Area Forecast Discussion
Issued by NWS Wakefield, VA

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785
FXUS61 KAKQ 230126
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
926 PM EDT SUN MAY 22 2016

.SYNOPSIS...
Low pressure lingers over the Mid Atlantic through Monday, then
gradually moves offshore Monday night into Tuesday. High pressure
builds in from the west for the rest of the week.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Next batch of wrap around pcpn now beginning to take shape with
the latest radar trends showing rain/drizzle beginning to fill
back in and expand south across the northern half of the fa this
evening. All model data suggests this southward trend continues
through the overnight hours as the upper trof will close off as it
settles over sern Va late tonight. Went ahead and increased pops
to categorical/likely across Va west of the bay with likely/high
chc elsewhere. The steady pcpn will likely wait until after
midnite to reach southern areas. Also added areas of fog with the
rain/drizzle. Don`t think vsbys get low enough for dense fog but
low enough to include in both the land and marine forecasts. Lows
only a few degrees away from the current readings of low-mid 50s.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
Upper level low will continue to slowly wobble off of the mid-
atlantic coast through the day, eventually sliding offshore by
monday night. This will produce more in the way of sct to numerous
showers on Monday, mainly in the afternoon and evening. Showalter
index numbers/LI values remain modestly/minimally unstable.
Nevertheless, have maintained a slight chc for thunder inland as
the upper cold pool pushes across. Temps once again a touch below
normal. Look for Monday maxima to top out in the upper 60s/around
70 inland, with lower to middle 60s along the southeast coast and
immediate coastal locations.

Evening stabilization should allow for partial clearing inland,
with any areas of showers to diminish quickly after sunset into
Monday night, though pops linger a bit later into the night over
the Eastern Shore. Pops drop off even further after midnight as
the upper low continues to push farther off toward the New
England coast into Tuesday morning. Remaining mild with early
morning lows Tuesday morning in the lower-middle 50s, under a
partly to mostly cloudy sky.

The Tuesday/Wednesday time frame will be characterized by
gradually improving conditions across the region behind the
departing upper low, as high pressure at the surface and aloft
slowly builds across the region in its wake for the mid week
period and beyond. While a gradually clearing sky/dry wx is
anticipated inland (actually mostly sunny by afternoon in the
piedmont), mostly cloudy conditions and some slight to low end
chance pops continue along eastern third of the area. This is in
association with one last upper disturbance rotating through
behind the upper trough. Again, while surface-based instability
looks to be minimal, Showalter numbers indicate some modest,
mainly elevated, instability. Will therefore continue with thunder
mention. Warmer on tuesday with highs in the upper 60s to around
70 coastal locations, low to mid 70s along the coast and mid 70s
to near 80 degrees inland.

Moderating/warming temperatures continues on Wednesday, as 1024+mb
surface high pressure slides offshore, as upper ridging build east.
Deep layered W-SW flow will bring increasing temps and moisture
across the region, though with PW values on the order of 0.50 to
0.75", and with models continuing to trend down with modeled rain
chances, will keep pops out for Wednesday. For the first time in a
couple of weeks, temps trend back up above climo area-wide on
Wednesday, with forecast maxima in the upper 70s to low 80s over
coastal sections along the Eastern Shore, low to mid 80s
southeast VA/NE NC coast, and mid to upper 80s inland.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Bermuda sfc high pressure resides over the wrn Atlantic Ocean
through the long term periods as upper level ridging moves
over the ne CONUS during this time. Although the ridge becomes
more pronounced Fri through Sun, weak waves of energy/moisture
are expected to stream across the wrn fringes of the ridge.
QPF is being depicted each aftn/evening through Sat, however
this appears to be overdone given lack of preferred dynamics
and lack of definitive upper level features to aid lift for
convective development to occur. Held onto slight chance POPs
in far nw counties Thu aftn/evening and then slowly migrate
them ewd Fri/Sat. Current thinking is that the end result will
be high clouds streaming through the region rather than light
rain showers with isolated thunder. Meanwhile, low pressure
begins to develop over the Caribbean on Fri and is expected to
drift twd a location off the FL/GA coast by Sun. Will maintain
slight chance POPs for Sun/Sun night across Central VA due to
pop-up showers developing on the mtns and also in ne NC since
wraparound moisture could make it into this area during this
timeframe.

Overall, high temps should run around 5-7 degrees above normal
Thu-Sat. Highs generally in the mid 80s (mid 70s-low 80s
beaches). Low temps also running about 5 degrees above normal
Thu-Sat nights. Cooler Sun in anticipation of more clouds with
highs in the lower 80s inland and in the mid-upper 70s beaches.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
A little break in the precipitaiton and lower cigs/vsby is ongoing
across much of the area with the exception of the Eastern Shore.
In fact, all sites besides KSBY are seeing VFR conditions as of
2330 UTC. However, the expectation is that soon after sunset,
conditions will deteriorate to IFR conditions overnight as another
round of showers moves into the area from the north. IFR or LIFR
conditions will gradually rise to VFR conditions at all sites
during the day on Monday as drier air moves in from the northwest.
However, this is expected to be a rather slow process as the
responsible upper disturbance will be slow to move east.

OUTLOOK...With all of the moisture from previous day`s rains, if
it clears out Monday night it is concieveable that some fog could
develop especially at KRIC which would have the best chance for
winds becoming light. Otherwise...high pressure builds across the
area for the rest of the week leading to a more late spring/early
summer pattern across the region. Generally, VFR conditions would
be expected unless patchy fog develops overnight.

&&

.MARINE...
Sfc low pressure system that impacted the Mid Atlantic coast
yesterday is now located off the New England coast this aftn with
a frontal boundary extending down along the Southeast coast. A
new sfc low is starting to develop invof the Carolinas and is
expected to slowly track nne to just off the Mid Atlantic coast
late tonight into Mon evening...then into New England on Tue.
Meanwhile, an upper level trough sits over the region through Mon
before gradually sliding off the coast Mon night and tracking
into New England on Tue.

Winds generally n 10-15kt this aftn will become ne 15-20kt for
the Bay/Sound/all coastal waters early Mon morning. Expect gusts
to around 25kt coastal waters and mouth of the Bay during the
morning. Seas currently 3-4ft srn waters/4-6ft nrn waters. Seas
become 4-5ft all coastal waters by late this evening...build to
5-6ft Mon morning...then subside to 4-5ft Mon aftn. For srn Ches
Bay, 2-3ft waves will build to 3-4ft Mon morning and then subside
to 3ft in the aftn. For nrn Ches Bay, waves will average 2-3ft.
SCA flags in effect for Sound, all Bay zones, and all coastal
waters through various end times on Mon. Please refer to the
Marine Weather Message (WBCMWWAKQ) for specific details.

Wind speeds diminish Mon aftn as tightened pressure gradient
shifts ewd beyond 20nm. A secondary increase in wly winds may
be possible late Mon night into Tue morning for the mouth of
the Bay and coastal waters south of Cape Charles Light as sfc
high pressure starts to build into the region from the west,
however speeds of 10-15kt should keep the aforementioned areas
(and Currituck Sound) out of SCA flags attm. Conditions finally
quiet down Tue through Fri. Winds will generally be s-sw
aob 15kt. Seas 2-3ft/waves 1-2ft.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...Small Craft Advisory from 4 AM to 1 PM EDT Monday for ANZ632-
     634.
     Small Craft Advisory from 7 AM to 4 PM EDT Monday for ANZ633.
     Small Craft Advisory from 4 AM to 10 AM EDT Monday for ANZ630-
     631.
     Small Craft Advisory until 1 AM EDT Tuesday for ANZ650-652-654.
     Small Craft Advisory until 8 PM EDT Monday for ANZ656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...AJZ/MAM
LONG TERM...BMD
AVIATION...MRD
MARINE...BMD



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