391
FXUS61 KAKQ 150759
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
359 AM EDT Mon Jul 15 2024

.SYNOPSIS...
A very hot stretch of weather prevails today through most of
Wednesday. An unsettled period returns late Wednesday through
Thursday, as a cold front pushes through the area and stalls
across the Carolinas. Shower chances focus mainly over southern
Virginia and North Carolina Friday, then return to all zones by
Saturday.

&&

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

Key Message:

- Hot and humid east, hot and slightly less humid west.

- Excessive Heat Warning in effect SE zones (added
  Bertie/Hertford NC to the Warning).

- Heat Advisory in effect for most of the remainder of the area
  except the piedmont and MD beaches (added Caroline/western
  Hanover to the Advisory).

The latest analysis indicates a weak sfc trough over the region
(actually a bit of a sfc low over Maryland). Aloft, a westerly
flow prevails with a broad trough across central and eastern
Canada, and a broad ridge from the Four corners region extending
east to the SE CONUS. Warm and humid this morning with
temperatures in the mid 70s to around 80F and dew pts in the
70s. With the sfc low to the N, enough mixing with a SW low
level wind has inhibited any fog development and the sky is
mostly clear. A few isolated/widely scattered showers/storms
may develop again this aftn with the highest PoPs to ~30% over
the far NW for storms developing on the mountains drifting east,
and across NE NC where the highest low level moisture will
reside. The primary concern for today will be the heat/humidity.
Yesterday, the dew pts stayed on the higher edge of guidance
over RIC metro, but today we expect to see deeper mixing and
even the typically high bias guidance (NAM/NBM),show dew pts
dropping at peak heating this aftn along and W of I-95. With
that said, highs in the upper 90s to around 100F are expected,
so have decided to expand the Heat Advisory slightly west to
include Caroline and all of Hanover, and to expand the Excessive
Heat warning a tier W into Bertie/Hertford NC. Overall, a very
hot day expected with record highs possible (see climate section
for details). Any convection this aftn should quickly wane after
sunset, with mostly clear skies overnight. Lows will be mainly
in the mid to upper 70s with a few urban areas perhaps not
dropping below 80F. Will allow dayshift to determine if the
Excessive Heat Warning in the SE will be extended through the
night and through Tuesday (a good chc that Tuesday is even worse
so Excessive Heat may need to expand west at least a tier or two
of counties).





&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
As of 400 PM EDT Sunday...

Key messages:

- Hot Tue with high humidity closer to the coast and slightly
  lower humidity well inland (Tue probably the hottest day).
  Heat Advisory for most areas outside of the NW Piedmont Monday
  with Excessive Heat Warnings from the northern shore f the
  Albemarle Sound to southside Hampton Roads. At least Heat
  Advisories likely, with Excessive Heat Warnings possible E of
  I-95 Tuesday.

- Remaining hot Wednesday and humid area-wide but with a higher
  coverage of storms by afternoon (heat headlines possible but
  more uncertain)

Heat continues Tuesday, as a broad upper ridge expands east
from the desert SW to the SE CONUS. With the consensus being for
850mb temperatures rising to 20-22C Mon aftn, highs should
easily climb into the mid 90s at the coast, with upper 90s/near
100F inland. The models all do show some degree of dew pts
dropping into the upper 60s/near 70F in the aftn across inland
areas where the highest temps are expected. However, dewpoints
have remained stubbornly high today even in the lower to mid 70s
from the SW Piedmont through the RIC metro, so dewpoints may
struggle to mix down fully for most areas aside from the
Piedmont. Closer to the coast Monday, dew pts likely stay in the
mid 70s through the aftn, leading to peak heat indices 105-110F
east of I- 95, with 100-105F in the Piedmont. A heat advisory
has been issued for most areas outside of the Piedmont W and NW
of the RIC metro (and the MD beaches). An excessive heat warning
has been issued from the northern shore of the Albemarle Sound
to southside Hampton Roads where heat indices are locally
forecast to reach 110-112F.

Other than a stray PM tstm moving east off the Blue Ridge into
the eastern Piedmont or a seabreeze tstm developing over NE NC,
will keep remaining areas dry Monday. Warm/muggy Monday night
with lows ranging through the 70s. Likely a degree or two hotter
on Tue across the region with highs in the mid/upper 90s to
around 100F. At least a Heat Advisory will likely be needed for
the entire area, with an Excessive Heat Warning possible in some
locations, especially east of the I-95 corridor and away from
the immediate Atlantic coast. The models remain in decent
agreement that Wednesday will be the last day of hot conditions
as the upper ridge eventually breaks down, as a strong upper
trough translates SE from north central US to the Great Lakes.
Dew pts will be slightly higher Wednesday than Tuesday (in the
lower to mid 70s inland with mid to upper 70s SE), due to
moisture pooling along a pre-frontal trough. Highs will be a few
degrees less Wednesday (mid-upper 90s) but the higher dew pts
may lead to similar heat indices with 110F+ possible in the E
and SE. Isolated tstms will be possible by early aftn, with
scattered showers/tstm developing by mid aftn and beyond.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 400 PM EDT Sunday...

Key Messages:

- A cold front moves in from the NW late Wed/Wed night, slowly
  moving through much of the area Thu, then stalling near or
  just south of the area Fri/Sat bringing and increased chance
  of showers and thunderstorms.

12z/14 models remain in fairly good agreement that the upper
level trough pushes from the Great Lakes to New England
Wednesday night through Thursday, but flattens out to the south
as it approaches the strong/persistent upper level ridge
anchored well offshore of the SE US coast. The consensus is for
the upper ridge to retrograde west and become centered closer to
the SE US coast into next weekend. Will have the highest
chances for showers/storms across the NE Wednesday night, with
all zones getting likely PoPs (~60%) Thursday as the front
slowly pushes south towards NC. Locally heavy rainfall will
certainly be possible during this timeframe. Highs Thursday will
mostly be highly dependent upon the timing of the front, for
now expecting mid 80s to near 90F. Not as hot, but still humid
Friday-Saturday with highs mostly in the low- mid 80s. Friday
may see some drier air push into northern portions of the FA as
broad sfc high pressure builds east from the Great Lakes. As the
upper levels ridge moves closer to the SE coast Saturday, the
flow aloft increases from the SW and expect to see more humid
air even into northern zones by that time. Given uncertainty as
to the exact timing and placement regarding the front, remained
a little below NBM PoPs for Friday-Saturday, 20-30% north to
40-50% south (which is still above climo for most of the area).

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
As of 745 PM EDT Sunday...

VFR conditions should continue through the 00z TAF period. Tstms
near ECG have moved well to the SE and should eventually
dissipate. Clear outside of high clouds tonight with SCT cumulus
developing Mon aftn. Could see isolated-widely scattered tstms
NW of RIC later Mon aftn into the evening, but confidence is
very low that the tstms will actually reach RIC (PoPs ~15%).
Winds will remain S-SSW with speeds below 12 kt.

VFR conditions continue Monday night through early Wednesday.
Shower/tstm chances increase Wednesday aftn through Friday with
periodic flight restrictions expected ahead of a slow moving
cold front.

&&

.MARINE...
As of 315 AM EDT Monday...

Key Messages...

- Generally quiet marine conditions expected today and Tuesday
  with increasing SW winds expected ahead of a cold front
  Wednesday into Thursday.

Surface ridge remains anchored off the SE CONUS with weak lee
troughing noted over inland portions of the local area. Flow aloft
is weakly zonal with strong ridging over the Four Corners and the
main jet displaced well to the north along the US/Canadian border.
Winds are SW 10-15 kt this morning over the waters. Waves in the
Ches Bay are 1-2 ft with seas 2-3 ft.

Inland lee trough will be quasi-permanent through the first
half of the week as flow aloft remains zonal. Expect sub-SCA S
and SW winds today and Tuesday. A cold front drops southward
Wednesday into Thursday with a modestly increasing pressure
gradient ahead of the boundary. For now, will show winds staying
below SCA thresholds, generally ~15 kt in the rivers, sound,
and bay with 15-20 kt offshore. Guidance does show the potential
for seas to build to 4-5 ft in SW flow late Wednesday into
early Thursday for our northern coastal waters but NWPS tends to
over estimate seas in SW flow. The cold front is forecast to
settle southward on Thursday but likely stalls somewhere near
the VA/NC border. The front resumes southward movement on Friday
with winds becoming NE ~10 kt behind the boundary.

Low rip current risk today and Tuesday at all area beaches.

&&

.CLIMATE...
Record Highs and record high mins may be challenged Mon-Wed.

- Record Highs:

- Site: Mon 7/15    Tue 7/16    Wed 7/17

- RIC:  100 (1995)  101 (1980)  100 (1980)
- ORF:  101 (1995)  102 (1879)  100 (1887)
- SBY:  100 (1995)   99 (1915)   99 (2012)
- ECG:   97 (1997)   98 (1995)   99 (1942)

- Record High Mins:

- Site: Mon 7/15    Tue 7/16    Wed 7/17

- RIC:   77 (1993)   77 (1983)   76 (2005)
- ORF:   82 (1992)   80 (1995)   80 (2021)
- SBY:   79 (1995)   78 (2013)   80 (1983)
- ECG:   78 (1993)   79 (2012)   80 (2019)

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for MDZ021>024.
NC...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for NCZ012-102.
     Excessive Heat Warning from 10 AM this morning to 8 PM EDT
     this evening for NCZ013>017-030>032.
VA...Heat Advisory from 10 AM this morning to 8 PM EDT this evening
     for VAZ064-065-075>090-092-093-099-100-511>525.
     Excessive Heat Warning from 10 AM this morning to 8 PM EDT
     this evening for VAZ095>098.
MARINE...None.

&&

$$

SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...AJZ/LKB
LONG TERM...AJZ/LKB/TMG
AVIATION...ERI/LKB
MARINE...RHR
CLIMATE...