-- Discussion containing changed information from previous version are highlighted. --
426
FXUS61 KAKQ 221802
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
202 PM EDT Sun Sep 22 2024

.SYNOPSIS...
High pressure builds south along the Mid-Atlantic coast into
early next week. Meanwhile, a series of shortwave troughs will
slide across the region in northwest flow aloft bringing on and
off rain chances. Seasonal temperatures are expected to start
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 940 AM EDT Sunday...

Key Message:

- A backdoor cold front brings cloudy conditions and isolated
  showers.

Persistent low pressure continues to spin well offshore to the NE
this morning. Meanwhile, a weak backdoor cold front has pushed
into central VA. Aloft, NW flow continues over the FA with the
trough offshore and a broad ridge to the W. Spotty showers over
the Eastern Shore have diminished in coverage and pushed
offshore. Some patchy fog persists inland, but visibility has
improved at most locations. Temperatures are mainly in the upper
60s to around 70F under a mostly cloudy to overcast sky, with
some partial clearing over the interior of the MD Eastern Shore
and interior NE NC.

The backdoor front will drift SW through the day bringing cloudy
conditions and isolated showers. Have kept PoPs to 15-20% for most
of the day. Low clouds will persist over much of the area for most
of the day, but may start to scatter out some closer to sunset,
especially closer to the coast. Highs today will range from the mid-
70s in the NE to around 80 in the SW. Lows tonight will be on either
side of 60.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
As of 355 AM EDT Sunday...

Key Messages:

- Pleasant start to the week with dry weather and highs in the
  70s

- Low end chances for showers on Tuesday.

Sfc low pressure offshore will finally make some progress on its
journey S Mon into Tuesday. Meanwhile, high pressure centered well
to the N will build down the E coast. The ridge aloft slides east
early week, its axis sliding in overhead late Monday/early Tuesday.
The ridge looks to amplify along the coast mid week as a trough
deepens over the Plains. Mon looks to be dry locally (albeit
cloudy), but a shortwave trough approaching the region may bring
chances for showers on Tues. However, high pressure at the coast may
limit rain to western counties. Have Chc PoPs W of I-95 on Tues and
SChc to the E. Temps on Mon look pleasant with highs in the mid to
upper 70s. Temps don`t look terribly different Tues, but thick cloud
cover and higher rain chances may keep highs around 70 in the NW.
Lows Mon and Tues night will be in the low 60s.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
As of 355 AM EDT Sunday...

Key Messages:

- Multiple low-end chances for precip next week.

The ridge aloft will slide offshore Wed as the trough moves into the
Upper Midwest. SW flow will bring more moisture into the area, and a
series of weak shortwaves will yield several opportunities for rain.
Confidence is low, however, given disagreements between the global
models on how to handle the UL trough and the potential tropical
system in the Gulf. Stuck generally to NBM for PoPs given this
uncertainty which gives widespread Chc PoPs Wed and Thurs. Could
also see showers Fri/Sat, but only have SChc these days. Highs will
be similar Wed-Fri with upper 70s-low 80s in the SE and mid-70s in
the NW.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
As of 200 PM EDT Sunday...

High pressure continues to be centered over Atlantic Canada as
of 18z and is ridging SW along the Mid-Atlantic coast.
Meanwhile, a backdoor cold front has pushed through the area.
Cigs are primarily MVFR with an ENE wind of 5-10kt. Cigs are
expected to slowly improve to VFR through the aftn with some
clearing by this evening, especially toward the coast. MVFR/IFR
cigs are expected to develop inland late tonight into early
Monday morning with the best likelihood of flight restrictions
at RIC. Additionally, vsby potentially falls to 3-5sm at RIC.
High pressure remains in vicinity of the coast Monday. Dry and
VFR Monday late morning into the aftn with increasing clouds as
an upper level impulse approaches from the NW. The wind will be
SE 5-10kt inland and ENE 5-10kt along the coast.

There is a chc of showers Monday night into Tuesday, especially
well inland away from the coast. Minimal chcs of showers persist
Tuesday through Friday. Generally VFR outside of any late
night/early morning fog/stratus.
-- End Changed Discussion --

&&

.MARINE...
As of 400 AM EDT Sunday...

Key Messages:

- Small Craft Advisories remain in effect for all coastal waters
through Monday (primarily for seas).

- Winds increase Sunday, but remain mainly sub-SCA. Waves may  build
to 4 ft late Sunday/Sunday night at the mouth of the  Bay.

- Persistent long period swells keep seas elevated into the   middle
of next week.

Sfc low pressure (~1004mb) lingers well off the northeastern coast
of the United States, with a 1022mb+ high pressure centered well to
the north, across northern Quebec and New Brunswick. Southeast winds
~10 kt (10-15 kt across the central and northern bay zones continue
into this morning. Winds become more easterly this afternoon 10-15
kt with perhaps a few gusts to around 20 kt. This is due to a weak
surface low which moves southeast across Virginia into eastern North
Carolina. Northeasterly winds 15-20 kt are expected across the
coastal waters and the lower bay. Sunday evening winds are expected
to decrease  to 10-15 kt. Across the bay waves are expected to grow
between 1-2ft (2-3ft occasional 4ft at the mouth of the bay) later
this afternoon and into the evening. Expect the north coastal water
seas to grow to 4-6ft and southern coastal waters 4-5 ft later this
afternoon and evening. Through this week expect the coastal waters
waves heights to slowly grow as a strong high pressure continues to
build in. Right now, small craft advisories remain in place
across the coastal waters til Monday. Possibly expect them to
remain in place through this week as seas build. Will note, at
this time confidence still remains too low for any headlines
(outside of 3-4 ft waves at the mouth of the Ches Bay). Real
time analysis and Model trends will continued to be monitored if
a headline needs to be issued for this zone.

&&

.TIDES/COASTAL FLOODING...
As of 430 AM Sunday...

- Key Message: Long duration coastal flood event continues
  across the region, with water levels expected to peak today
  and Monday. At least minor flooding is likely to persist
  through Tuesday, possibly into Wednesday in portions of the
  mid/upper Bay. Various headlines remain in effect (see latest
  CFWAKQ for details).

Tidal departures are currently running +1.5 ft to +2.0 ft above
astro tide levels. The high tides later today and and Monday
afternoon/evening look to be slightly higher than what has
occurred over the past 24hrs and as such, expect additional
rounds of moderate coastal flooding through Monday evening.

In general, the most widespread moderate flooding (potentially
near Major at a few places) will be over the mid/upper Bay,
including the tidal Potomac/Rappahannock and the MD eastern
shore through Monday evening. These locations may see moderate
coastal flooding continue into Tuesday as winds veer to the E-SE
and long period easterly swell remains in place over the ocean,
allowing water trapped in the Bay to shift northward.

Areas to the south across the lower Bay/tidal James and York
rivers will be more marginal, with peak water levels mostly in
high end minor flood thresholds or briefly touching moderate
thresholds. Have left the Warnings in effect in these areas but
did not extend these through Monday given low confidence.

Have opted to leave Norfolk and Chesapeake in a Coastal Flood
Advisory (as opposed to a Coastal Flood Warning) given that the
Elizabeth River and Sewell`s Point still look to remain below
moderate flood stage. A Coastal Flood Advisory also remains
across the Atlantic side of the Maryland Eastern Shore with
Ocean City looking to remain in minor flood stage through Monday
afternoon.

Additional headlines are likely to be needed for Tuesday, but
given uncertainty with respect to these being Warnings or
Advisories, did not extend the current headlines beyond Monday
night for now.

In addition, a High rip current risk is in effect through
Sunday and will likely be extended into Monday as well.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...Coastal Flood Warning until 2 AM EDT Tuesday for MDZ021>023.
     Coastal Flood Advisory until 4 PM EDT Monday for MDZ024-025.
NC...Coastal Flood Warning until 4 PM EDT this afternoon for NCZ102.
VA...Coastal Flood Warning until 4 PM EDT this afternoon for VAZ098.
     Coastal Flood Warning until midnight EDT Monday night for
     VAZ075-077.
     Coastal Flood Warning until 10 PM EDT Monday for VAZ076-078-
     085-089-090-093-096-521-522.
     Coastal Flood Advisory until 8 PM EDT Monday for VAZ083-518-
     520.
     Coastal Flood Warning until 6 PM EDT this evening for VAZ084-
     086-523>525.
     Coastal Flood Advisory until 6 PM EDT Monday for VAZ095-097.
     Coastal Flood Warning until 8 PM EDT Monday for VAZ099-100.
MARINE...Small Craft Advisory until 1 AM EDT Monday for ANZ634.
     Small Craft Advisory until 6 AM EDT Tuesday for ANZ650-652-654-
     656-658.
-- End Changed Discussion --

&&

$$

SYNOPSIS...AJZ/TMG
NEAR TERM...AJZ/AM
SHORT TERM...AM
LONG TERM...AM
AVIATION...AJZ
MARINE...HET/LKB
TIDES/COASTAL FLOODING...