Area Forecast Discussion
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FXUS61 KAKQ 221937
Area Forecast Discussion
National Weather Service Wakefield VA
337 PM EDT Sat Oct 22 2016
Breezy conditions will subside across the area saturday evening as
high pressure over the Ohio Valley moves toward the middle Atlantic
into Sunday. This high will shift southeast of the area by Sunday
night, allowing another cold front to move across the area Monday.
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Other than the breezy conditions early due to the deep
mixed layer...it should be a very quiet and seasonablly cool night.
The numerical guidance is in good agreement in showing the center of
the surface high to stay south of the area tonight. This should
allow for enough of a pressure gradient across the area between the
low over Quebec and the high over the SE to keep the BL from totally
decoupling. As such...do not expect the lows to totally drop to the
current dew point (which are currently in the low-mid
30s...especially across the interior). Will therefore keep the lows
around 37 across the interior to lower 40s in the coastal plain
to the mid 40s near the coast. Cannot totally rule out a little
frost on rooftops tonight across the piedmont where the temp
touches 36 or 37...but unless the boundary layer decouples more
than forecast do not expect any widespread frost.
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
No major issues through Tuesday. The high pressure over
the Appalachians will shift to the south on Sunday allowing for warm
advection to develop across the area on Sunday into Sunday
night(with 850mb temps rising to +13c) ahead of another dry cold
front. This should allow temperatures to rebound to close to normal
or just slightly below normal on Sunday. Despite the cold fropa on
Monday, downslope warming will allow for the best CAA later Monday
Night which may allow temps to be even slightly warmer on Monday
compared to Sunday. More likely to decouple Monday night...but the
overall atmosphere will not be as cold as tonight. As such...it is
once again possible that there may be a few spots with patchy
frost across the interior...but most likely not anything
widespread with temps dropping into the upper 30s across the
piedmont. Temps will drop back into the mid 60s on Tuesday (as
850mb temps drop back to +6c). This cold front looks quite dry and
other than a gradual wind shift from WSW to NW on Monday and
perhaps a few more clouds...no significant weather is expected.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Strong canadian high pressure ridges down into the Mid Atlc
region Tue ngt into Wed ngt, as the center of the high moves
toward ern Canada. Continued dry but cool conditions. Lows Tue ngt
in the upper 30s to mid 40s most places. Highs on Wed ranging fm
the upper 50s to mid 60s. Lows Wed ngt in the 40s to arnd 50.
Low pressure will then track thru the Great Lakes and into nrn New
England Thu thru Fri. That low will pull a cold front acrs the
area and off the coast Thu evening thru Fri morning. At this time,
have 20-30% pops for showers late Thu thru Fri morning. High
pressure will return for later Fri thru Sat. Highs will range thru
the 60s on Thu. Lows Thu ngt in the upper 40s to mid 50s. Highs on
Fri and Sat will range fm the mid 60s to lower 70s. Lows Fri ngt
ranging fm the mid 40s to mid 50s.
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
As of 18Z, strong sfc lo pres was cntrd near the coast of Maine,
with upper low cntrd over extrm SE NY state. While, sfc high
pressure was cntrd over the Middle and Lower MS Valley. Gusty
NW winds will continue at the TAF sites into early this evening
with gusts between 25 and 30 knots, as the sfc low intensifies a
bit as it lifts nwrd acrs Maine. Otherwise, VFR conditions
expected thru Sun aftn. Diminishing winds and a mainly clear
sky overnight all areas (some gusts 15 to 20 KT at KSBY/KPHF
KORF/KECG still possible through midnight).
OUTLOOK...High pressure builds across the SE during Sun. A dry
cold front sweeps across the area on Mon, with high pressure
returning for Tue and Wed. VFR conditions dominate.
Strong northwest winds persist over the waters this afternoon as a
cool and dry air mass advects into the local area. Strong gradient
winds persist, with winds a few thousand feet aloft in the 20-30
knot range. Optimal mixing has resulted in either solid SCA
conditions or low end gale conditions this afternoon. Gale headlines
continue for the upper Bay and Coastal waters north of Parramore
Island for northwest gusts of 35 to 40 knots. Seas remain 4-6 feet
and waves 2-5 feet (highest northern Bay zones). The gradient ramps
up again tonight as high pressure builds into the Deep South. The
result will be another uptick in northwest winds, although not as
significant as last night. Have extended Gale headlines north of
Parramore Island through tonight for northwest winds of 25 to 35
knots. Few gusts to 40 knots. Elsewhere, northwest winds generally
15 to 25 knots with gusts around 30 knots. Seas remain 4-6 feet and
waves 3-5 feet. High pressure nudges northeast into the local area
Sunday, with winds becoming westerly and diminishing to 10 to 20
knots. SCA headlines have been extended into early Sunday afternoon.
Seas remain 4-5 feet in the northern coastal zones through Sunday
night. SCA conditions look to be short lived as low pressure tracks
across the Great Lakes Sunday and into the Northeast Sunday night.
Combination of a strengthening gradient and a cool/dry air mass
already in place will likely mix some of the stronger winds aloft to
the surface. Expect a southwest wind of 15 to 25 knots Monday
A trailing cold front associated with the Northeast low pushes
across the region Monday night with more SCA conditions expected.
High pressure builds in from the northwest Tuesday, with sub-SCA
conditions expected through mid week.
NOAA Wx-Radio Transmitter at Driver/Norfolk is back online.
MARINE...Small Craft Advisory until 7 AM EDT Sunday for ANZ633-635>638.
Small Craft Advisory until 1 PM EDT Sunday for ANZ631-632-634-
Gale Warning until 10 PM EDT this evening for ANZ630.
Gale Warning until 7 AM EDT Sunday for ANZ650-652.