Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
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FXUS61 KAKQ 282237
Area Forecast Discussion
National Weather Service Wakefield VA
537 PM EST Mon Nov 28 2016
High pressure becomes shifts off the coast tonight resulting in
an increasing southerly flow Tuesday and Wednesday. A complex
weather system approaches the region from the west for
midweek...bringing an increased chance of rain to the region. A
cold front will push through the area early Thursday.
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Surface high pressure has shifted off the coast resulting in a
gradually increasing southerly flow. High level cirrus streaming
across the area ahead of the next system has a few thinning areas,
but the thinning occurred a little too late to realize peak
heating for the day keeping highs in the low to mid 50s. Mid
level clouds will start to spread in from the SW early this
evening rapidly overspreading much of the forecast area overnight
as the low level jet increases. models suggest a low level jet of
40 to 50 kt setting up between 06z and 12z. This along with a weak
upper wave will bring some light rain and drizzle to portions of
the forecast area late tonight, but qpf overnight will be low.
Temperatures will fall into the upper 40s (some mid 40s well
inland possible) this evening, but then warm overnight as the low
level jet sets up and surface southerly flow increases.
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
The primary upper trough will continue to sharpen and dig south over
the Plains Tue and Wed. Models are in continued agreement
suggesting showers tuesday morning into the afternoon mainly
along and north of I-64 (including MD) as the first weak upper
wave moves through. Even in areas (across southeast VA and
northeast NC) where there is less shower activity skies will
remain mostly cloudy. There will be a break/lull in the overall
shower activity Tue night and Wed morning before the main push
with the upper trough and attending cold front come through late
Wed. POPS increase once again Wed afternoon as forcing increases
ahead of the front with likely to categorical POPS expected
across the entire region Wed afternoon into Wed night as the
system pushes from west to east. Given the warm/moist airmass in
place and forcing there is a risk for a few thunderstorms and SPC
has the area in a Marginal Risk for severe storms. Total (average)
QPF Tue-Wed 0.50-0.75" NW to 0.20-0.35" SE.Everything pushes off
the coast Thursday morning as much cooler air rushes in behind the
Strong pre-frontal WAA will make for a couple of very mild
to warm days Tue and Wed. Highs Tue in the upper 60s well inland
to lower 70s SE VA- NE NC. Highs Wed in the near 70 well inland
mid 70s in SE VA- NE NC.
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The extended period is expected to begin with
cool high pressure gradually building across the Southeast Conus.
This will result in dry conditions, with temperatures slightly below
seasonal averages, but within -1 st dev. Sky cover is expected to be
mostly clear, however, increasing high clouds are possible Saturday.
Forecast lows Friday morning range from the mid 30s to around 40,
followed by highs Friday in the low/mid 50s. Slightly cooler Friday
night and Saturday with lows ranging from the low 30s inland to the
mid/upper 30s along the coast, and highs around 50. There is the
potential for highs to remain in the 40s Saturday if thicker high
clouds arrive earlier. GFS/ECMWF diverge Saturday night through
Sunday night, with the GFS depicting a progressive nrn stream wave
tracking across the region, while the ECMWF shows a phased system
lifting ne through the Ohio Valley. At this time forecast PoPs are
~30%, which is slightly above climo. Model differences continue into
Monday, but the consensus is for a drier pattern.
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR to start off the 18Z taf period with sfc hi pressure sliding
offshore and high clouds streaming in from the west. A low
pressure systm also approaches from the west tonight, and
southerly winds increase tonight into Tue as cigs drop as well.
Included shras in the last six hours of the TAF period at
KRIC/KSBY where confidence is the highest, but rain is psbl at all
the TAF sites Tue as are MVFR cigs. Periodic sub-VFR conditions
are expected through midweek with another (better) chance of rain
High pressure slides offshore tonight ahead of a trough
pushing through the Ohio Valley. Southerly flow is expected to
increase later tonight into Tuesday with wind speeds reaching 15-
25kt, with gusts up to 30 kt over the ocean. Waves in the Bay build
to 3-4ft, with 5-7ft (highest n) in the ocean. The trough lifts newd
through New England Tuesday night with the wind becoming sw and
diminishing to 10-15kt. Waves in the Bay subside to 2-3ft. However,
seas likely remain 4-6ft. SCAs for the Bay/ocean/sound remain as
is, and an SCA flag has been raised for the rivers from 12z-21z.
A cold front is expected to push through the Ohio Valley Wednesday
and then push off the Mid-Atlantic Coast late Wednesday night. The
wind should shift bay to south Wednesday into Wednesday evening and
increase to 15-25kt. It is likely that another round of SCAs will be
necessary for the Bay/Sound/rivers, while seas may not drop below
5ft (especially n) between the two events. The wind becomes westerly
at 10-15kt (minimal CAA) behind the front late Wednesday night into
Thursday as the front shifts offshore. A nw wind of 10-15kt should
prevail Friday into Saturday as high pressure builds across the
Southeast Conus. Seas subside from 3-4ft to 2-3ft, with ~2ft waves
in the Bay.
MARINE...Small Craft Advisory from 7 AM to 4 PM EST Tuesday for
Small Craft Advisory from 4 AM to 7 PM EST Tuesday for
Small Craft Advisory from 7 AM Tuesday to 6 AM EST Wednesday