.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
As of 705 AM EDT Wednesday...

High pressure is centered off the Carolina coast as of 11z.
Mainly VFR under some this cirrus with a S to SSW wind of
5-10kt. The exception is some patchy IFR stratus around ORF
that should dissipate around 12z. VFR today with SCT aftn CU
with bases of 5-7kft. The wind will be SSW of 8-12kt with
occasional gusts to ~20kt. A cold front approaches from the NW
later this afternoon and drops into the region tonight. There is
a 40-60% chc of late aftn/evening showers/tstms for RIC and
SBY, with a 15-30% chc of showers/tstms and ORF, PHF, and ECG
tonight. A few tstms could produce strong wind gusts along with
brief flight restrictions in heavy rain. Overall coverage of
showers/tstms diminishes after midnight. The latest guidance
depicts the potential for some stratus late tonight/early
Thursday morning.

This front will be slow to push through southern VA and NC NE
Thursday with a 30-50% chc of redeveloping aftn/early evening
showers/tstms. High pressure and dry conditions return Friday
into Saturday. A chance for showers/tstms again later Sunday.
-- End Changed Discussion --

&&

.MARINE...
As of 415 AM EDT Wednesday...

High pressure will slide farther out to sea today. Early this
morning, winds were SW 5-15 kt with gusts up to 25 kt in nrn
portions of the waters. SCAs remain in effect for the 630/631
zns of the Ches Bay until 7 am. SW winds mainly 5-15 kt later
this morning, will become S and increase to 10-20 kt with gusts
up to 25 kt by late this aftn into this evening in advance of a
cold front. Waves will build to 2-3 ft in the Bay, and seas will
build to 3-4 ft in the coastal waters. 4-5 ft seas will be
possible for a brief period north of Parramore Island. So, will
likely have SCA conditions again near the mouth of the Bay, and
portions of the coastal waters from early this evening to around
midnight. That weakening cold front will push through the region
late tonight into Thu aftn. NE winds expected late Thu night
through Fri morning, then E and SE winds for Fri aftn into Sat
morning, as high pressure slides by to the north then off the
srn New England coast. Low rip current risk is forecast for
all beaches today and Thu.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 5 PM this afternoon to 1 AM EDT
     Thursday for ANZ634-650-652-654-656.
-- End Changed Discussion --

&&

$$

SYNOPSIS...AJZ/ERI
NEAR TERM...AJZ/ERI
SHORT TERM...AJZ/ERI
LONG TERM...AJZ/ERI
AVIATION...AJZ
MARINE...JDM/TMG