Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 260003
Area Forecast Discussion
National Weather Service Wakefield VA
803 PM EDT Tue Oct 25 2016
Cool Canadian high pressure remains over the region through
Wednesday. A cold front approaches from the northwest Thursday
afternoon and crosses the area during the evening. High pressure
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1037mb high pressure is centered n of the Great Lakes
this afternoon and is ridging sewd into the Mid-Atlantic region. The
sky is sunny this aftn with only a few cu over the Lower MD Ern
Shore. Temperatures are mainly in the low 60s across the region with
dewpoints in the 30s. The high continues to build in from the nnw
tonight. This appears to be the coldest night so far this season,
with lows ranging from the mid/upper 30s over much of the area, to
the low/mid 40s for coastal se VA/ne NC. This will bring the
potential for frost except along the coast. Some high clouds could
push into the Piedmont overnight, which could limit frost potential
for the Piedmont. The highest confidence for frost is over the MD
Ern Shore where a frost advisory has been issued. Patchy frost has
been highlighted in the HWO for the Piedmont and Interior Coastal
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Continued cool Wednesday under a partly to mostly sunny
sky. 850mb temperatures moderate to +3 ne to +7 sw. However, this
will be offset by the combination of high pressure over the region
and low-level ne flow, which will limit mixing. Forecast highs are
in the mid/upper 50s ne, to low 60s sw. The surface high gradually
pushes offshore Wednesday night as low pressure tracks toward the
Great Lakes. The surface ridge axis remains near the coast much of
the night, so lows will still be cool under a mostly clear to partly
cloudy sky ranging from the upper 30s over the Lower MD Ern Shore
to the low 40s elsewhere.
Shortwave energy will lift through the Great Lakes Wednesday night
into Thursday, with the trailing cold front approaching from the nw
Thursday aftn and crossing the area Thursday evening. Clouds
increase early Thursday with much of the area becoming mostly cloudy
to overcast. Chc PoPs (30-40%) for showers spread across the nrn
half of the area by afternoon. The better potential for showers will
be with the front Thursday evening, with ~60% PoPs from the Nrn Neck
to the Ern Shore, and 30-40% elsewhere. Moisture is limited with
this system, so current QPF through 12z Friday is aob 0.15". Highs
Thursday range from the low 60s nw to near 70 se.
The front pushes offshore late Thursday night into early Friday
morning, with high pressure returning by aftn. Clouds are expected
to decrease Friday with most of the area becoming mostly sunny by
late morning and aftn. Lows in the upper 40s to mid 50s Friday
morning will be followed by highs in the mid 60s to around 70.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Surface high pressure slides south of the region Saturday, centering
along the Southeast coast. Shortwave ridging aloft builds over the
eastern US. The result will be deep layer southwest to west flow and
warming temperatures. 850Mb temperatures warm to around 12-14C (+1
standard deviation) Saturday. Have trended temperatures warmer, with
highs generally in the low to mid 70`s. Cooler Eastern Shore. Medium
range guidance now in better agreement with pushing a northern
stream shortwave across the Northeast states Sunday. A dry cold
front is progged to drop into the region Sunday afternoon into
Sunday evening, but not before temperatures warm into the mid
(possibly upper) 70`s. Trough axis pushes offshore Sunday night
along with the dry cold front. Upper/surface high pressure returns
to the region Monday. Highs in the mi to upper 60`s. Heights begin
to build again across the Southeast and Mid-Atlantic as upper level
high pressure over the Gulf of Mexico builds northward. The result
will be another warming trend with highs back into the upper 60`s to
low 70`s Tuesday. Mild overnight temperatures expected through the
period, with lows generally in the upper 40`s to low/mid 50`s. The
exception will be Saturday night, when lows are in the mid to upper
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A ridge of high pressure extending south from Canada into the Mid
Atlantic States will dominate over the Mid Atlantic States through
the 00Z TAF period. This ridge will shift slowly toward the coast by
late Wednesday. Light winds will prevail through the period which
will gradually veer from northwest or north to northeast and
eventually to east to southeast at RIC.
OUTLOOK...High pressure slides off the coast late Wednesday night
into Thursday morning and there could be some patchy fog as low-
level moisture increases. A low pressure system moving from the
Midwest to the Northeast States will drag a cold front through the
region Thursday evening. High pressure returns Friday and Saturday
and settles off the coast as another cold front approaches from the
west on Sunday.
Latest surface analysis centers ~1028mb high pressure over central
Virginia. The result is a northwest wind of 10-15 knots over the
waters. Seas have dropped to 2-4 feet and waves 1-2 feet. All
headlines have been allowed to expire. High pressure remains west of
the waters tonight, with hi-res guidance indicating marginal SCA
conditions for the Bay. While the cool and dry air mass may support
stronger winds, the gradient is rather meager. Have opted to cap
winds at 15-17 knots in the Bay with no headlines anticipated.
However, cannot rule out a few gusts to 20 knots in the upper Bay.
Waves build to 2-3 feet tonight and seas 3-4 feet. The surface ridge
builds over the waters Wednesday and pushes offshore Wednesday night
ahead of the next cold front. Gradient ramps up Thursday resulting
in south to southeast SCA winds of 15-25 knots Thursday afternoon.
Waves build back to 2-3 feet and seas 3-5 feet. The front pushes
across the waters late Thursday night with SCA conditions expected.
Northwest winds increase to 15 to 25 knots. Waves 2-4 feet and seas
3-5 feet. High pressure returns to the waters Friday afternoon.
Medium range guidance now in better agreement with keeping high
pressure over the Southeast coastal plain Saturday and Saturday
night. A cold front crosses the waters late in the weekend into
early next week.
MD...Frost Advisory from 3 AM to 9 AM EDT Wednesday for MDZ021>024.