Area Forecast Discussion
Issued by NWS Wakefield, VA

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FXUS61 KAKQ 251457
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
1057 AM EDT MON JUL 25 2016

.SYNOPSIS...
High pressure prevails over the region through Tuesday. A weak front
drops into the region Tuesday night...then lingers across the region
through most of the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update as of 1045 AM EDT...
Have added the MD Beaches, including Ocean City, to the Heat
Advisory as latest readings show heat indices nearing 105 late
this morning. A 10-12 mph SW wind will deter the sea breeze at the
MD beaches for a couple of hours until some relief occurs.
Otherwise, no significant changes are necessary to the ongoing
forecast.

Previous Discussion...
Heat wave to peak today as the broad upper ridge dampens over the
Ohio Valley but remains firmly entrenched over the wrn Atlantic.
1000-500mb thickness values rise to around 5820m over the Piedmont
and 850mb temperatures average around 22-23C across the region.
This easily supports highs in the upper 90s to near 100 across the
area with even lwr 90s at the immediate coast. Dewpoints remain in
the low/mid 70s across most of the area through peak heating
hours. This results in widespread heat indices between 105 to 109
(highest across inland portions of SE VA and NE NC). Thus...heat
advisory remains in effect for the entire area.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
Airmass remains capped so no convection expected thru 22Z. Isltd
tstms psbl across the nrn most zones this evening due to any mt
convection that may drift east. OTW...another warm and humid night.
Lows in the mid-upr 70s.

Tuesday starts off dry as the high prs continues to dominate.
Remaining hot as 1000-500mb thickness values only drop to around
5780-5800m and 850mb temperatures drop only to 20-21C. This supports
highs in the mid 90s. Dewpoints remain in the low/mid 70s with heat
indices arnd 105 with heat advisory criteria likely reached again
over the southern two thirds of the fa before any convection
develops. The ridge breaks down enough Tuesday afternoon into
Tuesday evening to allow a weak front to drop into the area and
shortwave energy to cross the mountains. Models a bit faster in
developing tstms across the fa by 18Z. Will carry a 30-40% chc of
showers/tstms west of the Ches Bay with slght chc pops to the ern
shore. No severe expected but gusty winds and locally hvy downpours
possible in any tstm.

Tstm chcs continue Tues nite as the boundary sags south across the
fa. Best support for tstms shifts towards the coast after midnite.
Still warm and humid with lows in the mid/upper 70s.

Westerly flow aloft will allow for the boundary to stall over the
region Wednesday. Enough moisture and support for chc pops across
the area.  Highest chc (30-40%) will be from central/s-central VA to
se VA and ne NC. Highs reach the low 90s under a partly sunny sky.
Dewpoints will be highest across se VA/ne NC with heat indices
approaching 105 once again.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Stacked high pressure over the Southeast Coast allows zonal/westerly
flow aloft to settle across the region through the rest of the
week. A series of weather disturbances will pass across the region
as a thermal boundary/lee trough sets up over the area. This will
provide a focus for thunderstorm development and keep a chance for
storms in the forecast each aftn/evening. Areal coverage fluctuates
with each passing model run and will therefore maintain more
broadbrushed POP grids. Pwats around 2.00-2.25 inches and dewpoints
in the low-mid 70s will result in muggy conditions with ample
moisture present across the area. Factor in weak steering flow
aloft and the anticipated impacts from any thunderstorms will be
locally heavy rainfall and strong gusty winds. Combine the humidity
with temperatures remaining in the lower 90s, and heat indices
will continue to run around 100-104 degrees with a few pockets in
far SE VA/NE NC reaching 105-106 degrees for an hour or two each
aftn. Lows generally in the low-mid 70s inland and mid-upper 70s
beaches.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
12Z taf period starts off with vfr conditions and mostly light
winds over the terminals. Expect winds to avg out of the s/sw
this aftn at 8-12 kt with mainly just some passing hi clouds. A
few higher gusts are possible. There is a chance of shras/tstms at
ksby tonight but the chance is too low attm the warrant mention in
the taf.

OUTLOOK...A cold front drops into the area late Tuesday and then
stalls over northern portions of the area. A daily chance for
afternoon and evening shras/tstms can be expected Tuesday through
Friday.

&&

.MARINE...
Benign marine conditions expected this week with no headlines
necessary. Fairly stagnant wx pattern continues today with hi
pressure centered off the se coast and a weak trof of lo pressure
over the Mid Atlc. Winds will avg 10-15 kt out of the s/sw with
1-2 ft waves over the Bay and 2-3 ft seas over Cstl Wtrs. There
may be a surge in winds to 15 kt Bay/Sound and 15-20 kt coastal
waters tonight ahead of the next cold front, with seas up to 4 ft
over northern coastal waters. This front drops into the area late
Tue/Tue night, and remains in the vicinity thru the end of the
week. There will be a chance of shras/tstms each aftn/eveng.

&&

.CLIMATE...
While its certainly going to be hot thru Tue, climatologically
this is the hottest time of the year with several heat waves having
occurred in the past that have been more intense than what we
will experience. No records were set Sunday. The only record high
in jeopardy is today at ecg.

* RECORD HIGHS:

 Records Mon (7/25)   Tue (7/26)

* RIC:   105 (2010)   100 (1940)
* ORF:   105 (2010)   100 (1940)
* SBY:   100 (2010)   102 (1940)
* ECG:    97 (1949)    97 (1949)

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...Heat Advisory until 8 PM EDT this evening for MDZ021>025.
NC...Heat Advisory until 8 PM EDT this evening for NCZ012>017-
     030>032-102.
VA...Heat Advisory until 8 PM EDT this evening for VAZ048-060>062-
     064>069-075>090-092-093-095>100-509>525.
MARINE...None.

&&

$$
SYNOPSIS...MPR
NEAR TERM...JDM/MPR
SHORT TERM...AJZ/MPR
LONG TERM...BMD
AVIATION...MAS
MARINE...MAS
CLIMATE...


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