Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 181906
Area Forecast Discussion
National Weather Service Wakefield VA
206 PM EST Sat Feb 18 2017
High pressure moves off the southeast coast today. A weak area of
low pressure moves across the Carolinas tonight with high pressure
returning Sunday. A weak backdoor front pushes across the Eastern
Shore Sunday night. High pressure builds well north of the region
early next week.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The latest analysis depicts a split flow pattern across the
Central and Ern Conus, with a srn stream trough over the Lower
Mississippi Valley upstream of a ridge over the Mid-Atlantic.
The nrn stream has shifted well to the N with a trough near
James Bay. Upper level moisture increases across the region
today ahead of the trough to the WSW. The sky will be partly to
mostly sunny this morning and then become partly to mostly
cloudy (mainly W) during the afternoon due to a thickening
cloud deck aoa 15K ft. Despite the increasing cloudiness, highs
will reach spring like levels with 70-73 west of the Ches Bay,
mid to upr 60s eastern shore, near 60 at the beaches.
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
The upper system dampens as it lifts into the central Appalachians
tonight with the energy shifting to a low off the Carolina coast.
Little if any moisture noted in the latest guidance but can`t rule
out some light rain across the piedmont after 03Z due to the
weakening trof and along the NC zones that border the Albemarle
sound after 06Z closer to the actual track of the low. Otw, mostly
cloudy and mild. Lows 45-50.
The low pushes farther offshore Sunday morning with high pressure
establishing itself across the region Sunday afternoon. WNW winds
behind the low will be light. H85 temps drop a bit, but the
combination of increasing amounts of sunshine along with a light
downsloping wind results in another day with well above normal
temps. Highs upr 60s-lwr 70s west of the Ches Bay, except mid 60s
eastern shore and beach areas.
1030 mb high builds into the Ern Great Lakes Sunday night and pushes
a weak backdoor boundary through the Ern Shore. This high produces
an onshore flow along the coast, resulting in cooler (but still
above normal) temperatures along the coast, while the Piedmont
remains mild. Lows Sunday night in the 40s. Highs Monday range from
low-mid 50s near the water to between 65-70 across the piedmont.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
High pressure will settle over the region Mon night through Tue and
then slide off the Mid Atlantic Coast Tue night into Wed. After
that, the area sits right smack in the middle of split flow with
active systems passing well north and well south...and primarily
westerly flow aloft. This is not a good set-up for active weather
within the long term forecast periods. 12Z GFS now trying to depict
one long, elongated trough passing through the region on Wed and
bringing precip to the area. This is a new solution and does not
seem to hold much merit to what should happen in reality. The 12Z
ECMWF is also trying to bring weakening shortwave energy and light
precip across the area as well. Leaned more towards a WPC solution
regarding POPs and then dropped everything by 5 percent. This ends
up keeping a slight chance for rain showers late Tue night into
Wed. Will see how this pans out against new 18/1200Z data.
Otherwise, expect a generally dry forecast with temperatures running
anywhere from 10-20 degrees above seasonal normals.
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
-- Changed Discussion --High pressure slides off the coast today as weakening low
pressure approaches from the WSW. Clouds will increase later
today into tonight, with a period of 8-10kft cigs overnight, and
sct clouds could linger into Sunday morning. A light SW wind
today and tonight will become NW Sunday. The forcing associated
with this system will shift offshore, with rain chances less
than 15%. High pressure returns later Sunday, which will allow
for dry and VFR conditions to continue into early next week. A
weak cold front will cross the region Tuesday night into
Wednesday with only a minimal chance of light rain.
-- End Changed Discussion --
Sub-SCA conditions this weekend into next week. Weak high pres
prevails over the wtrs today with S/SW winds up to ~10 kt over the
Bay/rivers/Sound and 10-15 kt over cstl wtrs with 2-3 ft seas.
Similar conditions tngt as a weak wave of low pres develops off the
Carolina and SE coasts. Winds then shift to NWly Sun mainly aob 10
kt with seas still 2-3 ft, and 1-2 ft waves over the Bay. High pres
builds in from the west Sun night, settling over the wtrs Mon and
Tue allowing for benign marine conditions to continue.
Very warm this weekend, currently not expecting to set record highs
but it may be close so for reference the record highs are listed below:
* Site Sat 2/18 Sun 2/19
* RIC: 77 (2011) 78 (1961)
* ORF: 77 (1937) 73 (1907)
* SBY: 75 (1976) 72 (1961)
* ECG: 80 (1976) 77 (1939)