105
FXUS61 KAKQ 180709
AFDAKQ

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

.SYNOPSIS...
Low pressure located over the Carolinas will weaken today. The
low will continue to weaken and move offshore tomorrow into
Friday. A backdoor cold front potentially drops 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 300 AM EDT Wednesday...

Key Messages:

- Additional showers and thunderstorms develop today, bringing the
potential for locally heavy rainfall.

This morning, weakening low pressure is located over eastern TN.
Meanwhile, ~1022mb high pressure remains centered off the New
England coast. A stationary front is draped just south of the
forecast area. Still seeing scattered rain showers over the region,
with the highest coverage over the MD Eastern Shore and across our
northwestern counties. Some of the showers have been heavy at times,
prompting a couple of Flood Advisories just north of Richmond over
Henrico County. Expect for the best rain chances to continue to
focused over the northern half of the area through the morning
hours, though with plenty of moisture around, a light rain
shower and/or drizzle cannot be ruled out for anywhere in the
forecast area. The abundance of moisture will also allow for
patchy fog to develop over the next couple of hours, with the
best chances for fog across south central Virginia and northeast
North Carolina. Visbilities could drop to 1-2SM at times, with
locally heavier patches that could potentially drop visbilities
to less than 1SM.

Low pressure will continue to move gradually to the northwest and a
new coastal low begins to form to our northeast. It will be another
unsettled day with additional showers and thunderstorms (best
thunderstorm chances across the southern half of the area) expected
to develop during the late morning and early afternoon hours and
continue into the evening. Any showers today may produce locally
heavy rainfall, with WPC highlighting much of the area in a Day 1
Marginal ERO. It will also be another day with little in the way of
sunshine, with mostly cloudy to overcast skies expected throughout
the day. Temperatures today will range from the lower 70s across the
NW, to the lower 80s SE. Rain chances decrease overnight, with only
a slight chance for an isolated shower. Additional fog or low clouds
are also possible tonight. Lows tonight drop back into the lower 60s
NW to upper 60s SE.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
As of 300 PM EDT Tuesday...

Key Messages:

- Continued unsettled conditions Wednesday into Thursday with an
upper low lingering near the region.

- A backdoor cold front drops southeast across the local area on
Friday.

No big changes within the short term forecast. Shower chances
will continue both Wednesday and Thursday. However, Pops will
decrease during these days. An upper low gradually stalls south
of the area on Wednesday and gradually drift off to the
northeast on Thursday. With this system lingering Pops will
remain in the forecast. Wednesday the showers will be more
isolated to scattered in nature than widespread (best potential
across the western half of the area). With on shore continuing
for the week expect widespread cloud cover to continue to keep
temperatures cool (especially across the northwest) with highs
expected to range from the lower 70s NW to the lower 80s SE.
Cool and cloudy conditions continue on Thursday with decreasing
cloud cover late. Highs on Thursday will generally be in the mid
to upper 70s. A weak backdoor cold front will push SE across
the region during the day Friday, which will bring a slight
chance for an afternoon shower. Highs on Friday will range from
the upper 70s to around 80.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
As of 300 PM EDT Tuesday...

Key Messages:

- Drier, 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 Sun into early next week. Meanwhile, high pressure
remains centered in Quebec through Sat before dropping south into
New England by Mon. As the high pressure builds south, it will push
a backdoor cold front across the area Sat with cooler, drier weather
expected this weekend (especially Sun) into early next week.
However, given the low off the coast, coastal areas can expect
breezy conditions with gusts to 25-30 mph this weekend into Mon
along with greater cloud cover and humidity. Additionally, cannot
rule out a few isolated showers along the coast (15-25% PoPs).

Highs range from the mid-upper 70s to around 80F (across the
piedmont) Sat, mid 70s Sun and Mon, and mid-upper 70s Tue. Lows
range from the upper 50s (Piedmont) to mid 60s (coast) Fri night,
mid-upper 50s (Piedmont) to low-mid 60s (coast) Sat night, mid 50s
(Piedmont) to lower 60s (coast) Sun and Mon nights, and upper 50s
(Piedmont) to mid 60s (coast) Tue night.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
As of 210 AM EDT Wednesday...

Widespread IFR CIGs across the region early this morning. IFR to
patchy LIFR CIGs are expected at all sites through this morning,
before a gradual improvement to MVFR CIGs by this afternoon. In
addition to low CIGs, VSBYs are also expected to fall this
morning and generally range from 2-4SM with DZ/BR. VSBYs may
drop to less than 2SM at times across portions of south central
Virginia where more widespread fog is expected to develop.
Occasional showers continue through the night, with the highest
chances across the northern half of the area (impacting SBY).
Showers and thunderstorms develop late this morning through this
afternoon, with the highest coverage still expected to be inland
and away from the coast. Winds average 5-10 knots out of the NE
through the period. Additional IFR/MVFR CIGs (and potentially
VSBYs) are possible tonight into early Thursday morning.

Outlook: Unsettled conditions continue Thursday and Friday, but
confidence in the timing and extent of any flight restrictions
remains low. Gradually improving conditions are expected
Saturday into Sunday.

&&

.MARINE...
As of 400 PM EDT Tuesday...

Key Messages:

- Small Craft Advisories remain in effect for the Chesapeake Bay
  and lower James River area this evening.

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

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

Latest sfc analysis shows an area of 1024+ mb high pressure to
centered to the north over New England. To the SW, the weakening
remnants of PTC 8 continues to meander over the Carolinas. The
tight pressure gradient between these features has allowed for
elevated winds and waves to continue this afternoon. Latest obs
reflect easterly winds of 15-20kt with a few gusts into the
20-25 kt range, mainly in the lower bay and lower James River.
Seas are slowly subsiding as well, but are still up around
6-7ft, with waves 3-5ft, highest in the lower bay.

The sfc low will continue to meander to our SW through tonight,
allowing the pressure gradient to slowly relax and winds to
gradually improve from S to N through the night. Winds should
decrease further late this evening and overnight, as a weak
area of secondary low pressure passes over the coast overnight.
Winds diminish to 10-15kt overnight, which will continue
through Wednesday. Seas should also improve through Wed, but
the onshore wind and E-NE swell (8-10 second) will make this
improvement gradual. SCA has been allowed to drop over the
sound and upper rivers, and will extend into late this evening
over the Bay and lower James River. Seas will linger in the 4-6
ft range over southern waters through tonight then slowly
subside from south to north through the day tomorrow. We`ve made
only minor adjustments to SCAs there accordingly.

The coastal low then exits to the NE as high pressure builds in
from the NW. Winds veer around to the N/NW for Thu-Fri at
~10kt, and it appears that we should get a couple of days of
sub- SCA conditions in to the end work week. Seas will be
3-4ft, waves 1-2ft. However, conditions become unsettled once
again with another protracted round of SCAs appear increasingly
likely over the weekend due to the re-tightening of the sfc
pressure gradient between high pressure pushing in from the NNE
and low pressure retrograding south just offshore. This will
result in re-building NNE winds over the weekend, with seas
quickly building to 5-8 ft, driven largely by renewed E-NE
swell.

&&

.TIDES/COASTAL FLOODING...
As of 400 PM EDT Tuesday...

Astronomical tides will continue to increase through this
evening 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 tonight. Have issued a round of CF
Advisories for the upcoming high tide cycle tonight for much of
the bay, VA eastern shore, and adjacent tributaries. Tide
levels have so far remained below flood thresholds on the
eastern shore, but with the upcoming astronomically higher tide
cycle and given the slight upward trend, have issued a CF
statement over the bay side of the lower MD eastern shore.

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. So far,
moderate flooding is not expected through Friday. 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 4 AM EDT early this morning for
     ANZ632-634.
     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
SHORT TERM...AJB/HET
LONG TERM...RMM
AVIATION...AJB
MARINE...AM/MAM
TIDES/COASTAL FLOODING...