Area Forecast Discussion
Issued by NWS Wakefield, VA

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FXUS61 KAKQ 230003
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
803 PM EDT Sat Sep 22 2018

.SYNOPSIS...
A weakening cold front will pass through the mid Atlantic
region this evening, and then will stall just south of the area by
Sunday. Strong high pressure will remain anchored over New England
through Monday.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 400 PM EDT Saturday...

* An additional tornado touchdown has been confirmed invof
  Windsor Farms, bringing the total to Monday (9/17) to 10
  confirmed tornadoes from 6 different storm cells. See
  https:/weather.gov/akq/Sep172018_Tornadoes for details.

The current surface analysis places a cold front from
the mountains of SW VA through central VA and into the Ern Shore,
with a pre-frontal wind shift reaching the Albemarle Sound. 1028mb
high pressure is centered over the Great Lakes, and weaker high
pressure is centered off the Southeast coast. Enhanced low-level
convergence is resulting in some showers developing over the VA Ern
Shore, and additional activity is expected to develop over the SW
Piedmont counties late this aftn and early evening. Partly sunny to
mostly cloudy this aftn, and still warm and humid ranging from the
upper 70s/low 80s far NW, to the mid/upper 80s SE, with dewpoints in
the mid 60s to low 70s across the area.

The front is expected to gradually drop through the region tonight,
with cooler air eventually arriving from the N through the evening
and overnight hours, mainly from the Piedmont the MD Ern Shore. A
shortwave trough, and jet max aloft will interact with the front by
tonight with showers expanding in coverage from the Piedmont into
central VA, with more isolated to scattered showers farther E and
SE. Locally heavy rain and embedded thunder are possible given that
the forcing aloft will still have a moisture rich airmass to
interact with. Lows tonight range from the low 60s N/NW, to the
mid/upper 60s farther SE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
As of 400 PM EDT Saturday...

Strong high pressure builds into New England Sunday,
and the front stalls immediately S of the area, with a CAD wedge
developing over nrn and wrn portions of the area. The disturbance
aloft will pass through the area through the morning and midday
hours and move off the NE by aftn. PoPs will be highest from morning
through midday, and then diminishing by aftn. Cloudy NW, with even
more of a stratiform rain developing, while more isolated to
scattered coverage farther SE, with a slight chc of thunder under a
variably cloudy sky. Highs Sunday range from the low 60s NW in the
in situ wedge, to the low 80s far SE.

By Sunday night and Monday, the frontal boundary remains stalled S
of the local area. Meanwhile, 1035+mb high pressure remains over New
England to Atlantic Canada. A weak CAD setup will linger Monday and
depending on cloud cover high temperatures could be similar to
Sunday. Forecast highs range from the mid/upper 60s NW to around 80F
SE. PoPs will average 30-40% SE to ~60% N Sunday night into Monday.

The front begins a slow drift to the N Monday night. Plenty of low-
level moisture in combination with the front should result in
widespread low clouds. PoPs remain ~60% far N, and drop to 20-30% S
and SE. Forecast lows range from the mid 60s NW (similar to the
previous days highs) to the low 70s SE. Clouds slowly lift Tuesday,
with variably to partly cloudy conditions by aftn. Forecast highs
range from the upper 70s N/NW to the mid 80s SE along with a chc of
showers and slight chc of tstms.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 400 PM EDT Saturday...

Unsettled conditions through much of the medium range with multiple
low pressure systems impacting the region. We start the period
mainly dry Tuesday night with the area in the warm sector ahead of
the next front. This cold front approaches the region during the day
on Wednesday before slowly crossing the region late Wednesday night
into Thursday morning. Showers and thunderstorms will increase in
coverage from northwest to southeast Wednesday afternoon and become
more numerous by Wednesday evening. Both the GFS and ECMWF have this
front lingering across southeastern portions of the area during the
day Thursday into Friday allowing for the continued threat of
showers and thunderstorms. A secondary cold front makes its way
through the area on Friday with high pressure building back north of
the area Friday night into Saturday. It will be feeling more like
mid-August rather than Fall on Wednesday with highs ranging from the
mid to upper 80s and dewpoints in the lower 70s. Highs on Thursday
could see a big range depending on the frontal timing/position, will
go similar to the previous forecast with highs ranging from the mid
70s across the northwest to the mid 80s across the southeast. Highs
in the upper 70s to lower 80s Friday and mid 70s to lower 80s
Saturday. Lows in the 60s to near 70 Wednesday/Thursday night, upper
50s to upper 60s Friday night.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
As of 800 PM EDT Saturday...

A cold front is oriented along and just south of the VA/NC
border at 00z, oriented just n of KECG. Mainly VFR conditions
with some sct-bkn MVFR CIGs along the frontal boundary. The
wind has shifted to NE at most sites, with the exception of ECG
where the wind remains SW. Sct showers/tstms are possible along
the front this evening, but otherwise expect little if any pcpn
at terminals through 06z. Some sct stratiform showers possible
at RIC/SBY/PHF overnight into the early morning hours Sunday,
with CIGs trending down towards MVFR.

Front settles over nrn NC Sunday, with some redeveloping
showers possible along the boundary. Stratiform rain is expected
over N/NW portions of the area Sunday, with sct showers and
perhaps a tstm farther SE (KECG). The wind will become NE at
all sites, with gusts up to 20kt possible along the coast. As
the cool air wedge develops inland, expect low end MVFR to IFR
CIGs inland by late aftn Sunday into Sunday night, but still
only average confidence of exact timing attm. Possible coastal
sections around ORF could remain stuck in MVFR Sunday afternoon,
w/lower CIGs/additional stratiform rain/drizzle lingering
inland. For now, have stayed with more optimistic with low-end
VFR prevailing at ORF by aftn.

Outlook: The front lifts N of the area Late Tue and Wednesday,
with another cold front approaching from the NW Thursday.

&&

.MARINE...
As of 420 PM EDT Saturday...

Late this aftn, a frontal boundary was sinking south thru the
waters, and was near the VA/NC border. NNE winds were mainly
5-15 kt behind the front, and SE 5-10 kt south of the boundary.
The frontal boundary will drop south of the NE NC waters Sun
morning. Then, NE and E winds will increase over the entire
waters Sun aftn thru Mon, as strong high pressure builds acrs SE
Canada and nrn New England. Have adjusted start times of SCA`s
to later Sun morning or Sun aftn, and continued them thru at
least Mon for now. Did not issue SCA yet for NC waters, because
conditions may not start to occur until Mon. Expect NE or E
winds 15-25 kt, with possible gusts up to 30 kt in the nrn
waters. Expect seas to build to 5-8 feet over the ocean, with
3-5 foot waves on the bay. The SCAs will likely have to be
extended thru Tue, esply for the coastal zns, as E then SE winds
will keep seas elevated.

&&

.TIDES/COASTAL FLOODING...
As of 420 PM EDT Saturday...

No coastal flooding is expected through tonight, as tidal
anomalies should gradually fall as the wind shifts to the N
behind a cold front. Onshore flow develops Sun into Mon, as
strong high pressure builds over New England. Tidal anomalies
will once again increase for much of the area, with additional
areas of coastal flooding likely w/ High tide cycles Mon night
and Tue.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 1 PM Sunday to 5 PM EDT Monday for
     ANZ634>638-656.
     Small Craft Advisory from 10 AM Sunday to 5 PM EDT Monday for
     ANZ630>632-650-652-654.

&&

$$
SYNOPSIS...AJB/AJZ
NEAR TERM...AJZ
SHORT TERM...AJZ/ALB
LONG TERM...ALB
AVIATION...AJZ/MAM
MARINE...TMG
TIDES/COASTAL FLOODING...


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