Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 220301
Area Forecast Discussion
National Weather Service Wakefield VA
1101 PM EDT SAT MAY 21 2016
Low pressure will track northeast and away from the mid Atlantic
coast tonight. A trough of low pressure will then linger over the
area Sunday and Monday. This trough will gradually move offshore
Monday night into Tuesday.
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
Latest surface analysis places 1005 low pressure off the Eastern
Shore this evening with weak high pressure over the eastern Great
Lakes. Light rain lingers over the Maryland Eastern Shore with
another area of light rain moving into the southern Piedmont. Flow
has become north to northwest, but low stratus remains locked in
place. The surface low deepens and pushes farther offshore tonight
as energy associated with the upper level trough tracks into the
region after midnight. Upper level support in tandem with moist
low levels and modest lift in the 295 to 300k theta surfaces
should support some patchy to scattered light rain or drizzle
over the northern local area. Due to recent rainfall and small
dewpoint depressions, expect patchy fog to develop area wide late
tonight through early Sunday morning. Do not anticipate dense fog
as soundings indicate some dispersal and mixing. Lows generally in
the mid to upper 50`s.
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Upr lvl lo pres will swirl invof fa Sun into Mon mrng...then begin
to sloly push to the E and offshore lt Mon through Tue. The wx
now occurring acrs the ern OH vly and wrn PA is the wx that is
xpcd here Sun into Mon (widespread cldns...w/ sct-likely -ra).
Moisture will be slo to push to the cst fm Mon aftn into Tue.
So...another 2 days of (much) blo normal temps...POPS avgg 30-60%
and considerable cldns. On Tue (esp by aftn)...xpcg a return to
partly sunny/warmer conds (esp inland)...not quite sure conds
improve too quickly nr the cst - esp on the Delmarva (before eve).
Highs Sun fm the l-m60s N and cntrl areas to m-u60s S. Lows Sun
ngt in the l-m50s. Highs Mon in the u60s to l70s. Lows Mon ngt
mnly in the m50s. Highs Tue 75-80F inland to 70-75F at the cst.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Sfc high pressure settles off the Southeast Coast as upper level
ridging resides directly over the entire East Coast Tue night
through Thu. Developing sw flow Thu night/Fri will likely open the
door for increasing humidity and rain/thunderstorm chances Thu/Fri
aftns as conditions become increasingly unstable. Overall, high
temps should run around 5-7 degrees above normal Wed-Fri. Highs
generally in the mid 80s (mid 70s-low 80s beaches). Low temps also
running about 5 degrees above normal Wed/Thu night. Seasonal lows
Tue night in the mid 50s nw to lower 60s se.
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A moist and unsettled pattern will continue at the TAF sites during
the 00z TAF period. Low pressure was slowly deepening off the Mid
Atlantic Coast and moving to the northeast as a general area of low
pressure from West Virginia to the Carolinas was filling. An upper
level low pressure system over northern Ohio will deepen and reach
eastern North Carolina by Monday. The upper low and associated
trough will slide off the coast by Tuesday.
As of 00Z...IFR conditions were present at all the TAF sites except
ECG. These mainly due to low ceilings though SBY also had an IFR
visibility. Expect conditions to deteriorate overnight with ceilings
mainly lowering to LIFR and visbilities to IFR except MVFR at ORF
and ECG. Kept SBY no lower than 1 mile but it could easily fall
below that overnight.
Conditions improve during the day Sunday. Have gone on the
optimistic side of the MOS guidance as recent experience has
indicated that the models are too low with the ceilings when the
center of an upper low becomes centered over the area which will be
the case on Sunday (and Monday). Have most of the TAF sites
improving to MVFR during the afternoon.
OUTLOOK...The chance for showers continues Sunday night and Monday.
Flight conditions will slowly improve with VFR/MVFR expected outside
of some patchy IFR fog early Monday morning. High pressure builds
over the Mid Atlantic States with mainly dry weather late Tuesday
-- Changed Discussion --SCA in effect through 4 AM EDT for the Chesapeake Bay from Smith
Point to Little Creek VA due to northwest to north winds up to 20
Sfc low pressure located about 50-70 miles east of the VA/NC
border late this aftn. The low will continue to track ne tonight
as an upper trough swings into the Mid Atlantic Region...allowing
ne winds aob 15kt and onshore swell to persist during this time.
Seas currently 6-8ft srn waters/4-6ft nrn waters. As the low
tracks newd...seas will build to 6-8ft and subside to 4-5ft south.
Waves on Ches Bay averaging 2-3ft with up to 4ft in the mouth of
the Bay due to 4-5ft onshore swell. SCA flags remain in effect for
the Bay through 600 am Sun morning. See next paragraph regarding
SCA flags for coastal waters.
The trough moves overhead on Sun and becomes a closed low spinning
over the region. Meanwhile, a frontal boundary from the exiting
sfc low will stall along the Carolina coast and another sfc low is
expected to develop invof Cape Hatteras. This feature is expected
to get pulled nwd just off the Mid Atlantic coast Sun through Mon
before moving north near the srn New England coast Mon night into
Tue. A brief lull in ne-e winds aob 15kt anticipated Sun with
winds becoming n 15-20kt Bay/Sound/coastal waters (gusts to around
25kt coastal waters) after midnight Sun night through most of Mon
with another round of SCA conditions expected. Seas on Sun begin
at 3-4ft srn waters/4-6ft nrn waters and then average 4-5ft all
coastal waters by late Sun aftn...only to build to 5-7ft srn
coastal waters/4-6ft nrn coastal waters after midnight Sun night
into Mon. SCA flags have been extended for all coastal waters
through early Mon evening although they will likely be extended
into Tue for seas above 5ft. Anticipated SCA flags for Bay/Sound
will need to be hoisted during a later forecast pkg issuance time
as they will extend into the 4th period.
Conditions quiet down Tue night through Thu as high pressure at
the sfc and aloft build over the region. Generally sw winds around
10kt or less should be anticipated. Seas average 2-3ft Tue night
and then 2ft Wed/Thu. Waves average 1-2ft.
-- End Changed Discussion --
-- Changed Discussion --MD...None.
MARINE...Small Craft Advisory until 6 AM EDT Sunday for ANZ634.
Small Craft Advisory until 4 AM EDT Sunday for ANZ630>632-638.
Small Craft Advisory until 7 PM EDT Monday for ANZ650-652-654-
-- End Changed Discussion --