Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 202359
Area Forecast Discussion
National Weather Service Wakefield VA
759 PM EDT Thu Oct 20 2016
A cold front approaches from the west tonight and crosses the
region on Friday...followed by breezy and much cooler, more
seasonable conditions Friday night through the weekend.
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Latest sfc analysis shows a frontal boundary over the OH Valley,
low pressure well east of FL, and high pressure centered over SE
Canada. The cold front approaches from the west tonight, with dry
conditions expected ahead of the front and some increasing clouds
late. Otherwise, included some patchy fog with calm/light winds.
Low temps in the lwr 60s.
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
After several recent dry days, shwrs are likely across the area
Fri as a cold frnt and associated mid-level shortwave trough cross
the Mid Atlc. The frnt has slowed down a bit with the latest
guidance, so expect the rain to not start along the I-95 corridor
until early-mid aftn, and closer to the coast late aftn-early
eveng. PoPs are 60-70% most areas. Kept thunder out of the
forecast as well, with most areas expected to only receive a
tenth to a quarter inch of qpf. Temps Fri lwr than previous
days...highs mainly in the 70s...highest over eastern areas.
Chances of rain decrease fm west to east Fri evening as the frnt
pushes offshore and drier air moves in from the west. Low temps
Fri night mainly 45-50F. Dry wx with decreasing clouds for Sat
with much cooler conditions under strong caa...high temps only in
the low-mid 60s. Winds will be highest along the coast Fri
night/Sat where sustained winds will average 20-25 mph with gusts
of 30-35 mph. Farther inland, gusts will average 20-25 mph.
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
High pressure settles across the sern states Sat night and Sun as
intense low pressure moves into eastern Canada. Dry with slowly
diminishing winds Sat nite. Lows in the low to mid 40s except upr
40s to lwr 50s sern coastal areas. Highs Sun in the mid 60s. Lows in
the upr 40s to lwr 50s.
Next cold front crosses the region Monday. No significant moisture
noted so expect a dry fropa. CAA lags so expect a milder day with
highs in the upr 60s to lwr 70s. Lows in the 40s except lwr 50s sern
Canadian high pressure builds across the area for the mid week
period. Remaining cool and dry. Highs Tue 60-65. Lows in the 40s to
lwr 50s sern coastal areas. Highs Wed in the 60s. Lows in the mid
40s to lwr 50s.
Low pressure progged to move from the nations mid section Wed to the
Gt Lakes region Thurs. Limited moisture returns in advance of the
approaching warm front. Added slght chc pops Thu across the northern
half of fa with this feature. Highs 65-70.
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --As of 23Z...High pressure remains centered over Atlantic Canada
with weak low pressure lingering to our west over portions of
the Cumberland Plateau. Low pressure is still expected to
gradually lift to the northeast tonight as a strong upper level
trough digs across the Midwest. Weak high pressure will linger
near Mid- Atlantic coast tonight before a cold front approaches
the area Friday afternoon.
Tricky forecast tonight with the potential for fog development.
Weak high pressure near the coast and modest low-level moisture
will bring the potential for IFR/stratus at all TAF sites
tonight. Guidance continues to show the most favorable fog
development near the coastal sites with less confidence further
inland. As with the previous couple of mornings, conditions
should begin to improve after 14Z. A trough and associated cold
front will approach the area during the afternoon. Am expecting
some shower activity to work into RIC after 18Z and continue to
move west to east across the area. Winds will flip towards the
west/northwest and begin to increase Friday afternoon.
Outlook: High pressure will build back into the region late in
theday on Saturday and into Sunday. Another cold front (dry
frontal passage) will sweep across the area Monday before high
pressure makes a return on Tuesday.
-- End Changed Discussion --
Return S-SW flow around high pressure off the sern coast results
winds below 15 kts through mid day Fri. Latest guidance has slowed
the cold frontal passage down by about 2-3 hours Fri aftrn. Thus,
made a few tweeks in the SCA headlines for the rivers. Pushed back
the starting time until 22Z which comes up Fri eve rather than Fri
aftrn. Went ahead and extended the SCA headlines for the rivers and
Currituck sound through Sat aftrn (end of 4th period).
Most if not all guidance points to a strong CAA surge late Fri night
into Sat morning across the Ches Bay and coastal waters. Given
rather sharp pressure rises behind the front, 925-950 MB winds
between 35-40 kt, falling H85 temps and water temps arnd 70F,
confidence is high that enough mixing occurs to upgrade the gale
watch to a warning with this package. Even the old "Boston
Technique" suggests the strongest gusts (up to 40 KTS) across the
northern waters with gusts to 35 KT across the south. Gusts to 35 KT
possible for a few hours late Fri nite across the NC coastal waters
so went ahead and added them to the gale warning. The offshore NW
flow will keep seas from building to anything higher than 5-7 ft
most areas (highest out 20 NM offshore). Bay waves build to 4-5 ft.
Winds remain elevated Sat night and Sunday but should diminish to
The next front crosses the area Mon. Appears another surge (albeit
much weaker) will likely require minimal SCA headlines late Monday
or Monday night.
Record high temperatures for today are listed below:
RIC 89 (1984)
ORF 87 (1984)
SBY 84 (1984)
MARINE...Small Craft Advisory from 6 PM Friday to 4 PM EDT Saturday for
Gale Warning from 8 PM Friday to noon EDT Saturday for