Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 210616
Area Forecast Discussion
National Weather Service Wakefield VA
116 AM EST Sat Jan 21 2017
A frontal boundary will weaken as it stalls across the Mid Atlantic
region tonight. Low pressure over the nations mid section Saturday
and Sunday will intensify as it slowly tracks east across the Mid
Atlantic region Sunday night and Monday. The intense low will move
off the New England coast Tuesday.
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Low level moisture remains plentiful over the FA late this
evening...and w/ light/VRB winds and no mechanism to scour out
that moisture through the overnight...will continue to be cloudy
(widespread ST) and possible spotty -DZ. Will have patchy fog
across the FA w/ temperatures staying near the dewpoints.
Potential exists for at local VSBYs to fall to/below 1/2
SM...especially over central/interior srn VA-NE NC. Lows mainly
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
Not much change in synoptic features seen on Saturday as the fa
remains in between systems with weak high pressure overhead. Thus,
expect patchy fog/drizzle to continue into the morning hours with a
slow improvement (albeit remaining mstly cldy to cldy into the mid
day and afternoon hours). Moisture begins to increase from the
s/sw late. Will carry low chc shwrs across swrn most zones after
21Z. Mild despite no sun. H85 temps support highs from the mid-
upr 50s Delmarva to upr 50s-lwr 60s west of the Ches Bay.
Challenging forecast thereafter as model differences appear Saturday
night and continue through Monday. Given how dry the 12Z GFS is
compared to the previous run (basically dry through 12Z Sun), have
trended this forecast more in line toward a NAM/ECMWF blend where
shortwave energy moves NE Saturday night resulting in chc to likely
pops overspreading the fa. Data shows little instability but a decent
amount of Atlantic moisture getting entrained from the SE. Thus, could
see some mdt rainfall rates at times across the south. The high to
the north keeps nern zones with chc pops. Lows from the mid 40s
Delmarva to lwr 50s srn most zones.
Next shortwave tracks across the fa Sunday with categorical pops as
a good amount of lift and low level moisture is noted. Increasing
PW`s will result in mdt to locally heavy rainfall. Warm frontal
boundary progged to drift north to near the NC - VA border so
will keep slght chc thunder across southern half of fa during
the afternoon. Warm with highs in the upr 50s to lwr 60s north
to mid-upr 60s south.
Models continue to have trouble with the stacked upr level low
progged to slowly cross the region late Sunday night and Monday.
Categorical pops for shwrs Sunday night. Lows upr 40s - mid 50s.
At some point in time, a triple point low is forecasted to cross
Virginia. Current timing is Monday which will continue to produce
widespread shwrs across the north with a dry slot potentially
cutting off pcpn across parts of the area Monday afternoon.
However, enough instab noted to keep thunder mentioned across
the SE in the warm sector. Highs mid 50s to lwr 60s.
Qpf through Monday should average one to two inches with locally
higher amounts possible.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Upper low pressure lifts northeastward away from the region Monday
night and Tuesday, with precipitation chances winding down by
Tuesday morning. High pressure is expected to return Tuesday night
into Wednesday. A cold front associated with an upper low lifting
over eastern Canada is progged to push across the region late
Wednesday night and Thursday. Will hold onto slight chc to low chc
pops (20-30%) during this time. High pressure returns again next
Friday with temperatures falling back below normal for this first
time in awhile. Highs Tuesday mostly in the 50s. Highs Wednesday
from the mid 50s Eastern Shore to the low 60s inland. Thursday`s
highs back in the 50s, then cooling into the 40s next Friday.
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
Widespread sub-VFR conditions to start off the 06Z TAF period.
With a weak warm front in the vicinity, light/calm winds, and
abundant low-level moisture, low-stratus is prevalent with
pockets of low vsbys as well. Expect mainly IFR/LIFR conditions
through early/mid-morning, with improving cigs not until late in
the morng/aftn as winds become southerly and the next low pres
systm approaches from the sw. There will be a good chance for
showers tonight as aviation conditions again deteriorate.
OUTLOOK...Periods of rain, moderate to heavy at times, Sunday
through Monday will be accompanied by IFR conditions. As low
pressure moves off to the northeast...dry weather and a clearing
sky is indicated for Tuesday and Wednesday.
Winds remain E aob 10kt this afternoon into this evening before
becoming NE and N tonight. Long period swell will keep seas between
3-4 ft into this evening. Winds become E then SE Saturday with
speeds remaining 10kt or less. Seas 2-3ft; waves 1-2ft.
Winds become SE 10-15 kt on Sunday as the first of two low pressure
systems impact the region. Seas build to 3-4 ft, except up to 5 ft
southern outer waters. The second low pressure system begins to
impact the region Sunday night with winds remaining 10-15 kt, except
increasing to 20-25 kt north of Chincoteague early Monday morning. A
brief period of gale gusts is possible early Monday morning across
the northern coastal waters. However, models continue to push the
highest wind threat further north into DE/NJ. Seas 3-5 ft across the
south Sunday night, building to 5-8 ft off Ocean City by early
Monday morning. Low pressure lifts north through the interior Mid-
Atlantic during Monday before lifting north of the area on Tuesday.
Winds will vary from SE to SW 10-15 across much of the marine area
Monday, while generally remaining E across the northern coastal
waters and diminishing through the day from 20-25 kt down to 15 kt.
Seas build to 6-10 ft north while remaining 3-5 ft south. Winds
become NW all waters on Tuesday with SCA conditions probable,
especially for the coastal waters. Seas 4-8 ft.