Area Forecast Discussion
Issued by NWS Wakefield, VA

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085
FXUS61 KAKQ 190840
AFDAKQ

Area Forecast Discussion
National Weather Service Wakefield VA
340 AM EST Mon Feb 19 2018

.SYNOPSIS...
High pressure slides offshore today, allowing for a return of
moisture. A warm front lifts through the area tonight. High
pressure becomes anchored off the southeast coast Tuesday and
Wednesday bringing a return to well above normal temperatures.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Sfc high pressure is situated off the Mid-Atlantic coast this
morning allowing for light E-SE flow to bring moisture back into
the local area. This moisture is poised to move into SW/W
portions of the FA by 9-10z in the form of light rain, and so
have likely PoPs (60-70%) across the Piedmont thru 12z, and
chance PoPs (30-50%) as far east as the I-95 corridor.

With the sfc high drifting east and well off the mid-Atlc/New
England coast today, overrunning moisture pushes across the
local area with mainly cloudy skies and a light E/SE flow. Best
forcing remains off to our NW, however, so not necessarily
looking at a lot of QPF. Still looks like a 6-hr period between
12z-18z with enough lift to support likely PoPs over much of the
area. Will carry 40-70% PoPs most areas for now before 18z,
then chc PoPs in the afternoon 30-40%, except slight chc PoPs
15-20% west of I-95. Not a true CAD setup, but a lot of clouds
and shallow mixing will keep it cool for much of the day. Late
day highs will avg 50-55F, except warmest SE with highs reaching
the low 60s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
Increasing SW flow tonight as upper ridge axis begins to
amplify/build off the SE coast. Models indicate some continued
light QPF amounts overnight, but there is little forcing for
precipitation so will genly keep PoPs capped at less than 20%.
Milder with little drop in temperatures due to the SW flow, lows
ranging from the upper 40s well inland to the lower-mid 50s SE.
The local area will be firmly in the warm sector on Tue, with
strong upper ridge centered over the Gulf Stream off the SE
coast. However, GFS/NAM continue to depict a lot of low level
moisture across the area and fairly shallow mixing per Bufkit
soundings through the entire day. This is probably overdone and
suspect the SW low level flow and 850mb temperatures rising to
+10 to +12 C will be sufficient to scour out the low level
clouds by late morning and allow for a partly sunny aftn. Highs
expected into the 70s except for locally cooler conditions at
the immediate coast. Very warm Tue night into Wed with continued
SW flow. Approaching sfc cold front to remain west of the
Appalachians through the day which will limit chances for rain.
The GFS/ECMWF/NAM do show an area of enhanced moisture pushing
into the Piedmont during the late morning/aftn but this will
likely just translate into a little more cloud cover. Partly
sunny overall with highs mainly ranging from the mid to upper
70s except for locally cooler conditions at the immediate coast.
If it turns out mostly sunny with deeper mixing than
anticipated, some locales could rise into the lower 80s. See
record highs below.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Region will overall be dominated by mid/upper level ridging
during the extended period. Shortwave trof will temporarily
break down the ridge Wednesday night/Thursday, allowing  a cold
front to drop through the region from the N/NW on Thursday.
High pressure will build to the north of the region behind the
front cold front, with temps dropping back closer to normal for
Friday. Front potentially moves back north of the region by
Saturday, allowing for another surge of warmer air to move into
the region for Saturday/Saturday night. GFS/ECMWF are in some
disagreement with how far the warm front gets, as well as how
quickly the next cold front moves into/through the region. ECMWF
less bullish in moving warm front north, which causes the
Saturday/Sunday period to be more unsettled, and potentially
cooler than GFS would suggest. At this point, have used the
blended model solution, which sides toward a warmer day 6/7
period.

Outside of the model inconsistency in the day 6/7 period, the
chances for rain appear most likely on Thursday with cold
frontal passage, and possible Friday into friday night, as front
tries to lift back northward. Temperature-wise, another warm
day on Thursday ahead of the cold front, with high temps in the
60s/low 70s. Cooler Friday with highs in the 50s to around 60,
then potentially warmer on Saturday, with most areas in the 60s.
If ECMWF is correct, warmer temps will be restricted to the
southern half or so of the CWA. Sunday also remains uncertain
with regard to temperatures, but they should still be above
normal. Overnight lows in the 40s to around 50 Thursday and
Friday night, then in the 50s Saturday night.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR conditions expected early this morning as clouds begin to
return and thicken. Deteriorating conditions begin from about
09-12Z SW of KRIC, then persisting through the day as
lowering/thickening CIGS return from the SW with a decent
chance for rain from 12-18Z at area terminals. Sfc winds will be
mostly light SE-S through Monday night less than 10 kt.

Outlook...Low stratus/IFR/LIFR expected into Mon night and Tue
morning (could also be some fog). Expect VFR/warm SSW flow to
prevail Tue after the early am clouds scour out. A cold front
approaches from the NW on Wednesday but expect VFR conditions to
prevail.

&&

.MARINE...
Latest Obs/Buoy reports reflect E-SE flow ~10kt this morning. Sfc
high pressure in place over the waters is allowing for light winds
early this morning, with winds to veer around to the SSE from late
morning through this afternoon, then SSW tonight as high moves
offshore and Sfc warm front lifts north of the region (accompanied
by sct/numerous showers today.

Sub-SCA SSW flow persists tonight through midweek, with waves
generally 1-2 feet on the Bay, and 2-3 feet on the ocean. With winds
remaining below SCA criteria, will need to monitor for marine fog,
especially Tuesday night and Wednesday, as dew points increase into
the 50s.

Back door cold front drops across the region on Thursday, turning
winds to the N/NE over at least northern waters during the day on
Thursday. Deterministic guidance is still split over how far south
the boundary slips before washing out or weakening/lifting back
north on Friday. In either event, weak CAA behind the front likely
will keep winds below SCA criteria through much, if not all of this
period. NWPS indicating potential for some increasing wind wave by
Wed night/early Thursday, which could make for some choppy seas
during this period in NE Flow before winds gradually veer back to
the S by later Friday as boundary lifts back north.

&&

.CLIMATE...
Another round of record highs will possibly be challenged Tue
2/20 and Wed 2/21:

* Record highs:

* Date: Tue 2/20   Wed 2/21

* RIC:  77 (1930)  75 (1930)
* ORF:  77 (1991)  79 (2014)
* SBY:  75 (1930)  75 (1943)
* ECG:  78 (1991)  77 (2014)

&&

.EQUIPMENT...
KAKQ radar will be down UFN.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...None.
NC...None.
VA...None.
MARINE...None.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM/LKB
LONG TERM...WRS
AVIATION...JDM
MARINE...MAM
CLIMATE...AKQ
EQUIPMENT...AKQ



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