Area Forecast Discussion
Issued by NWS Wakefield, VA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 212056
Area Forecast Discussion
National Weather Service Wakefield VA
456 PM EDT WED SEP 21 2016
A frontal boundary remains stalled along or just off the Southeast
or Mid Atlantic coast into Friday morning, with low pressure
lingering near the Southeast or Mid Atlantic coast tonight into
Friday morning. High pressure builds over the local area Friday
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Late this aftn, remnant lo pres that was tropical cyclone Julia
was cntrd ovr ern SC. This lo pres area continues to pull bands of
showers and isolated tstms into the srn two thirds of the CWA,
with moderate to heavy showers affecting much of the srn half of
the region. Due to continued areal flooding going on acrs most of
SE VA and NE NC, and additional rainfall between .50 inch and 2
inches possible in these areas thru this evening, have extended or
expanded the Flash Flood Watch until midngt. Coverage and
intensity of the pcpn will decrease overnight, and Pops will
decrease rapidly as you go N of a Farmville to Petersburg to
Wallops Island line. Lows tngt will range fm the mid 60s to lower
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
-- Changed Discussion --A frontal boundary and lingering lo pres near the SE or Mid Altc
coast, will continue to result in at least hi chc pops (40-50%)
acrs the Srn/SE portions of the region Thu into Thu evening.
The combination of nrn stream energy and the upr lo/associated
upr trough weakening, will finally result in Pops shifting offshr
later Fri/Fri evening. Surface hi pres will bld over the region
Fri evening into Sat morning. A backdoor front will then drops
acrs the area during Sat. Expecting dry conditions Fri evening
thru Sat. Highs in the mid 70s to lower 80s Thu, and in the upr
70s to mid 80s Fri and Sat. Lows in the 60s to arnd 70 Thu ngt,
and in the mid 60s to near 70 Fri ngt.
-- End Changed Discussion --
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A trough digs over the Northeast US Saturday night into Sunday as
an upper level ridge builds over the Mississippi Valley. That
ridge then slowly amplifies and pushes eastward Mon-Wed. Models
have trended weaker with respect to pushing the associated cold
front completely through the area on Sunday. 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 will average in the 70s with lows in
the upper 50s to mid 60s.
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
A stalled frontal boundary remains near the coast this
afternoon with weak low pressure continuing to slowly move across
eastern NC. Weak high pressure is currently situated to the north of
the area. Showers continue to move across portions of SE Virginia
and NE North Carolina this afternoon with a slight decreasing trend
in coverage/intensity. Showers have also developed across central
Virginia and continue to propagate west of RIC.
Similar to the past few nights, tricky forecast is in store for IFR
versus MVFR. Expecting stratus to develop in this moist airmass,
thus have IFR conditions in the forecast for RIC/SBY/ECG with cloud
decks hovering between 500-600 feet at these locations later
tonight. Also cannot rule out the chance for showers near the coast,
especially during the first half of the overnight period. Reflected
this in the TAF by leaving showers in the forecast through 00Z for
ORF/PHF/ECG. Am expecting a gradual improvement in cigs to MVFR
conditions by morning with cloud decks rising above 1000 feet across
the region after 12Z. Winds across the area are generally onshore
around 10 knots. Winds are still expected to gust up to 20 knots
along the coast.
Outlook: Gradual improving conditions are expected Thursday into
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.
SCA headlines are in effect for all coastal waters (through Thu night), for
the lower/mid Bay (through tonight/Thu morning, and lower James/Currituck
Sound through this evening.
The wind slowly diminishes late tonight/Thursday, but seas remain 4-
6 ft for Ocean waters. The latest data suggests low pressure emerges back over the
ocean Thursday night into Friday, which suggests a modest 10-15kt
nne wind continues. This will allow seas to remain 3-5ft, with 2-3ft
waves in the mouth of the Bay. A cold front approaching from the N
Friday night and pushing into the area Saturday is now looking to stall over the
Carolinas by Sunday. Marginal SCA conditions are possible but appear less likely
now that the cool surge behind the front may stay mainly N of the
As of 20Z, 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 major sites falling short of Minor Flood
thresholds by around 0.5 ft. Will maintain the Coastal Flood Advisory
for the mid/upper James River zones through 7 pm this evening but have
allowed the remainder of advisories to expire. Additional tidal
flooding does not look likely for Thu, with 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 which could lead to some marginal tidal flooding by that time.
A beach hazard statement will continue today for a high threat of
rip currents and dangerous shorebreak across the southern beaches.
NC...Flash Flood Watch until midnight EDT tonight for NCZ012>014-
VA...Coastal Flood Advisory until 7 PM EDT this evening for VAZ089-
Flash Flood Watch until midnight EDT tonight for VAZ092-093-
MARINE...Small Craft Advisory until 4 AM EDT Friday for ANZ652-654.
Small Craft Advisory until midnight EDT Thursday night for
Small Craft Advisory from 4 AM Thursday to 4 AM EDT Friday for
Small Craft Advisory until 10 AM EDT Thursday for ANZ631-632.
Small Craft Advisory until 10 PM EDT this evening for ANZ633-