-- Discussion containing changed information from previous version are highlighted. --
810
FXUS61 KAKQ 191925
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
325 PM EDT Thu Apr 19 2018

.SYNOPSIS...
A cold front will push off the coast this afternoon. Dry
weather with below normal temperatures will prevail Friday
through the weekend.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
As of 1025 AM EDT Thursday...

Late this morning, sfc low pressure was just off the New Jersey
coast. A cold front extended fm the low SW acrs SE VA and NE NC.
A few light showers behind the front were moving thru the VA nrn
neck, middle peninsula, and into the Lower MD and VA ern shore.
The cold front will push off the coast this aftn, and despite
meager moisture fields, there is sufficient forcing associated
with a potent mid-level shortwave trough for iso-sct shras over
the NE counties thru this aftn. Otherwise, decreasing clouds
this aftn with dewpoints dropping quickly behind the front. The
low RH and WNW winds gusting up to 25-35 mph will lead to
increased fire danger this aftn (see fire wx section below for
more info). High temps will range fm the upper 50s to lower 60s
far N, to the lower 70s extrm SE VA and NE NC.

Winds slowly decrease tonight, under a mostly clear sky. Should
be too dry for frost, but temps are expected to bottom out
near 32F over portions of the Piedmont where a Freeze Watch has
been issued. Low temps in the mid/upr 30s elsewhere.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
As of 400 AM EDT Thursday...

Dry/cool wx Fri as lo pres is slow to exit New England and hi
pres only gradually builds into the local area from the NW.
Still hanging on to a gusty NW wind near the coast. Mostly
sunny w/ highs mainly 55-60F.

Dry/cool wx continues Fri night-Sat as sfc hi pres arrives from
the NW. Winds to decouple/become light most places Thu night
resulting in another night w/ lows in the mid 30s inland
to around 40F near coast in ern/SE VA-NE NC. Mostly sunny Sat
w/ N winds aob 10 mph and highs from the u50s E to the l-m60s
along-W of I 95.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
As of 420 PM EDT Wednesday...

Below average temperatures expected through the bulk of the extended
period as surface high pressure slowly moves from the wrn Great
Lakes to New England from Sunday through Tuesday. At the same time,
a low pressure system slowly tracks from the srn Plains to the
southeastern US. Rain chances return early next week as that same
area of low pressure tracks northeastward up the Atlantic coast.
Some track/timing differences exist between the 18/12z suite of
guidance. GFS brings in the rain late in the day on Monday while the
ECMWF holds it off until Tuesday PM and has much less QPF than the
GFS. CMC keeps all of the precipitation south of the CWA. Given the
uncertainty, kept PoPs around 40% for the bulk of the CWA from Tue-
Wed.

Highs in the mid-upper 60s Sun-Wed from Central VA to NE NC.
Slightly cooler on the Ern Shore with low 60s Sun-Tue warming to mid
60s by Wednesday. Lows mainly in the 40s throughout the CWA on
Mon/Tue rising to around 50 Wed AM with the clouds/possible
rain.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
As of 320 PM EDT Thursday...

Mainly VFR through the 18Z TAF period. Cold front was pushing
just off the NE NC coast by 300 pm this aftn. SCT to BKN SC and
AC were along the front, and behind the front with the cooler
air aloft. WNW winds were 10-20 kt with gusts up to 30-35 kt
this aftn. SCT to BKN SC and AC will move off the coast or
dissipate early this evening, leaving SKC at the TAF sites for
late this evening into Fri aftn. NNW winds will diminish during
this evening/early tonight, as high pressure starts to build in
fm the NNW.

Outlook: VFR conditions will then continue late Fri aftn through
Sun, as high pressure builds down over the region. NNW winds
arnd 10 kt or less (10-15 kt at the coast) on Fri, then N to NE
10 kt or less on Sat.

&&

.MARINE...
As of 300 PM EDT Thursday...

Latest weather analysais reveals low pressure now oriented just
offshore of the Outer Banks at 18z. The attendant surface cold
front now offshore, extending south into the coastal Carolinas.
Obs and buoy reports indicating post-frontal surge of NNW winds
just pushing across northern portions of the waters this
afternoon. Convective gusts to ~40 kt possible with initial
surge, quickly leveling off to WNW 15-25kt in post-frontal CAA.
Winds then become NW 15-25kt tonight, with gusts up to 30kt for
the Bay/ocean. Seas build to 4-6ft later this aftn into
tonight, while waves in the Bay remain ~2ft this afternoon,
increasing to 3-4ft tonight.

Current SCA flags will remain as is, but there will be a few
hours of sub- SCA conditions across the southern waters this
afternoon before CAA makes it farther south. High pressure
builds in from the NW Friday into Friday night. A secondary
surge is expected Friday night, but this surge should generally
be sub- SCA. High pressure will build over the region Saturday
and Sunday resulting in benign marine conditions. High pressure
pushes off the Srn New England coast early next week as low
pressure pushes off the Southeast coast. This will result in
increasing onshore flow.

&&

.FIRE WEATHER...
As of 1025 AM EDT Thursday...

WNW winds will gust to 25-35 mph this aftn into early this
evening behind a cold front. This pattern looks favorable given
the time of year, due to typical lag in the arrival of cold air
to the sfc as the downslope offsets the drop in 850 mb
temperatures for increased fire concerns. After coordination
with the VA fire service, have an Increased Fire Danger
Statement (SPS) for this aftn/early this evening over central
and eastern VA, as WNW winds become gusty to 25-35 mph and most
RH values fall to 25-30%. Also, have an SPS for Increased Fire
Danger for all of NE NC except the NC Outer Banks, and for the
VA ern shore and VA Beach.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...Freeze Watch from 2 AM EDT Friday through Friday morning for
     VAZ048-060>062-064-067>069-509>511.
MARINE...Small Craft Advisory until 10 AM EDT Friday for ANZ630>634-650-
     652-654-656-658.
     Small Craft Advisory until 7 AM EDT Friday for ANZ635>638.

&&

$$
SYNOPSIS...MAS
NEAR TERM...MAS
SHORT TERM...ALB/MAS
LONG TERM...ERI
AVIATION...TMG
MARINE...MAM
FIRE WEATHER...AKQ