Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 260553
Area Forecast Discussion
National Weather Service Wakefield VA
153 AM EDT FRI AUG 26 2016
High pressure will continue to influence the weather across the
Mid Atlantic region through the weekend into next week. Warmer and
more humid conditions will prevail.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
High pressure will promote mainly clear and dry conditions across
the region tonight. Dew pts are up a couple more degrees compared
to this time yesterday...and so expect a warm night with lows in
the low/mid 70s.
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
The approaching weak cold front is expected to push through the
area Fri aftn/evening. Despite anticipated sct aftn cumulus
development and slowly increasing dewpoints ahead of the front,
deep moisture/lift is shallow and very limited by stable
conditions above 850mb. Therefore, confidence for isolated
showers/storms is low. As per the past several days, clouds will
dissipate and clear around sunset. Temps warm to 90-95F with
dewpoints mainly in the low 70s. As a result, heat index values
will creep into the low 100s but heat advisory criteria (104-109F)
is not anticipated (except maybe at a couple of unreliable AWOS
The front moves well offshore of the Mid Atlantic coast by Sat
morning and extends down to the Southeast coast. Any potential
shower activity will likely stay shunted south of the area due to
high pressure returning to the region. Little airmass change
anticipated in the post-frontal environment. Therefore, dewpoints
in the low 70s (upper 60s possible far nw counties) and slightly
cooler temps in the low 90s will be commonplace. Heat index values
may touch 100 degrees for an hour or two in far SE VA and inland
NE NC east of the Chowan River but will be patchy at best.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Medium range forecast period characterized by continued dry/warm
conditions for much of the period, courtesy of persistent
mid/upper level (Subtropical) ridge that becomes anchored over the
Southeast and Mid-Atlantic. (Low) Rain chances slowly creep back
into the forecast by the middle of next week.
There remains good support amongst the deterministic models, and
many of their respective member ensemble means, that the upper
level ridge will remain in place through midweek, even as it
dampens overhead Tue/Wed. Resultant low-level flow over the local
area veers from E-NE Sunday and Monday, to the W-NW Tue-Wed. Model
differences ramp up significantly for the latter half of next
week, and center mainly around the fate of tropical disturbance
Invest 99L in the Northern/Central Caribbean. There remains
support for tropical energy to push across the Bahamas and
eventually the Florida Straits over the weekend, potentially
reaching toward the ne Gulf coast and parts of the Deep South
early next week. The operational 12z/25 GFS now is a bit closer to
the latest 12z/ECMWF solution, albeit still weaker. Either way,
there remains no strong support for widespread pcpn over the local
area thru Wed. However, given the trends of continued breakdown of
the upper ridge overhead and gradually increasing PW values,
continued inclusion of a slight chc to low end chc (20-30%) for
iso to sct showers/tstms is reasonable and has been maintained in
the forecast for Wednesday and Thursday. Rain chances will remain
highest over the southern third of the area.
Temperatures should average at or above normal through the period.
Forecast highs Monday through Wednesday range from the mid 80s at
the coast to the upper 80s/low 90s inland. Early morning lows
through the period average in the upper 60s to mid 70s.
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --High pressure is situated off the coast early this morning with a
weak cold front well to the nw of the area over the Ern Great
Lakes. This will promote a light ssw wind early this morning,
which should largely inhibit fog formation. Some patchy ground
fog is possible at SBY, but confidence is not high enough to
include in the forecast. The weak front will continue to approach
from the nw today and pass off the Mid-Atlantic coast tonight. The
wind will be light today as a lee-side thermal trough develops
over the area with sct aftn cu. The front will dissipate this
weekend as high pressure aloft builds over the area. This high
will continue to prevail through Tuesday maintaining dry and vfr
-- End Changed Discussion --
Latest obs reflect Southerly winds ~10-15 kt this afternoon. High
pressure will slide farther offshore through tonight. Expect a
modest surge with winds tonight, as pressure gradient briefly
tightens ahead of a very weak cold front, which approaches from
the nw late tonight and Friday. A brief period of near-SCA winds
are possible in the Bay tonight through about midnight. Will hold
off with SCA flags given very short duration of surge, and can
handle with Marine Statements as needed.
Winds remain southerly ahead of the front Friday, but diminish to
5-10kt, with pressure gradient quickly slackening as the front
drops across the area and washes out overhead early Saturday. High
pressure then settles off the New England coast and ridges south
across the region Sunday into early next week. This will translate
to a period of prolonged, albeit predominately sub-sca onshore
flow averaging 10-15kt early next week. Seas average 2-3ft Fri/Sat
with 1-2ft waves in the Bay, with seas increasing to 3-4 ft Mon/Tue,
with wavewatch favoring seas 4-5ft out well offshore.
Tropical cyclone Gaston is expected to track to a position east of
Bermuda by early next week. This should result in long period
swell propagating toward the coastal waters, with seas remaining
3-5ft, again highest out near 20nm.