Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 070045
Area Forecast Discussion
National Weather Service Wakefield VA
745 PM EST Tue Dec 6 2016
A complex area of low pressure moves off the Mid Atlantic coast
tonight with high pressure building in from the west Wednesday.
A strong cold front crosses the region Thursday. Canadian high
pressure builds into the area for the weekend.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Latest MSAS places the coastal low near ILM with the upper level
trof just west of the mts. Radar has widespread light to ocnl mdt
rain moving NE across the region although a punch of mid level dry
air has held down rainfall amounts. Models have the coastal low
becoming the main synoptic feature with a track NE along the Outer
Banks this evening then moving east out into the Vacapes and pulling
away from the coast after midnight. Meanwhile, high res data tracks
the upper level system and associated (light/mdt) pcpn SW-NE across
the area late afternoon and evening with pcpn tapering off to some
drizzle before ending SW-NE after midnight as the lift shifts
offshore. Thus, will continue to carry categorical pops into the
evening with pops ramping down late this evening across the west
and after midnight over the east. Areas of fog will be noted due
to the abundant low level moisture. Additional qpf between 1/10th
to 1/2 in possible. Lows range from the mid 30s NW to upr 40s SE.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Weak high pressure builds across the region Wed. Downsloping flow
will aid to dry the column out. Thus, morning clouds should give way
to a pt to mstly sunny afternoon. Near seasonable temperatures with
highs in the mid 50`s. Anomalous northern stream low builds into
southeast Canada Wed night as the associated trough digs into the
eastern US. A strong, fast moving cold front will reach the central
Appalachians by late Wed night. Clouds increase, but dry conditions
expected thru 12Z Thurs. Lows 35 to 40.
Models continue to push the strong cold front across the area Thurs
as the trough axis lags behind. Moisture will be limited with PW`s
at or below three quarters of an inch. While the front is progged to
outrun the best height falls, models continue to show a line of
showers along the boundary. Will maintain low chance pops, with the
focus for shwrs shifting to the eastern half of the fa Thurs aftrn.
Highs in the 50s.
Dry and colder Thurs night and Fri as Canadian high pressure builds
east. Lows Thurs night in the mid-upr 20s except lwr30s along
thecoast. Highs Fri in the lwr 40s.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Long term period starts off Fri night/Sat with dry weather as sfc
high pressure builds directly over the Mid Atlc. Main story in the
extended will be cold temps, with lows in the low/mid 20s Fri night
and Sat night. High temps Fri and Sat avg in the low 40s both days.
Next chance of pcpn arrives Sun night/Mon with an approaching cold
front, with the best chance of rain being during the day Mon based
on the 12Z GFS/ECMWF (40% pops). High temps Mon in the mid/upr 50s.
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --As of 00Z...Winds were in the process of turning to the north and
northwest across the TAF sites as low pressure moves off the coast
near the VA/NC border. Temporary improvement in ceilings is expected
to become solidly IFR/LIFR ceilings late evening. Precipitation will
quickly end from the west.
Guidance indicates IFR ceilings continue into the early afternoon...
toward the coast due to a moist northerly flow in the low levels.
OUTLOOK...A strong cold front impacts the area on Thursday, with
only a quick chance for showers Thursday afternoon. High pressure
returns Friday through Sunday.
-- End Changed Discussion --
Latest sfc analysis shows low pressure developing near the NC coast
with another area of low pressure over the OH Valley. The former low
will strengthen this eveng/tonight as it pushes off the coast.
Expect strong SCA conditions over at least the Bay and ocean with
this system, with occasional gusts to gale force possible. Will
maintain the SCA for now. Seas may reach 7-9 ft out 20 nm.
Winds/waves/seas then drop during the day Wed as weak high pressure
builds into the area. Sca conditions may linger until Wed eveng over
the ocean with 5 ft seas continuing. A strong cold front then pushes
across the waters Thu, with at least strong SCA conditions expected
Thu night through Fri night. Sub-SCA conditions return over the
MARINE...Small Craft Advisory until 1 AM EST Wednesday for ANZ635>638.
Small Craft Advisory until 10 AM EST Wednesday for ANZ630>634.
Small Craft Advisory until 10 PM EST Wednesday for ANZ650-652-