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Area forecast discussion 
National Weather Service Wakefield Virginia
402 am EDT Friday Aug 26 2016

Synopsis...
a very weak cold front will approach from the northwest today as
high pressure pushes farther offshore. This front will cross the
area tonight, and then dissipate Saturday into Sunday as high
pressure builds across the mid Atlantic and prevails into early next
week.

&&

Near term /until 6 PM this evening/...
current WV imagery and model analysis indicate a
mid/upper level anticyclone centered over the Tennessee Valley. At
the surface, high pressure is centered well offshore, with a weak
cold front over the ern Great Lakes, and a Lee-side trough over the
Piedmont. Temperatures early this morning average in the low/mid 70s
with dewpoints in the upper 60s to low 70s.

The mid-level high will build ewd across the region today, as the
weak cold front continues to approach from the NW. 850mb
temperatures rise to ~20c today, which should support highs in the
low/mid 90s. Dewpoints averaging in the 70-72f range should result
in aftn heat indices of 98-104f. There is little support for
convection today with warm temperatures aloft, and anticyclonic mid-
level flow. Partly to mostly sunny with sct aftn cu.

&&

Short term /6 PM this evening through Sunday/...
the front slides across the region tonight into
Saturday and loses its distinction as it settles into the Carolinas
Saturday. Any potential shower/tstm activity should stay south of
the region with high pressure building overhead. There is little
change in the airmass with highs inland in the low 90s. Slightly
lower temperatures are expected at the coast (mid/upper 80s) with
light onshore flow. Morning lows will generally be in the low 70s.

High pressure continues to prevail Saturday night. Drier air to the
north will result in lows in the mid/upper 60s with low 70s across
se portions of the area. Some moisture may sneak under the ridge
across the ern Carolinas Sunday. Given this, a slight chc pop has
been maintained across interior NE NC in vicinity of the sea-breeze
boundary. Highs Sunday range from the upper 80s to around 90 inland,
with mid 80s at the coast under a partly to mostly sunny sky.

&&

Long term /Sunday 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 east-NE Monday, to the west-northwest 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/European model (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 precipitable water 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 /08z Friday through Tuesday/...
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
conditions.

&&

Marine...
sub-sca conditions will continue through at least the next few days.
S/SW flow continues this morning ahead of an approaching weak cold
front. The front drops through the area tonight, with winds shifting
to the north/NE behind the front. Expect 1-2 waves over the Bay and 2-3
ft seas over coastal waters. Onshore flow below 15 kt will continue
for the duration of the weekend as high pressure builds north of the
region.

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.

&&

Akq watches/warnings/advisories...
Maryland...none.
NC...none.
Virginia...none.
Marine...none.

&&

$$
Synopsis...ajz
near term...ajz
short term...ajz/bmd
long term...mam
aviation...ajz
marine...mas

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