Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 260055
Area Forecast Discussion
National Weather Service Wakefield VA
855 PM EDT Tue Apr 25 2017
Low pressure tracks northeast along the Mid Atlantic coast tonight,
then slowly moves offshore Wednesday. High pressure builds into the
area Thursday. A cold front stalls north of the region Friday.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Latest MSAS has the center of the filling low over the NC coastal
plain and is progged to move NE tonight reaching a position off the
eastern shore after 06Z. High res data combined with the latest
radar trends would favor the highest pops along coastal sections
this evening. Will carry likely pops there with chc pops elsewhere.
Thunder chcs along an E of I95 through sunset then along the coast
through midnight as the low drifts NE. Systm slow enough for moisture
to linger through most of the night across the fa. Thus, kept chc pops
after midnight. Concern then turns to the potential for fog development
due to wet ground and warm temps. Will carry patchy fog in grids for now
(except areas of fog ivof OXB, SPS currently in effect) and allow the
evening shift to adjust the grids as needed. Lows 55-60.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
The low is progged to be east of Cape May NJ by 12Z Wed then slowly
pulls NE away from the region as an upper level ridge builds in from
the west. Thermal soundings cont to show some mid level moisture
trapped beneath a strong subsidence inversion aloft, which will help
keep clouds around most of the day across eastern zones. Even enough
lingering moisture around for sct showers through 15Z or so along
the eastern shore. Appears enough subsidence across the west for
skies to become partly to mstly sunny after 18Z. Highs 75-80 west of
the bay, upr 60s-lwr 70s along the coast.
Mostly clr / pt cldy Wed nite. Lows in the upr 50s to lwr 60s.
Ridge axis slides offshore ahead of an approaching cold front
Thursday. Increasing return flow and 850mb temps around +14 to +16C
(around +1 standard deviation) result in warm and dry conditions.
Highs in the mid 80s west of the bay, upr 70s-lwr 80s eastern shore,
cooler at the beaches.
Models differ a bit in returning moisture across the mts Thurs nite.
Appears a weak trof moves east producing low chc shwrs after 06Z.
Lows in the 60s. Weak trof pushes east Fri morning. Will keep slght
chc pops thru noon, then dry. Highs in the low to mid 80s except
remaining in the 70s at the beaches.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Temperatures are expected to remain well above normal through
the weekend as an upper level ridge remains anchored over the
Ern Conus. 850mb temperatures ~18C will support highs in the
upper 80s to around 90 Saturday (75-80F at the immediate coast)
after morning lows in the mid/upper 60s. A weak front will knock
high temperatures down a few degrees Sunday over the Ern Shore, with
low 80s expected and mid/upper 70s at the immediate coast. Meanwhile,
highs W of the Bay will once again be into the upper 80s.
Aftn/evening chances for showers/tstms Saturday/Sunday will be low
and mainly aob 20%. A cold front approaches from the W Monday.
Forecast highs Monday are in the low/mid 80s after morning lows in
the mid/upper 60s. 25/12z GFS/ECMWF/CMC support the best chc for
showers/tstms very late Monday aftn into Monday evening and shifting
to the coast late Monday night. Temperatures trend back toward
normal Tuesday with highs in the 70s.
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --Low pressure near Va Beach continues to move slowly north and
is expected to hug the coast as it moves off the Delmarva and NJ
coasts overnight. Widespread IFR ceilings will again develop
overnight across the CWA. Showers and a few tstms will affect
mostly the eastern portions of the CWA...generally from Caroline
County to Richmond to Emporia...during the overnight hours. Some
of these showers and tstms may produce periods of brief heavy
Stratus and widespread IFR ceilings are expected to redevelop
overnight as moisture wraps around the backside of the low pressure.
Guidance has also been persistent with the development of patchy fog
tonight and into tomorrow morning. Included MVFR visibilities for
tonight, but it is possible IFR visibilities may develop in a few
locations. Conditions will improve during the day on Wednesday,
returning to VFR Wednesday afternoon.
Light easterly flow is expected to continue through this
evening. Winds will shift to the W/NW as the low departs the
area tonight and Wednesday. Winds remain light on Wednesday,
generally 5-10 knots.
Outlook: Aviation conditions improve through the day on Wednesday
with VFR expected to return to the area. A shower or thunderstorm
will be possible during the day on Friday, but otherwise, VFR and
dry conditions should dominate the extended period.
-- End Changed Discussion --
Latest sfc analysis shows strong sfc low pres near the VA/NC coast.
With the low directly over the area, winds have diminished this
aftn to mainly sub-sca criteria. Waves and seas remain elevated
however, with 4 ft waves expected to continue over the mouth of
the Bay for another few hours and seas aoa 5 ft through daytime
Wed for southern coastal wtrs and through Wed night for
northern coastal wtrs. Also, a high surf advsry will remain in
effect for the Lwr Eastern Shore beaches until early this eveng
as nearshore waves remain ~8 ft. The sfc low pulls NE of the
area late tonight into Wed with winds avgg aob 10 kt and seas
slowly subsiding. Quieter marine conditions towards the end of
the week with persistent S/SW flow over the area until early
next week when the next cold front crosses the region.
Current tidal departures continue to average around 1.0 to 1.5
feet, with strong low pressure pushing up the Mid Atlc coast.
With the high tidal anomalies and new moon tomorrow, expect many
areas to reach minor flooding tonight. Have hoisted several
coastal flood advisories and statements to account for this.
Think this tide will have the highest water levels this week,
but still cannot rule out some areas getting to minor again
-- Changed Discussion --MD...Coastal Flood Advisory until 11 PM EDT this evening for MDZ024-
Coastal Flood Advisory from midnight tonight to 6 AM EDT
Wednesday for MDZ021>023.
VA...Coastal Flood Advisory until midnight EDT tonight for
Coastal Flood Advisory until 2 AM EDT Wednesday for VAZ089-093-
Coastal Flood Advisory until 11 PM EDT this evening for VAZ099-
MARINE...Small Craft Advisory until 7 AM EDT Thursday for ANZ650-652-
Small Craft Advisory until 7 PM EDT Wednesday for ANZ656-658.
-- End Changed Discussion --