Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 290326
Area Forecast Discussion
National Weather Service Wakefield VA
1026 PM EST Mon Nov 28 2016
-- Changed Discussion --High pressure centers offshore tonight. 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.
-- End Changed Discussion --
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --Based on latest radar trends and hi-res guidance, have opted to
pull back on POPs a few hours late tonight. 29/00Z KRNK and KLWX
RAOBs still indicate relatively dry air below 600-650mb as high
pressure remains centered off the Mid-Atlantic coast. Blended
total precipitable water product indicates the best moisture still
remains west of the mountains this evening. Expect moisture to
increase across the Piedmont late tonight as the upper ridge axis
pushes offshore and a warm front lifts over the region. A low
level jet will begin to advect better moisture into the region as
dewpoints quickly warm from the 30`s to low 40`s into the low to
mid 50`s by daybreak. NAM12/RAP 295-300K surfaces indicate the
best isentropic lift along the lifting warm front will remain over
the Piedmont into central Virginia. Have maintain the highest
POP`s over that region, but have pushed the best POPs back until
after 4 AM. Rainfall amounts less than one half inch expected. Sky
becomes mostly cloudy to cloudy late tonight. Low temperatures are
occurring, or have already occurred, at many locations this
evening. Temperatures are forecast to warm into the mid 50`s by
daybreak. Southerly winds increase to 10-15 mph.
-- End Changed Discussion --
.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 /03Z TUESDAY THROUGH SATURDAY/...
Surface high pressure has centered just offshore early this
evening, with VFR conditions prevailing across the local area.
Scattered to broken mid level clouds with decks 4-6k feet AGL
persist over the Piedmont, with generally high clouds elsewhere.
Surface winds are generally southeasterly at or below 10 knots.
High pressure slides farther offshore tonight as a storm system
approaches from the west. An increasing low level jet tonight will
result in strong winds 1-2k feet AGL late tonight across the
Piedmont into central Virginia. Have included LLWS in the RIC TAF
late tonight into early Tuesday morning. Expect ceilings to drop
to MVFR late tonight over the Piedmont into central Virginia, but
do not anticipate IFR conditions at the TAF sites (like the
MET/NAM indicates) due to mixing. Light showers become likely KRIC
and KSBY early Tuesday morning.
Light showers expected to persist through Tuesday morning, with
the best chances KRIC northward. Lower confidence in the
southeast. MVFR ceilings anticipated to persist, with MVFR
visibilities at times. Showers taper southeast to northwest during
the afternoon. Breezy, with southerly gusts of 20 knots inland and
25 to 30 knots near the coast. 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