Area Forecast Discussion
Issued by NWS Wakefield, VA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 221120
Area Forecast Discussion
National Weather Service Wakefield VA
720 AM EDT THU SEP 22 2016
Low pressure along with a weak frontal boundary will remain stalled
along or just off the Southeast coast into Friday morning. High
pressure builds over the local area later Friday into Saturday.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Surface low pressure is along the SC coast this morning with a
stationary frontal boundary situated along the NC/SC coasts.
Meanwhile, sfc high pressure covers the Northeast. The coastal
features will remain nearly stationary today while high pressure
pushes east to the New England coast. The good news is that the
heaviest rain that we`ve been dealing with the past few days is
done. Have cancelled all flood watch/warnings. The bad news is
that the rain is not completely finished and additional
intermittent rain/showers will impact mainly the lower 2/3rds of
the FA throughout today. Will continue likely pops through
southside VA thru 9am or so...tapering off to slight chc pops
across far northern portions of the FA and low chance pops across
coastal NE NC. Will then have high chc to low end likely pops
(30-60%) across the lower 2/3rds of the FA for the rest of
today...and mostly dry across the far N/NW as high pressure wins
out. Remaining cloudy/mostly cloudy today with high temperatures
close to normal (upr 70s to low 80s).
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
The combination of nrn stream energy and the coastal low/associated
upr trough weakening, will finally result in pops shifting farther
south beginning tonight but especially Fri/Fri night. Will carry
slight chc to low end chc pops (20-30%) across sern areas only. Surface
high pressure will build over the by region Fri night for dry wx
everywhere. Lows tonight in the 60s to low 70s. Highs Friday from
the upr 70s coast to the low/mid 80s inland. Lows Friday night in
the 60s to low 70s.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --A backdoor cold front drops across the region during Saturday.
Meanwhile, a trough digs over the Northeast US through Sunday as
an upper level ridge builds over the Mississippi Valley. That
ridge then slowly amplifies and pushes east for the first half of
next week. 00z/Thu suit of models have continued to trend weaker
w/the associated cold front completely through the area on
Sunday, with very little rainfall expected coincident with the
frontal passage. Surface high pressure is progged to become
centered over eastern Canada with a piece of the High ridging down
into the northern mid- Atlantic states Sunday night into Tue
(rather than actually building over the local area). While deep
moisture will be pushed south of the local area, this pattern
suggests that the sensible weather will still feature a persistent
easterly low level flow with skies to avg partly to mostly cloudy
Sunday (and perhaps Mon/Tue as well). Have also lingered 20% POPS
for much of the area Sunday, shifting to the Sw zones Sun
night/Mon. Highs range from the mid/upr 70s Eastern Shore to the
low/mid 80s elsewhere Saturday. Highs will average in the 70s with
lows in the upper 50s to mid 60s Sun-Wed.
-- End Changed Discussion --
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
The heaviest of the rain appears to have come to an end this
morning. MVFR cigs continue through the day with some
intermittent rain...except should see some VFR conditions develop
at KRIC/KSBY this afternoon. Winds across the area are generally
onshore around 10-15 knots with occasional gusts.
Outlook: Gradual improving conditions are expected by Friday as
high pressure continues to build just north of the area. VFR
conditions can be expected by Saturday. Another frontal boundary
approaches the area Sunday into Monday.
Latest obs reflect ENE flow across the waters this morning. Pressure
gradient remains compressed between high pressure well north into
New England and weakening low pressure lingers along/just off the SE
coast. Onshore east winds linger in SCA range through the mid
morning for the middle and lower Chesapeake Bay, with sub-SCA 10-
15kt winds gradually drop off from this aftn through tonight as
pressure gradient slackens a bit further. Waves subside to 1-2 ft in
the bay, but linger in 3-4 ft range this aftn in shorter 5-6 second
wind waves through this afternoon.
Winds turn more northerly and pick up a bit by Fri night as weak low
finally nudges offshore. A weak Cold front drops across the waters
late Friday Night into Saturday, stalling just south of the waters
Sat night and Sunday before sliding south into the Carolinas on
Monday. CAA surge behind the front appears minimal...but SCA for
hazardous seas possible over the weekend as longer period swell
begins to mix in Friday night through Sunday.
The Cashie River at Windsor has crested near 14.5 ft (major
flooding begins at 13 ft) this morning and will linger at this
level into the afternoon before slowly subsiding. The Cashie River
is not expected to fall below flood stage until early Friday
As of 22Z, tidal departures avg +0.5 to 1.0 ft over the marine
area, so despite significant flooding from heavy rainfall across
portions of Hampton Roads and northeast NC, actual coastal/tidal
flooding has been minimal from this event with most sites falling
short of Minor Flood thresholds by around 0.5 ft. Have allowed the
Coastal Flood Advisory for the mid/upper James River zones to
expire as High Tide has passed. Additional tidal flooding does
not look likely for Thu but some areas (especially the upper James
River may reach minor flooding again). Feel it is too marginal at
this point for an advisory so will allow next shift to determine
need for a statement or possible an advisory if departures were
to increase more than is currently expected. For now, departures
expected to continue at +0.5 to +1.0 ft through Thu/Fri. One
explanation for the rather low departures may be due to water that
has been able to exit the Bay into the Ocean fairly efficiently
despite the persistent onshore flow. Will continue to monitor
however, as tidal anomalies may build nwd through the Bay by Thu
aftn which could lead to some marginal tidal flooding by that
time farther up into the Bay.
The beach hazard statement has been discontinued, with a moderate
risk for Rips expected for Thu.
MARINE...Small Craft Advisory until midnight EDT tonight for ANZ634-656-
Small Craft Advisory until 10 AM EDT this morning for ANZ631-
Small Craft Advisory until 10 AM EDT Friday for ANZ650-652-654.