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000
FXUS61 KAKQ 181545
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
1145 AM EDT Fri Aug 18 2017

.SYNOPSIS...
A warm and humid air mass remains in place across the Mid-
Atlantic states today on continued south flow. The next cold
front will arrive late tonight and exit the region by Saturday
morning. High pressure builds in for Saturday night through
early next week.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
Initial showers that developed early this morning are
dissipating quickly and the low stratus deck that has been
in place for most areas except along coastal areas of the
Tidewater and NE NC is quickly dissipating too. As a result the
sun will be coming out and temperatures will quickly jump into
the upper 80s and continue up into the low 90s for most areas.
Ahead of the cold front, seeing lots of clear sky across wrn VA
so warming should continue through the afternoon hours. With
dewpoints in the mid 70s to around 80 will see heat indices from
around 100 to 109 across the area. The highest values will be
across SE along the Ches Bay from the Middle Peninsula southward
into NE NC. So have issued a heat advisory for that area for the
rest of the afternoon.

Still looks like afternoon convection will form this afternoon
across wrn VA and then head ESE across the region. The 12z NAM
is more enhanced with the convection so will need to monitor for
possible severe as cape is now forecast to between 3000 - 4000
J/kg. The winds aloft are not extremely strong and the direction
shear is minimal. The mostly likely threat would be wind damage
from downburst.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
The front slowly pushes southeast early Saturday, and models
have once again trended a bit faster with the frontal passage,
allowing for a quicker end to showers Sat morning.

A strong shortwave trough sweeps across the Mid-Atlantic States
Saturday night, but it remains north of the area and with the
low level moisture gone, not anticipating much except some mid
level clouds. By Sunday, high pressure will be over the region
with dry and seasonable weather in place.

For temperatures, will continue to see near normal weather with
highs in the upper 80s to around 90 each day and lows in the low
to mid 70s each night except for Saturday night when the drier
air will allow temps to drop into the upper 60s to low 70s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
Sfc high pressure builds north of the area with stacked high
pressure residing off the Southeast Coast through Mon night.
A thermal trough develops in the lee of the Appalachians for
Tue/Tue night, and then a cold front is expected to track
through the area on Wed...exiting the coast late Wed night.
Conditions will become increasingly more humid with each
passing day. Sfc features rather diffuse for Mon, however
seabreeze boundaries with the presence of ample moisture will
keep a slight chance for showers/storms in the forecast...
primarily for the aftn/early evening. Thunderstorm activity
expected to become widely scattered Tue as convection develops
invof lee trough. The frontal passage Wed/Wed night will
provide a better focus for more organized thunderstorms to
occur. Highs Mon-Wed generally upper 80s to lower 90s;
low-mid 80s beaches. Lows Sun-Tue nights generally 70-75F.
Lows Wed night mid-upper 60s NW to 70-75F SE.

&&

.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
Low stratus across terminals this morning with IFR/MVFR cigs at
RIC/SBY/PHF/ORF. Expect stratus to slowly scour out through
13-14z, with an improvement to VFR at all sites by 15-16z.

A cold front approaches the region today, with showers and
thunderstorms developing and becoming more widespread by this
evening into Saturday morning. This will bring another chance
for sub-VFR conditions late in heavier showers, mainly
RIC/SBY/PHF. Confident enough to throw showers and vicinity
thunder wording in at RIC/SBY, but will keep thunder mention
out for now at ORF/PHF.

Outlook: VFR conditions returns later Sat through the weekend as
High pressure builds back into the region. Some early morning
fog possible both Sunday and Monday mornings.

&&

.MARINE...
Latest sfc analysis shows weak high pressure offshore with a cold
front over the OH Valley. This front will track east towards the Mid
Atlc today, with southerly flow increasing ahead of the front as the
pressure gradient increases. By this aftn/eveng before the fropa
conditions will be close to SCA criteria over Bay due to ~15 kt
sustained winds and northern cstl wtrs due to 4 ft seas. Not
confident enough that SCA conditions will occur to issue headlines
attm. The cold front drops into the wtrs tonight, with shras/tstms
psbl and winds/waves/seas decreasing thereafter. For Sat, with the
front weakening in the vicinity, expect winds aob 10 kt by the aftn
with 1-2 ft waves over the Bay and 2-3 ft seas over cstl wtrs.
Similar conditions into Sun with little change in the overall
pattern. Sub-SCA conditions will continue into early next week with
weak sfc high pressure in the area.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...Heat Advisory until 8 PM EDT this evening for NCZ013>017-
     030>032.
VA...Heat Advisory until 8 PM EDT this evening for VAZ084-089-090-
     093-095>098-523>525.
MARINE...None.

&&

$$
SYNOPSIS...MAM
NEAR TERM...ESS/MAM
SHORT TERM...ESS/MAM
LONG TERM...BMD
AVIATION...MAM/JAO
MARINE...MAS