Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 251942
Area Forecast Discussion
National Weather Service Wakefield VA
342 PM EDT SUN SEP 25 2016
High pressure over New England will extend south across the Mid
Atlantic region tonight and Monday. A strong cold front will cross
the region Tuesday. An upper level low will track across the area
later in the week.
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Cool air wedge in place across the area as high pressure drifts east
across New England. Latest models not as bullish with the wdsprd
moisture as drier air continues to filter south along the coast.
TSCTNS indicating the moist E-SE flow off the ocean will keep BKN-
OVC conditions across the piedmont with SCT clouds east to the Ches
Bay/Tidewater/nrn Outer Banks to CLR skies along the eastern shore.
Expect a dry evening. Some weak lift noted across the swrn most
zones (FVX-AVC) for some spotty light rain/drizzle to develop
after 06Z. Lows 55-60, 50-55 across the lwr Md eastern shore given
a mstly clear sky. Some patchy fog possible in areas that do clear.
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
The high moves off the New England coast Monday with the next front
approaching from the west late. Upper ridge flattens which should
slow the advance of the front and serve to break down the cool air
wedge during the afternoon. TSCTNS show the BKN clouds hold firm
west of I95 through much of the day with SCT-BKN clouds to the
east. Pcpn wise, light rain/drizzle across the swrn zones early,
a several hour break in pcpn chcs through 18z, then slght chc
shwrs once again mainly west of I95 ahead of the approaching
front. Highs in the mid to upr 70s.
Models continue to show a strong cold front crossing the area late
Monday night and Tuesday. Weak s/w energy progged along the boundary
as it crosses sern zones Tuesday afternoon. Good feed of moisture
along and ahead of it with PW`s climbing to around 1.75 inches.
Instability is marginal, but kept low chcs for thunder with the
actual fropa. Kept likely pops with the time frame for the most
wdsprd pcpn coming late Mon nite and Tue morning. Models show drier
air filtering across NWRN zones Tues afternoon to end pcpn. Kept
high chc pops across the SE. Lows Mon nite in the 60s. Highs Tues in
the 70s. QPF btwn 1/2 to 1 inch.
Forecast for the mid week period becomes problematic and will all
depend on the track and available moisture associated with a deep
anomalous upper level low progged to drop south from the great lakes
region. The cold front clears the coast Tues night so expect pcpn
to wind down across the fa with chc pops lingering along the coast
through the nite. Lows range from the mid-upr 50s across northern
zones to the mi-upr 60s sern zones. Chc pops Wed for now with the
highest pops across the SE. Highs in the 70s.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --Long term forecast is complicated by the presence of an upper-level
cutoff low over the eastern CONUS for the duration of the period.
This will lead to below normal temps and frequent chances for rain.
Difficult to time the precip this far out in time but at this point
the best chances will be Wed night/Thu (30-50% pops). As the cutoff
low slides NE through the period, the chances of rain will slightly
decrease through the end of the week. As for temps, highs will be in
the low/mid 70s each day with lows ranging from the mid 50s over the
Piedmont to the mid 60s near the coast.
-- End Changed Discussion --
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
Drier air from the north continues to filter south along the coast
this afternoon. This is resulting in VFR conditions with only SCT
SC along the Delmarva, SCT-BKN SC between 4-5K ft ivof the Ches
Bay, BKN-OVC SC between 3-5K ft across the piedmont. Nearest MVFR
cigs are across the mts. Models now showing only SCT clouds along
the coast tonight with differing solutions for RIC. Given the lgt
onshore flow and position of the high, decided to keep a BKN SC
deck around 4K ft at RIC through the night with SCT SC elsewhere.
Fog not expected to be a big issue tonight but can`t rule out some
ptchy MVFR VSBYS toward sunrise in areas where it does CLR. Any
pcpn is expected to be confined to the mts.
OUTLOOK...The next chance for widespread precipitation arrives
Monday night into Tuesday ahead of a strong cold front. Showers
will linger through the mid week period as an upper level low
tracks across the region.
-- Changed Discussion --Latest sfc analysis shows high pressure centered over the Mid
Atlc/NE states with a frontal boundary well south of the area. The
high will slide offshore tonight into Mon with onshore
flow continuing. 5-10 kt winds tonight increase to 10-15 kt Mon
as the pressure gradient increases slightly ahead of an
approaching cold front. The front drops into the area Tue with
winds becoming light/variable by late Tue as the frnt stalls and
weakens in the vicinity. Waves of low pressure then form along
the frnt through midweek, with winds staying blo sca thresholds.
Expect mainly 1-2 ft waves over the bay and 2-4 ft seas over
coastal waters through this period.
-- End Changed Discussion --
The Cashie River at Windsor remains in minor flood stage. The
river is forecast to slowly fall below flood stage by late this
afternoon. See FLSAKQ for details.