Area Forecast Discussion
Issued by NWS Wakefield, VA
FXUS61 KAKQ 292058
Area Forecast Discussion
National Weather Service Wakefield VA
358 PM EST Tue Nov 29 2016
A complex weather system over the Midwest and Northeast States will
affect the region through Wednesday night. A cold front approaches
from the west and crosses the Mid Atlantic States Wednesday night.
High pressure slowly builds into the area Thursday through Sunday.
.NEAR TERM /THROUGH WEDNESDAY/...
A weak short wave was producing a band of showers from south
central Virginia to the Lower Maryland Eastern Shore this afternoon.
These will move off to the east-northeast through the rest of the
area into early this evening. QPF is under a quarter inch.
Mid-upper level moisture largely departs early tonight...leaving
lo levels moist. Winds diminish...and potential exists for
low cigs/vsbys developing...esp inland. Otherwise...PoPs to be
20-30% w/lows from 60 to 65.
A second s/w will be tracking NE in SW flow aloft...initially
invof TN/OH Valleys by late tonight...then to the local area by
Wed afternoon. Precipitation chances increase from the west. SPC
has outlooked our area with marginal risk of severe with damaging
winds being the main threat. Most of our area will considerable
cloud cover so instability may be limited, but there will be
moderate shear. For now, have chance for thunderstorms generally
east of Interstate 95 but will need to monitor. High temperatures
warm to around 70 to 75 across most of the area on Wednesday
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
The cold front pushes acrs the area and off the coast Wed ngt into
early Thu morning, with showers and a slgt chc for tstms. Gusty
winds and heavy downpours a possibility with any tstms. Clearing
out fm WNW to ESE later Wed ngt into Thu morning, as WNW flow
behind the front ushers drier air into the region. Lows Wed ngt
will range fm the upper 40s NW to the upper 50s SE.
Dry wx then expected Thu thru Fri, as a dry westerly flow
dominates the area, as high pressure gradually builds toward the
region fm the WNW. Generally mostly sunny both days, with highs on
Thu in the lower to mid 60s, and cooler on Fri with highs in the
lower to mid 50s. Lows Thu ngt will range fm the mid 30s to the
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Cool high pressure is expected to be centered from the
Mississippi Valley through the Southeast Conus Friday night into
Saturday. High pressure builds over the Mid-Atlantic region
Saturday night into Sunday as a split flow pattern develops aloft,
with a srn stream system tracking along the Gulf Coast States, and
a nrn stream wave diving into the Upper Midwest. This will result
in dry conditions under a mainly clear sky, although high clouds
may increase by Sunday. Temperatures are expected to be slightly
below seasonal averages, but within -1 st dev. Forecast lows
Friday night and Saturday night range from the low 30s inland to
the mid/upper 30s along the coast, with highs Saturday/Sunday in
the upper 40s to low 50s. GFS/ECMWF keep the srn stream system
south of the region Sunday night into Monday. However, the ECMWF
is more aggressive with the nrn stream wave, but the net result
may be minimal with respect to sensible weather as the system will
be moisture starved. High pressure returns later Monday into
Monday night, with low pressure approaching from the west during
the Tuesday/Tuesday night timeframe. At this time the 29/12z GFS
is about 12hrs faster than the 29/12z ECMWF.
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
A weak upper level impulse will bring scattered showers across
eastern Virginia and the Lower Maryland Eastern Shore this
afternoon. The precipitation will move off to the northeast by early
this evening. South winds will gust to around 20 to 25 knots through
the afternoon. An abundance of low level moisture will result in low
ceilings and visbilities at the TAF sites with highest confidence
over inland northern portions. Visibilities are expected to go no
lower than one mile but widespread IFR or LIFR ceilings are likely.
Conditions will be slow to improve Wednesday morning with plenty of
cloud cover and a low sun angle. It is possible that SBY and RIC
will remain IFR through 18Z. The forecast is for mainly dry
conditions overnight through 18Z Wednesday with only small chances
for showers at SBY and RIC.
OUTLOOK...As low clouds lift Wednesday afternoon...the chance for
showers increases Wednesday afternoon and night with a chance for
thunderstorms southeast portions. Mainly MVFR conditions are
indicated with short periods of IFR possible. Following a cold
frontal passage Wednesday night...the weather improves by Thursday
morning. VFR and dry conditions are forecast Thursday through Sunday
as high pressure slowly builds in from the west.
A trough is pushing through the nrn Mid-Atlantic this aftn
resulting in southerly flow of 15-25kt, with gusts up to 30 kt
over the lwr Bay and ocean. The trough lifts newd through New
England tonight with the wind diminishing quickly through the
evening and becoming sw 10-15kt overnight. Waves in the Bay are
generally 3-4ft, with seas ranging from 4-5ft s, to 5-7ft n. Waves
in the Bay subside to 2-3ft tonight. However, seas likely remain
4-6ft. SCAs continue for the Bay/lwr James/Sound through 7 pm,
with flags for the ocean running through Wednesday night to
capture lingering seas and the next southerly surge.
A cold front is expected to push through the Ohio Valley
Wednesday and then push off the Mid-Atlantic Coast late Wednesday
night. The wind should shift to south Wednesday into Wednesday
evening and increase to 15-25kt. It is likely that another round
of SCAs will be necessary for the Bay/Sound/rivers, but will let
the current headlines expire before re-issuing. The wind becomes
westerly at 10- 15kt (minimal CAA) behind the front late
Wednesday night into Thursday. A nw wind of 10-15kt/15-20kt ocean
should prevail Friday into Saturday as high pressure builds across
the Southeast Conus and low pressure persists over Atlantic
Canada. High pressure builds over the region Saturday night into
Sunday. Seas subside from 3-4ft to 2-3ft, with ~2ft waves in the
MARINE...Small Craft Advisory until 7 PM EST this evening for
Small Craft Advisory until 6 AM EST Thursday for ANZ650-652-