Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 241707
Area Forecast Discussion
National Weather Service Wakefield VA
107 PM EDT SUN JUL 24 2016
High pressure prevails over the region through Tuesday. A weak cold
front drops into the region Tuesday night into Wednesday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The current surface analysis continues to depict high pressure
across the Southeast US with a trough extending along a PHL-ROA-
AVL line. The challenge for today remains whether or not dewpoints
drop a few degrees during the afternoon. 850mb temperatures remain
in the 20-22C range today (+2 st dev). Given strong solar
insolation this should easily support highs in the mid/upper 90s
across the area with the exception of upper 80s/low 90s at the
immediate coast. Resultant heat index values will be very
sensitive to dewpoints given temperatures well into the 90s.
Dewpoints are expected to drop to around 70 over the nw Piedmont
counties in vicinity of the surface trough, and over the Lower MD
Ern Shore in closer proximity to a retreating weak front.
Elsewhere, dewpoints should remain in the low/mid 70s resulting in
heat indices of 105 to 109. The spatial coverage of the heat
advisory remains representative of the latest data. Forecast
soundings show that the airmass remains capped again today
limiting the potential for convection. High-res data suggests at
the potential for an isolated tstm along the wrn shore of the
Chesapeake Bay, but confidence and possible coverage is not enough
to raise PoPs above 14%.
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
Warm and humid tonight with lows in the mid to upr 70s. Hottest day
of this stretch appears to be on Mon with highs in the mid-upr 90s
again, except upr 80s-lwr 90s at the beaches. Not out of the qstn
to see an AWOS record 100. Dew pt temps progged to be in the low-
mid 70s fa wide. This would agrue for most if not the entire fa in
a heat advsry. Only chc for isltd tstms is over the nwrn zones,
all depending on how far east any tstm off the mts can move.
The upper ridge begins to slowly break down Mon night into Tues as a
frontal boundary slowly approaches from the west. Remaining warm and
humid Mon night with evening convection limited to the northern most
zones. Lows in the low-mid 70s. Continued hot Tuesday with highs in
the mid 90s. Dew pts remain in the low-mid 70s resulting in heat index
values aoa 105 most areas (heat advsry range). There is a 20-40% chc
of afternoon tstms west of the Ches Bay after 18Z.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Stacked high pressure over the Southeast Coast allows zonal/westerly
flow aloft to settle across the region Tuesday night through the
week. A series of wx disturbances will pass across the region and
keep a chance for thunderstorms in the forecast each aftn/evening.
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...making strong gusty winds and locally heavy rainfall
the anticipated impacts from thunderstorms. Combine the humidity
with temperatures remaining in the low 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 /17Z SUNDAY THROUGH THURSDAY/...
High pressure off the SE U.S. coast continues to be the dominat
weather feature through at least Monday. VFR conditions and light
winds continue through the 18z TAF period, and beyond, over all
terminals. Expect winds to avg out of the s/sw this aftn at 5-8
kt, except on the DELMARVA, where a weak frontal boundary has
shifted winds to the E/ESE.
OUTLOOK...Another mainly dry day is expected Monday. A cold front
drops into the area Tuesday/Wednesday bringing isolated-scattered
showers/tstms both days...primarily during the afternoon/evening
hours. Brief reductions in VSBYS and CIGS to MVFR/IFR levels are
possible with the storms.
Benign marine conditions expected this week with no headlines
necessary. Expect a fairly stagnant wx pattern today into Mon with
hi pressure centered off the se coast and weak trofs of lo
pressure over the Mid Atlc. Winds will avg 10-15 kt out of the
s/sw thru this period 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 Monday night ahead of the
next cold front. This front drops into the area late Tue/Tue
night, and remains in the vicinity thru the end of the week.
While its certainly going to be hot today thru Mon, climatologically
this is the hottest time of the year with several heat waves having
occurred in the past that have been far more intense than what we
will experience. Record highs are unlikely to be set Sun/Mon, and in most
cases, don`t expect that they will even challenged within 5 deg F.
* RECORD HIGHS:
Records Sun (7/24) Mon (7/25)
* RIC: 105 (2010) 105 (2010)
* ORF: 105 (2010) 105 (2010)
* SBY: 101 (2010) 100 (2010)
* ECG: 97 (2012) 99 (1949)
NC...Heat Advisory until 8 PM EDT this evening for NCZ012>017-
VA...Heat Advisory until 8 PM EDT this evening for VAZ065>068-