Area Forecast Discussion
Issued by NWS Wakefield, VA
FXUS61 KAKQ 291729
Area Forecast Discussion
National Weather Service Wakefield VA
129 PM EDT FRI JUL 29 2016
High pressure will remain off the Southeast coast today as a weak
frontal boundary lingers to the north of the area. This boundary
slides south this weekend and washes out over the area, before the
next cold front drops into the region early next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update as of 1030 AM EDT... Low clouds still being stubborn to
break up late this morning but clouds bases appear to be lifting
and thinning based on latest obs and satellite trends. Expect
clouds to evolve into a decent CU field this afternoon with not
much in the way of lift to promote shwr/tstm development. Latest
Hi-res guidance not all that impressive with any development this
afternoon so will leave PoPs capped no higher than 20%. Temps
trends are also running cooler due to the cloud cover and made
subtle adjustments to the max temp forecast. Highs from the upr
80s north to the low/mid 90s south. HI values remain below 105
degrees all areas, so need for a heat advisory.
Previous Discussion... Latest surface analysis shows a trough of
low pressure across the fa with a stalled frontal boundary across
pa/nj. This frnt will stay n of the local area today, with a weak
thermal trough remaining over the immediate area. Chance of rain
will be lower than previous days (only 20%) as shortwave energy is
pushing ne of the area already this morng, and little in the way
of upr- level support will remain. Also of note is this will be
the first day in six days without the need for a heat advisory. Hi
temps in the upr 80s to lwr 90s and dewpts in the lo/mid 70s will
yield heat indices in the 100-104 range over extreme se va/ne nc
and 90-100 elsewhere.
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
Any ongoing convection will diminish this eveng/overnight
following the loss of daytime heating. Temps will bottom out in
the lo/mid 70s under a prtly/mstly cloudy sky.
For this weekend...the aforementioned boundary drops towards the
area and weakens. With a weak thermal trough in the vicinity and
upr-level trough over the eastern CONUS, there will be a good
chance (40-50%) of shras/tstms both days, with the precip again
being generally diurnally driven. Expect high temps in the upr 80s
to lwr 90s with low temps ranging through the 70s.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A cold front finally begins to advance on the Mid Atlantic
Sunday night and is expected to cross the area during
Monday...stalling near the Carolinas into mid week. This
will keep a chance for thunderstorms in the forecast mainly
west of Ches Bay in Ern/Cntrl VA and NE NC Sun night
through Tue night. Meanwhile, sfc high pressure settles
over New England which will result in more seasonal temps
in the upper 80s and cooler dewpoints in the upper 60s to
lower 70s...effectively lowering heat indices into the
lower 90s in the extended forecast periods. In addition,
onshore winds develop by Tue morning and are expected to
persist through the rest of the week...thus having a
drying effect on the overall weather and reducing precip
chances below any mention.
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Will carry VCSH across sern TAF sites next few hrs per current
radar trends. Stubborn MVFR SC slow to break up across the area
but do expect all sites to become VFR under a SCT-BKN CU deck.
CU dissipate after sunset with only high level clouds thru the
overnight period. Some patchy fog possible late tonight at SBY.
OUTLOOK...There is a better chance (40-50%) of shras/tstms both
days this weekend with a weak frontal boundary in the vicinity.
Periods of mvfr/ifr conditions are possible in any tstms.
Sub-sca conditions are expected to prevail across the marine area
through the weekend into early next week. A weak cold front will
push through the region this morning producing a wind shift to nw
with speeds generally 10-15kt. The front drops south of the area
tonight resulting in an e wind of 5-10kt. The front lifts back to
the north Saturday into Saturday night with the wind becoming se 10-
15kt. The front settles over the region Sunday into Monday and
pushes off the coast Monday night into Tuesday. Seas average 2-3ft
through the period with 1-2ft waves in the Bay.