Area Forecast Discussion
Issued by NWS Wakefield, VA

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025
FXUS61 KAKQ 181436
AFDAKQ

AREA FORECAST DISCUSSION
National Weather Service Wakefield VA
1036 AM EDT Wed Sep 18 2024

.SYNOPSIS...
Low pressure located over the Carolinas will weaken today, and
will move offshore tomorrow into Friday. A backdoor cold front
potentially drops back south across the region Friday night
through Saturday. High pressure builds north of the area this
weekend into early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM EDT Wednesday...

Key Messages:

- Additional showers today, with a few storms possible over
  southern sections. Any showers bringing the potential for
  locally heavy rainfall.

Latest analysis reveals the remnant low of PTC8 weakening over
the west-central portion of SC. To the east, weak secondary low
pressure continues to develop offshore. Meanwhile, ~1022mb high
pressure remains centered off the New England coast.

Only minor changes to the going forecast for the afternoon. Low
pressure will continue to weaken as it moves gradually to the
northwest and the coastal low takes shape offshore. Remaining
unsettled day, with scattered showers, and potentially a few
thunderstorms across the southern half of the area where some
clearing will ensue through mid-afternoon. Given the low to the
south, deep layer moisture and some weak forcing for ascent
along the occluded front lifting north, a few showers could
produce locally heavy rainfall. WPC continues to highlight much
of the central and eastern VA area in a Day 1 Marginal ERO.
Mostly cloudy to overcast skies throughout the day, though
thinning clouds could provide for some opaque sunshine across
southern VA and NE NC (mainly US-58 southward). Temperatures
today will range from the lower 70s across the NW, to the lower
80s SE.

Rain chances quickly decrease with loss of heating and taper
down further overnight, with only a slight chance for an
isolated shower. Low-level moisture along the front likely
portends another night of fog and/or low clouds late tonight and
overnight. Lows tonight drop back into the lower 60s NW to
upper 60s SE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
As of 330 AM EDT Wednesday...

Key Messages:

- Decreasing rain chances Thursday and Friday

As the coastal low lifts further to the NE on Thursday, expect a
drier day compared to today with even some partial clearing
(especially west) late in the day. Still, isolated to scattered
afternoon showers or storms will be possible, with the best chances
across far southern Virginia into northeast North Carolina (30-40%
PoPs). High temperatures on Thursday will generally be in the upper
70s area-wide and low temperatures will range from the upper 50s to
lower 60s. Sunshine returns Friday with temperatures warming into
the upper 70s to around 80. A backdoor cold front pushes south into
the area later Friday into Friday night, bringing a slight chance
for an afternoon shower (mainly across the MD Eastern Shore). Low
temperatures Friday night range from the upper 50s to the lower 60s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 330 AM EDT Wednesday...

Key Messages:

- Drier and cooler weather arrives this weekend into early next
week.

Aloft, a tall upper level ridge builds well into Canada and
Greenland with an upper level trough along the East Coast this
weekend into early next week. At the surface, low pressure lingers
off the Mid Atlantic coastline through the weekend, gradually
shifting south Sunday into early next week. Meanwhile, high pressure
remains centered in Quebec through Saturday before dropping south
into New England by Monday. Cooler weather is expected by Sunday and
especially Monday, with highs only in the low to mid 70s. Overnight
lows will generally be in the 50s away from the coast. Given the low
off the coast, coastal areas can expect breezy conditions with gusts
to 25-30 mph this weekend into Monday along with greater cloud cover
and humidity. Additionally, cannot rule out a few isolated showers
along the coast (15-25% PoPs).

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
As of 645 AM EDT Wednesday...

Widespread IFR to LIFR CIGs continue across the region this
morning. IFR CIGs likely try to hang on during much of the
daytime hours, with ECG having the best potential to see a
brief window of MVFR CIGs this afternoon. Additional showers
develop this morning through this afternoon, leading to the
potential for MVFR to IFR VSBY restrictions under any heavier
showers. Winds average 5-10 knots out of the NE through the
period. IFR to LIFR CIGs redevelop tonight and are expected for
the remainder of the forecast period.

Outlook: Sub-VFR CIGs likely stick around into early Thursday
afternoon, before a potential improvement late.  Gradually
improving conditions are then expected on Friday and Saturday.

&&

.MARINE...
As of 345 AM EDT Wednesday...

Key Messages:

- Small Craft Advisories linger into the evening for the
  coastal waters due to elevated seas.

- Another round of Small Craft Advisory conditions appears
  increasingly likely this weekend into early next week.

A weak area of secondary low pressure is forming along the SE coast
this morning while high pressure remains anchored to the N. Winds
remain onshore, but a relaxing pressure gradient has allowed for
diminishing winds overnight. Latest obs indicate winds generally at
10-15kt. Seas are slow to diminish given onshore flow. Early morning
buoy obs show 5-6ft seas. Remaining SCAs in the bay will be allowed
to expire early this morning. Low pressure will shift the NE through
this evening as high pressure wedges in behind it. Winds will shift
to the NE this morning, remaining breezy over the upper bay and
northern coastal waters at ~15kt. Elsewhere, winds will be 10-15kt
today. Seas S of Cape Charles Light should drop back to 3-4ft this
afternoon, allowing the SCA there to end. Northern waters will be
slower to diminish, so SCAs will likely last into late tonight.
Winds shift to the N at 5-10kt across all waters overnight. These
conditions continue through Thurs evening as low pressure lingers
offshore Thurs and high pressure remains overhead. SCAs may have to
be extended for the northernmost zones for 5ft seas. However, it
looks marginal so far with 5ft seas only hanging on out near 20nm.

The offshore low looks to stick around through at least half the
weekend with high pressure wedged in behind it. Northerly winds
continue Fri, becoming at little breezier at 10-15kt by the
afternoon. SCAs are likely to return for at least northern coastal
waters Fri afternoon as seas build back toward 5-6ft. Low pressure
potentially retrogrades slightly Sat, leading to a tighter pressure
gradient and higher winds. NE winds increase to 15-25kt Sat (highest
over northern waters). Hazardous marine conditions likely continue
through Sun.

&&

.TIDES/COASTAL FLOODING...
As of 350 AM EDT Wednesday...

Astronomical tides will continue to increase with the approach
of the next full moon. Higher astro tides along with prolonged
onshore flow will lead to 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 extended CF Advisories
through the morning high tide cycle tonight for much of the bay,
and adjacent tributaries. Have also extended the coastal flood
statement for the Eastern Shore given levels hitting minor flood
thresholds at Bishop`s Head, but remaining under flood
thresholds other nearby sites.

Additional advisories/extension of Advisories will likely be
needed through the end of the week and into the weekend due to
extended periods of onshore flow and high astro tides. Low end
moderate flooding is possible at particularly vulnerable spots
(Bishop`s Head, Oyster), but otherwise staying within minor
flood thresholds so far. However, a building flood tide
Saturday into Saturday night does bring the potential for tide
levels reaching moderate Coastal Flood Thresholds (best chances
northern coastal zones and lower bay) for tide cycles over the
upcoming weekend.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...Coastal Flood Advisory until 5 PM EDT this afternoon for
     VAZ075-077.
     Coastal Flood Advisory until 2 PM EDT this afternoon for
     VAZ076-078-085-522.
     Coastal Flood Advisory until 11 AM EDT this morning for VAZ084-
     086-089-090-093-095>100-523>525.
MARINE...Small Craft Advisory until 6 AM EDT Thursday for ANZ650.
     Small Craft Advisory until 1 AM EDT Thursday for ANZ652-654.
     Small Craft Advisory until 1 PM EDT this afternoon for ANZ656-
     658.

&&

$$

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