173
FXUS61 KAKQ 142020
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
420 PM EDT Sun Jul 14 2024

.SYNOPSIS...
Warm and humid tonight with isolated showers and thunderstorms
late this afternoon. A mainly dry and hot pattern develops
Monday through most of Wednesday. An unsettled period returns
late Wednesday through Saturday, as a cold front stalls across
the area.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 400 PM EDT Sunday...

Key Message:

- Humid with isolated to widely scattered showers and storms
  this aftn.

An upper ridge extends from the subtropical western Atlantic
into the Southeast this afternoon. Meanwhile, a weak upper
trough is moving across the Mid-Atlantic around the northern
periphery of the upper ridge. Meanwhile, a surface trough (and
dewpoint boundary) lingers from eastern PA SW into central NC.
This combined with the upper trough has resulted in the
development of isolated showers/tstms this afternoon.
Temperatures are primarily in the lower to mid 90s, with 80s a
the immediate coast. Dewpoints in the 70s E of the trough has
resulted in heat indices over 100F and some locations over 105F.
Any showers/tstms should dissipate early this evening. Mostly
clear, warm, and humid tonight with lows in the lower 70s W to
mid/upper 70s E.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
As of 400 PM EDT Sunday...

Key messages:

- Hot Mon-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 to build for Monday and 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 /20Z SUNDAY THROUGH FRIDAY/...
As of 200 PM EDT Sunday...

VFR as of 18z with FEW-SCT CU and generally a 5-10kt S to SW
wind inland and S to SE 5-10kt toward the coast (locally NE at
ORF). Isolated tstms are possible through 00z. Otherwise, VFR
conditions should prevail through Monday. Less fog is expected
late tonight/early Monday morning with more of a southerly low-
level flow.

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

&&

.MARINE...
As of 400 PM EDT Sunday...

Key Messages...

- Generally quiet marine conditions through Tue with southerly
  winds gradually increasing.

- South winds gusting to 20 kt are possible Wed/Wed evening
  ahead of a cold front.

Late this aftn, a sfc trough was located west of the waters.
Winds were SE or S 5-15 kt. Waves were 1-2 ft and seas were 2-3
ft. Winds will transition SE or S, to S tonight into Mon, as
the lee side trough will be located inland. As we move into
this week, expect the winds over the coastal waters to gradually
increase from 10-15 kt late Mon, to as high as 15-20 kt for Tue
night through Wed, due to the tightening pressure gradient
between the approaching cold front over the Ohio Valley, and the
Bermuda High to the SE of the area. Winds will stay 5-15 kt in
the Ches Bay and Rivers Mon into Tue, before increasing to 15
kt with a few gusts to 20 kt late Tue through Wed.

The cold front ends up stalling out over the area on Thu, but
gets a secondary push southward by Fri. It is still uncertain
if the front will clear the southern waters. However, the
consensus is that it will clear the northern waters allowing the
winds to turn NW or N. Regardless of where the front ends up,
expect diminishing winds starting Thu night, as the gradient
relaxes across the area.

Light winds should keep waves in the bay/rivers at a foot or
less. Southerly winds developing Mon, and slowly increasing
through Wed, will allow wind waves to gradually build with waves
of around 2 ft in the bay late Tue night into Wed evening, with
seas 3-4 ft over the ocean. Low Rip Risk for all the beaches for
Mon and Tue.

&&

.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 to 8 PM EDT Monday for MDZ021>024.
NC...Heat Advisory from 10 AM to 8 PM EDT Monday for NCZ012-013-030-
     102.
     Heat Advisory until 7 PM EDT this evening for NCZ013>015-
     030>032.
     Excessive Heat Warning from 10 AM to 8 PM EDT Monday for
     NCZ014>017-031-032.
VA...Heat Advisory from 10 AM to 8 PM EDT Monday for VAZ065-075>090-
     092-093-099-100-512>525.
     Excessive Heat Warning from 10 AM to 8 PM EDT Monday for
     VAZ095>098.
MARINE...None.

&&

$$

SYNOPSIS...AJZ/LKB
NEAR TERM...AJZ
SHORT TERM...AJZ/LKB
LONG TERM...AJZ/LKB/TMG
AVIATION...AJZ
MARINE...TMG/MRD
CLIMATE...AKQ