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000
FXUS61 KAKQ 211156
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
756 AM EDT Mon Aug 21 2017

.SYNOPSIS...
High pressure becomes centered off the Mid Atlantic coast
through Tuesday. A cold front crosses the area late Wednesday,
with strong high pressure building north of the area from Thursday
into the upcoming weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
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Latest analysis indicating a broad area of ~1022 mb sfc high
pressure centered over the local area. Main concern early this
morning continues to be areas of fog, locally dense over
portions of central/southern VA. Have issued another SPS through
9am to account for this, but overall conditions are now
improving.

Otherwise for today, expect partly cloudy/variably cloudy skies
N and partly-mostly sunny south with decent eclipse viewing
expected for the most part this aftn. With some weak upper
level shortwave energy currently over IN/OH moving east through
the day, should see enough of a trigger for sct convection to
develop across the mts then drift e-se across the northern most
zones of the fa by around 18Z. Will carry chc PoPs to 30-40%
mainly north of RIC, with 20% into metro RIC and dry across the
south. Highs upr 80s- lwr 90s except mid 80s at the beaches.
Hourly temperature forecast has temperatures falling a few
degrees during the eclipse (18/19Z), then rising again through
21Z. Becoming mostly clear this evening/except partly cloudy NE
where a 20-30% PoP will be maintained. Warm/humid with lows
mainly 70-75 F tonight.
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&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
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Hot/mainly dry Tues ahead of the approaching cold front. 85-90 F
along the coast, 90-95 F west of the bay. Dry most of Tues
night except increasing moisture could lead to a few showers by
daybreak across nrn most zones. Warm with most areas having
lows only in the mid 70s.

Frontal boundary a bit slower to traverse the fa Wed. This combined
with a weak wave progged to move east along it will spread widespread
moisture and support likely pops in the afternoon, but probably
not much in the morning (especially over the SE). Another round
of mdt to hvy downpours possible ahead and along the fropa.
Highs mid 80s NW to around 90 F south.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A cold front gradually drops through the area Wednesday
night into Thursday morning. Modest ascent accompanies the front
within the RRQ of a ~110kt jet over New England along with pw
values to around 2.0" (around +1 st dev). The highest PoPs by
Wed evening look to focus across srn VA/NE NC where 70% will be
maintained, tapered to ~30% across the NW where drier air arrive
first. PoPs across SE portions gradually diminish to 20-40% by
Thursday aftn. Thunder will be maintained into Wednesday
evening, with showers thereafter as stable NE flow prevails in
the wake of the front. Drier air gradually filters in from the
NW late Wednesday night into Thursday with partial clearing
across the nrn tier counties. Lows Wednesday night range from
the mid 60s NW to the low 70s SE, followed by highs Thursday in
the upper 70s to low 80s. ~1025mb (+1 st dev) high pressure
builds from the Great Lakes across the Saint Lawrence Valley and
into New England Thursday nigh through Sunday. This will result
in persistent onshore flow, which combined with a drier airmass
will result in a series of pleasant days with highs in the
upper 70s at the coast to low 80s inland, with lows in the upper
50s to low 60s inland, and mid/upper 60s along the coastlines.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
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Patchy fog/low stratus across the region early this morning,
mainly affecting RIC through 13-14Z. After the fog/low cloud
burns off, VFR conditions will prevail. Isolated tstms in the
aftn/evening possible at RIC/SBY but still mainly dry. Continued
mainly dry and probably will see a little less in the way of
fog/low cloud Tue morning as southerly flow becomes a little
stronger. The next cold front approaches the region Wed, and
flight restrictions will be possible Wed, mainly in the aftn and
through Wed night in showers/tstms. Some showers may linger
across SE terminals into Thu morning, but otherwise improving
conditions except with a breezy NE flow near the coast Thu/Fri.
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&&

.MARINE...
Early this morning, sfc high pressure was cntrd over the area.
The high will move off the coast and out to sea today through
Tue, and a cold front will approach the waters Tue night into
Wed morning. The front will then cross the area Wed/Wed night
and will push well SE of the area during Thu, with high
pressure building back into the region for the remainder of the
forecast period. Expect SE or S winds around 10 kt or less
during today, as high pressure moves offshore. Winds increase
and become SSW ahead of the approaching cold front Tue through
Tue night. Winds speeds may approach 15 to 20 kt over the Ches
bay and ocean with seas building to 3 to 4 ft, potentially up to
5 ft north/20nm out, and waves building to 2 to 3 ft. A Small
Craft Advisory may be needed for the Chesapeake Bay and nrn two
coastal zns Tue night. Winds shift to the N/NE behind the front
late Wed through Thu around 10 to 15 kt.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...AJZ
AVIATION...LKB
MARINE...TMG