-- Discussion containing changed information from previous version are highlighted. --
980
FXUS61 KAKQ 230755
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
355 AM EDT Mon Sep 23 2024

.SYNOPSIS...
High pressure builds south along the Mid-Atlantic coast early
this 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 this
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 315 AM EDT Monday...

Key Message:

-Cloudy, but overall pleasant day with highs in the 70s.

-A chance for showers tonight, especially west of I-95.


Early morning sfc analysis indicates high pressure centered over New
England/Eastern Canada ridging down the Atlantic coast and into the
local area. Meanwhile, persistent low pressure well offshore is
finally making progress on its journey south. Aloft, a ridge is
nudging into the local area. Through the day today, the ridge axis
aloft will slide in overhead while the sfc high continues to wedge
itself down the coast.

Cloud cover has been a little slow to build back in from the west
tonight. As a result, temps are running a bit cooler than
anticipated between I-95 and the immediate coastal area. Latest obs
show these locations in the upper 50s. Further inland, where clouds
have filled in, temps are in the low-mid 60s. A few obs are showing
fog, but this shouldn`t be as widespread as yesterday morning.
Clouds will stick around through the day, especially inland. Due to
the thicker cloud cover, temps will run on the cooler side with
highs in the low to mid 70s. Warmer in the east with highs in the
mid-upper 70s. Onshore flow continues today, so immediate coastal
areas will also run on the cooler side. Regarding precip, the
daytime hours should largely remain dry, but cannot completely rule
out a stray shower on the western edge of the FA. A weak shortwave
trough will travel up the ridge aloft tonight, which may act to
trigger showers in the area. However, high pressure at the coast
will act to limit precip, especially E of I-95. Have Chc PoPs
entering the western counties late this evening and sticking around
through the night. Lows tonight will be in the low-mid 60s.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
As of 330 PM EDT Sunday...

Key Messages:

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

- Low end chances for showers Monday night into Tuesday and
  again Wednesday.

Low pressure slides SE well off and farther away from the coast
Monday into Tuesday as the upper ridge builds SE into the
Southeast CONUS. Surface high pressure centered well NE of the
region will continue to build SW along the coast. Mainly dry
Monday, although a shortwave trough will bring a chc of showers
Monday night into Tuesday, and a slight chc of tstms Monday
evening and Tuesday afternoon and evening over the Piedmont.
High pressure at the coast will generally confine rain chances
to the western half of the area. The upper ridge amplifies off
the Southeast coast Wednesday. However, our western and northern
counties will still be close enough to the northern periphery
of the ridge for a chc of showers (and a slight chc of tstms) to
continue. There will be a considerable amount of cloud cover
Monday through Wednesday, especially NW. Highs Monday will
mainly be in the mid to upper 70s. Thicker cloud cover has the
potential to keep the NW counties in the upper 60s to around 70F
Tuesday, with lower to mid 70s elsewhere. By Wednesday, highs
push into the mid 70s NW to the lower 80s SE as the upper ridge
amplifies. Lows will mainly be in the 60s Monday through
Wednesday mornings.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 330 PM EDT Sunday...

Key Messages:

- Multiple low-end chances for precip late next week into early
  next weekend with low confidence in regard to the eventual
  evolution of a tropical system in the Gulf of Mexico.

There is an increasing chc of tropical development in the NW
Caribbean and Gulf of Mexico Monday through Wednesday. However,
there is low confidence on how the potential system and mid-
latitude jet interact by late week into next weekend. The
general trend amongst the 12z/22 models is for the tropical low
to move into the mid-South while an upper low dives SE off the
New England coast, and high pressure nudges into the northern
Mid-Atlantic. This would generally keep much of the moisture SW
of the area, with some rain trying to nudge in from the SW
Friday into Saturday. At this time, PoPs are generally at or
below 20% for the late week into next weekend (highest SW albeit
still low), with seasonal high temperatures in the mid 70s to
around 80F and lows in the upper 50s to mid 60s.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
As of 150 AM EDT Monday...

VFR conditions prevail across the terminals to start the 06z
TAF period as high pressure ridges down the Atlantic coast.
While cloud cover is still expected to increase later tonight,
there is less confidence regarding flight restrictions at RIC
and whether or not the thicker cloud cover will make it to the
coast. Guidance now keeps MVFR/IFR west of RIC tonight. Did not
completely remove the MVFR from the TAF, but have trended it
toward less impact. Elsewhere, not expecting flight restrictions
within the TAF period outside of brief, shallow ground fog.
Winds look to remain light through the period and generally out
of the E.

There is a chc of showers late Mon evening into Tue, esply well
inland away from the coast. Minimal chcs of showers persist Tue
through Fri. Generally VFR/MVFR outside of any late night/early
morning fog/stratus.

&&

.MARINE...
-- Changed Discussion --
As of 345 AM EDT Monday...

Key Messages:

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

- Persistent long period swells keep seas elevated throughout
this week.

-Northeast winds may become elevated next weekend.

A strong surface low pressure continues to linger far off the
eastern United States, with a strong high pressure (1022mb) over
north eastern Canada early this morning. As of 3:30 this morning
winds are gradually out of the east northeast around 10-15 kt with
occasional gusts in upwards of 20 kt. The winds today will stay
between 5-10 kts across the bay with occasional gusts up to 15 kt.
Across the ocean winds will be slightly higher with sustained winds
between 10-15 kt and occasional gusts in upwards of 20 kt. After
this afternoon winds will begin to diminish over all waters later
this evening. Winds remain sub SCA level (mainly SE) through Thu
before becoming NE Fri. Models are coming into better agreement
regarding an enhanced NE flow developing next weekend with SCA winds
possible. We will continue to monitor and see how this trends.

Throughout today waves across open waters will continue to build due
to the swell from the low pressure system far off the coast. Across
the bay waves are expected to be between 1-2ft(2-3 ft across the
lower bay and 3-4 ft across the mouth of the bay). The open ocean,
waves are expected to be between 4-6 ft throughout today and into late
this week. For now, have extended SCAs across the coastal waters
through Wednesday with future extensions likely. The SCA for the
mouth of the bay has been canceled at this time. However, model
guidance has suggested an extremely marginal SCA conditions later
Today. As of now confidence is too low to warrant an extension or an
additional SCA for this zone at this time. Model and real time
trends will continue to be monitored.
-- End Changed Discussion --

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
As of 345 AM EDT Monday...

Key Messages:

- Long duration coastal flood event continues across the region
  (see section below for info on this being a record at a few
  sites).

- Water levels today are expected to be similar to Sunday. 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 continue to average +1.5 ft to +2.0 ft above
astro tide levels across the region. The high tides later today
into tonight look to reach levels similar to what occurred
Sunday aftn/evening. Again, the most widespread moderate
flooding (with local major flooding at a few places) will be
over the mid/upper Bay, including the tidal Potomac/Rappahannock
and the MD eastern shore through late this evening. These
locations still are expected to see additional 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. As such,
Coastal Flood Warnings remain in effect through Tuesday
evening.

Areas to the south across the lower Bay/tidal James and York rivers
will be more marginal, with peak water levels mostly in the high end
minor flood to locally moderate thresholds. However, given that
tidal anomalies remain fairly consistent, the high tide this
aftn/evening should be comparable to what occurred on Sunday, so
will maintain these Coastal Flood Warnings here through the late
aftn/evening timeframe. Have mentioned in the CFW the likelihood
at seeing additional flooding Tuesday (most likely minor
flooding).

Norfolk and Chesapeake remain in a Coastal Flood Advisory
through Tuesday (as opposed to a Coastal Flood Warning) given
that the Elizabeth River and Sewell`s Point should 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 this
afternoon.

Consecutive high tides reaching at least Minor Flood with this
event:

- Lewisetta (P.O.R. since 1979): 13 (with several more to
  come), previous record was 8 in Oct 2021, Oct 2019, Oct 2015.

- Cambridge (P.O.R. since 1980): 7 (with several more to come),
  previous record was 5 in Oct 2021, Oct 2019, Sep 2018, Oct
  2011.

Consecutive high tides reaching at least Moderate Flood with
this event: (this event is unlikely to break records listed).

- Lewisetta (P.O.R. since 1979): 3 (so far), ***record is 7 in
  Oct 2015***

- Cambridge (P.O.R. since 1980): 1 (so far), ***record is 4 in
  Oct 2019***

In addition, a High rip current risk is in effect today and will
likely continue through at least Tuesday.
-- End Changed Discussion --

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...Coastal Flood Warning until 2 AM EDT Wednesday for MDZ021>023.
     Coastal Flood Advisory until 4 PM EDT this afternoon 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 Tuesday night for
     VAZ075-077.
     Coastal Flood Warning until 10 PM EDT Tuesday for VAZ076-078-
     085-521-522.
     Coastal Flood Advisory until 9 PM EDT Tuesday for VAZ083-518-
     520.
     Coastal Flood Warning until 6 PM EDT this evening for VAZ084-
     086-523>525.
     Coastal Flood Warning until 10 PM EDT this evening for VAZ089-
     090-093-096.
     Coastal Flood Advisory until 6 PM EDT Tuesday for VAZ095-097.
     Coastal Flood Warning until 8 PM EDT this evening for VAZ099-
     100.
MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ650-652-
     654-656-658.
-- End Changed Discussion --

&&

$$

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