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Area forecast discussion 
National Weather Service Wakefield Virginia
811 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 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 southeast to keep the bl from totally
decoupling. As 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 cold air advection 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 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 west-southwest to northwest on Monday and
perhaps a few more 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 /00z Sunday through Thursday/...
as of 23z, deepening low pressure over Maine will move north. High
pressure will remain over the southeast states through Sunday night.
A dry cold front is progged to pass through the mid Atlantic states
Monday. High pressure builds over the mid Atlantic states Tuesday
and Wednesday.

Northwest winds will diminish through the evening but at least a
light breeze will continue overnight. Outside of some scattered to
broken clouds at around 6k feet this evening in the sby area...
the sky will remain clear through the 00z taf period. Winds
increase during the day Sunday but will not be nearly as strong as
they were Saturday.

Outlook...dry weather will prevail through mid week with a chance of
showers approaching from the west late Thursday. No significant
morning fog is expected through midweek but there may be fog around
sunrise Thursday morning.


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 Small Craft Advisory
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. Small Craft Advisory headlines have been extended into early Sunday afternoon.
Seas remain 4-5 feet in the northern coastal zones through Sunday
night. Small Craft Advisory 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 Small Craft Advisory conditions expected.
High pressure builds in from the northwest Tuesday, with sub-Small Craft Advisory
conditions expected through mid week.


Akq watches/warnings/advisories...
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.


near term...mrd
short term...lkb/mas/mrd
long term...tmg

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