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750
FXUS61 KAKQ 200741
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
341 AM EDT Fri Sep 20 2024

.SYNOPSIS...
High pressure will remain north of the region while low pressure
remains well offshore. A backdoor cold front potentially drops
back south across the region Saturday. High pressure builds north
of the area this weekend into early next week leading to generally
dry conditions. A cold front potentially approaches by the middle
to later portions of next week.

&&

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

Key Messages:

- Patchy fog possible this morning.

-Pleasant today with mostly sunny skies and highs in the upper
 70s-low 80s.

An area of sfc low pressure, along with an UL low, remain situated
off the Northeast coast this morning with high pressure
(centered to the N) in place over the local area. Skies have
cleared out over much of the area, but some mid level stratus is
hanging on over the SW corner of the FA. Calm to light winds
combined with the moisture from the rain over the last couple of
days has allowed for fog formation where the skies have
cleared. While this has mostly been patchy so far, a few of the
latest obs do indicate denser spots in the NW and near the VA/NC
border. Fog should clear up within an hour or two of sunrise.
Lows this morning will be in the low 60s. Expecting a pleasant
day today with highs in the in the low 80s for much of the area.
Continued onshore flow will keep temps in the mid-upper 70s
closer to the coast. Skies will be mostly sunny. Lows tonight
will be on either side of 60. With mostly clear skies and calm
to light winds, could see another round of morning fog Sat.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
As of 340 AM EDT Friday...

Key Messages:

- Showers or isolated storms possible Saturday evening into Saturday
night.

- Cooler and mainly dry Sunday.

Pleasant weather continues into Sat with high pressure still in
place over the NE CONUS and low pressure offshore slowly drifting S.
Aloft, NW flow will remain in place over the local area with a broad
ridge to the W and low pressure offshore. Highs will be around 80.
CLoud cover will gradually increase from NW to SE as a shortwave
approaches, traveling down the ridge. To add to that, a backdoor
front will drop S into the area Sat night. Day-time hours look to
remain mostly dry Sat, though could see a showers enter to the NW
counties later in the afternoon. The scattered showers (and a
few rumbles of thunder) then cross through the area Sat evening/night
with highest PoPs (45-55%) staying N of I-64. Mostly cloudy
skies will hang on across the NE half of the area for much of
Sun. Not expecting much in the way of precip, but cannot rule
out a stray shower near the coast with the UL trough in the
vicinity. Temps will range from the low 70s in the NE on the
Eastern Shore to around 80 in the SW. Lows Sun night will be in
the upper 50s to low 60s.
-- End Changed Discussion --

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
-- Changed Discussion --
As of 340 AM EDT Friday...

Key Messages:

- Dry, overall pleasant weather Monday.

- Gradually warming temps expected by the midweek, with low-end
precipitation chances potentially returning.

Sfc high pressure centered well to the N of the area will continue
to wedge itself down the east coast Mon as low pressure well
offshore drifts further S. Thicknesses will increase as a ridge
aloft slides east toward the coast through mid-week. Monday will be
pleasant with highs in the mid 70s and partly sunny skies. Gusty
onshore winds will keep areas immediately along the coast a couple
of degrees cooler. Lows Mon night will be around 60. Precip chances
potentially inch back up by Tuesday and especially Wednesday as a
quick-moving shortwave ejects out of the Midwest, likely interacting
with the next deep-layer trough coming out of the nrn US and Canada.
00z deterministic guidance shows several waves of precip
associated with various smaller-scale disturbances. Timing these
disturbances is difficult at this lead time and given
associated spread across the ensemble guidance, will remain near
or slightly above NBM PoPs during this period. This yields chc
PoPs Tuesday aftn across the W, with 30-40% PoPs for most of the
area Wednesday into Thurs with the parent cold front. Sky cover
averages partly-mostly cloudy. Temps Tues-Thurs will be similar
each day with mid 70s in the NW to upper 70s-around 80 in the
SE. Forecast overnight lows are around 60 Monday night, and
lower 60s Tuesday/Wednesday night.
-- End Changed Discussion --

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
As of 200 AM EDT Friday...

VFR prevails at the start of the 06z TAF period. Have seen some
fog forming tonight across the region, but it has generally
stayed away from the terminals so far. Do expect MVFR vsbys to
impact some, if not all, the terminals later this morning. Fog
will clear out an hour or two after sunrise, then VFR is
expected the rest of the 06z period. Winds will be light
overnight, then NE winds become gusty at the coast during the
day (gusts 15-20kt).

Outlook: Primarily VFR conditions expected through Sat
afternoon. Scattered showers Sat evening may bring brief flight
restrictions.

&&

.MARINE...
As of 955 PM EDT Thursday...

Key Messages:

- Small Craft Advisories have been issued for the coastal waters
  north of Parramore Island.

- Additional Small Craft Advisories possible as early as
  tomorrow afternoon for seas, with SCAs likely this weekend
  into early next week.

- Stronger NE winds return on Sunday, with persistent long
  period swells keeping seas elevated this weekend into the
  middle of next week.

Went ahead and issued SCAs for the coastal waters N of Parramore
Island as 5ft seas should return by late morning-midday Friday.
No other changes to the going forecast.

Previous Discussion as of 320 PM...

Latest obs and buoy reports reflecting N/NE winds 10-15 kt over the
waters this afternoon. Deepening ~1004 mb sfc low pressure continues
meander just south of the southern New England coast, with the
system stalled due to a blocking area of high pressure centered off
the coast of Nova Scotia. Meanwhile, weak 1015+mb sfc high pressure
builds NW of the waters. Resultant NNE winds continue this evening,
backing to the NW as the surface high starts to build overhead.
Buoy obs reflect seas subsiding largely as expected this afternoon.
Seas were 3-4ft S of Cape Charles Light and ~4-5ft to the N. SCAs
were lowered earlier today south of Parramore Island, and will be
allowed to expire with the issuance of the afternoon package.

Winds slowly diminish and back to the NW as the pressure gradient
relaxes with high pressure building across the lower mid-Atlantic.
will allow for further improvement in marine conditions. Expect seas
to gradually improve as well with winds turning offshore and
diminishing. Seas generally 3-4 ft, waves 1-2 ft.

Previously referenced blocked low pressure south of Nantucket
remains more or less in place on Fri. While N/NE winds will be sub-
SCA at 10-15kt Fri-Sat, E-NE wind waves (8-10 second swell)
from the offshore low arrives Fri morning into the afternoon,
leading to seas increasing once again. Northern coastal waters
will see 5-6ft seas by midday Friday, and by late Friday
evening into Sat morning across southern coastal waters and the
mouth of Chesapeake Bay. The pressure gradient over the waters
also starts to tighten up again late Saturday and Sunday as the
low dives SE. This should increase NE winds during this period,
especially over coastal waters. The bay/rivers will likely need
SCAs for winds ~20kt as early as late Sat night, but more
likely on Sunday. Winds over coastal waters look to be 20-25kt.
Building swell combined with elevated winds should allow seas to
build to 6-8ft in the N and 5- 7ft S. While winds look to
improve early next week, but energetic long period (E-NE, ~10
second) swells from the lingering low well offshore of New
England will keep seas in 4-6 ft range over the coastal waters
through at least the middle of next week.

&&

.TIDES/COASTAL FLOODING...
As of 910 PM EDT Thursday...

Tide forecast is tracking well this evening. Went ahead and
added areas around Tappahannock/West Point to the advisory based
on observations/model forecasts. Otherwise, no major changes to
the going forecast.

Previous Discussion as of 320 PM EDT...

Astronomical tides continue to increase with the approach of the
coming full moon (Harvest moon) cycle. Astronomically higher astro
tides, along with prolonged onshore flow will continue to produce
tidal anomalies of 1-1.5 ft, resulting in nuisance to low-end minor
tidal flooding across much of the area along the bay and tidal
rivers through the end of the week. Have opted to extend the Coastal
Flood Advisories given similar water levels near minor flood
thresholds through Friday evening`s high tide cycle. While winds
briefly diminish and turn offshore, the ebb tide will be short-
lived, as winds turn back onshore over the weekend.

Additional extension of advisories or perhaps Coastal Flood Warnings
are likely to be needed over the weekend. Will hold coastal flood
headlines at Friday night for now. Winds turning back onshore and
gradually increasing Sat night and Sunday should bring building
flood tide Saturday into Saturday night. With anomalies
increasing once again, the potential for tide levels reaching
moderate Coastal Flood Thresholds (best chances northern coastal
zones and lower bay) does increase for tide cycles over the
upcoming weekend. Coastal Flood Watches may be issued in
upcoming forecast cycles for the weekend.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...Coastal Flood Advisory until 10 AM EDT Saturday for MDZ021>023.
     Coastal Flood Watch from Saturday afternoon through Saturday
     evening for MDZ021>023.
     Coastal Flood Advisory until 4 PM EDT Saturday for MDZ024-025.
NC...Coastal Flood Advisory until 6 PM EDT Saturday for NCZ102.
VA...Coastal Flood Advisory until 6 PM EDT Saturday for VAZ083-084-
     086-095>100-518-520-523>525.
     Coastal Flood Advisory until 8 AM EDT Saturday for VAZ075-077.
     Coastal Flood Watch from Saturday afternoon through late
     Saturday night for VAZ075-077.
     Coastal Flood Advisory until 6 AM EDT Saturday for VAZ076-078-
     085-521-522.
     Coastal Flood Watch from Saturday morning through Saturday
     evening for VAZ076-078-085-521-522.
     Coastal Flood Advisory from noon today to 6 PM EDT Saturday
     for VAZ089-090-093.
MARINE...Small Craft Advisory from 10 AM this morning to 6 AM EDT
     Sunday for ANZ650-652.
-- End Changed Discussion --

&&

$$

SYNOPSIS...AJB/SW
NEAR TERM...AM
SHORT TERM...AM
LONG TERM...AM/SW
AVIATION...AM
MARINE...ERI/MAM
TIDES/COASTAL FLOODING...