Area Forecast Discussion
Issued by NWS Wakefield, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 191734
Area Forecast Discussion
National Weather Service Wakefield VA
134 PM EDT Wed Oct 19 2016
High pressure will remain just offshore through Thursday,
bringing warm and dry conditions to the local area. A cold front
crosses the region on Friday, bringing increased rain chances for
Friday. cooler...near seasonable temperatures return to the
region for the upcoming weekend into early next week.
.NEAR TERM /THROUGH TONIGHT/...
Latest wx analysis continues to feature ~1018mb sfc high pressure
along and offshore of the SE coast, with broad, anomalously strong
upper level ridging also centered over the SE coast, extending
back to the Western Gulf Coast. High pressure will continue to
dominate the weather picture over the local area. SSW flow and
building heights aloft will bring the warmest day of the period
today, with near record highs expected (see the Climate section
below for details). Look for highs into the mid- upper 80s in most
areas, with lwr 80s near the coast...once again under a mostly
Very similar night tonight...Clear and mild with lows again in the
low to mid 60s.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A cold front and associated mid-level trough traverse the TN/OH
Valleys late tonight and Thu. Will maintain a dry forecast attm,
with moisture associated with an offshore passing tropical low
expected to not impact the fa, with showers associated with the
front to the north remaining back into the Blue ridge and up
toward the Mason-Dixon line. Closer to home, expect continued mild/warm
conditions, albeit not quite as warm as heights drop off a bit
into Thu. After early morning lows in the mid 60s, look for highs
Thu in the low-mid 80s. Increasing clouds late Thursday night as
the trough axis digs south, forcing the sfc front east toward the
Mtns into Fri morning. Lows again in the low to mid 60s.
For Friday, deterministic models have come into better agreement
with the handling of the upper trough as it builds east of the
Middle Mississippi River Valley Thursday night through Friday.
GFS is now a bit more progressive than the OP ECMWF, with the
now-slower ECMWF not pulling the associated sfc front through
until Friday evening. Given the converging model solutions, have
split the difference between the two and gone close to an EPS
blend with frontal/PCPN timing on Friday. Expect front to cross
into the western piedmont zones after sunrise Friday morning,
reaching the coast by Friday aftn. Pops have been pushed into
likely range over northern half of the area, tapering back to
30-40% over southern/southeastern tier of the CWA. Pre-frontal
showers will be minimal, given shallow lift and best forcing/moisture
displaced to the west. Thus, will keep forecast dry Thu night for
all but far western tier of counties (and even slight chc there
before sunrise Fri morning). As forcing for ascent quickly shunts
east, pops ramp up Friday morning and afternoon, again with
highest rain chances over the northern/central CWA. QPF forecast
is close to WPC blend, which clusters nicely with 00z/19 GEFS
mean...averaging between one-third and one-half of an inch north
to a tenth or less across NE NC counties.
For temps, high temps tricky for Friday. Have gone closer to
cooler envelope of guidance MAV/MEX in expectation of more in the
way of clouds across the west, with showers developing Fri morning
from W to E. A bit more of an opportunity for some morning peeks
of sun across the eastern tier, and have therefore kept highs
closer (but just below) to the warmer end of guidance out east.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Cold front continues to push well off the coast Fri night as low
pres tracks NE through nrn New England. Mainly slight chc PoPs
will be confined to Fri eve and nrn portions of FA. Dry/cool deep
layered NW Flow Sat-Sun. Gusty WNW winds Sat wane Sat night-Sun.
Flo aloft becomes zonal (briefly) Mon resulting in a slight
warming trend before a secondary push of dry/cool air arrives by
Lows Fri night from the u40s W to m50s at the coast. Highs Sat 60-
65F. Lows Sat night from around 40F NW to near 50F at the
immediate coast. Highs Sun in the l-m60s. Lows Sun night in the u40s-
l50s. Highs Mon 65-70F. Low Mon night from the l40s W to l50s at the
coast. Highs Tue in the l60s.
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --Vfr conditions to start off the 18Z taf period with weak high
pressure over the area and mainly SKC aside from some sct mid/high
clouds over northern areas. This will continue through this eveng.
Overnight, vsbys are expected to drop due to calm/light winds and
small dewpt depressions. IFR fog is psbl but mainly went with MVFR
with it in the latter half of the taf period and confidence not
that high yet. Kept vfr conditions for now at korf where the fog
is less likely. Vfr conds and dry wx then return through the day
Thu as a cold front is located west of the region.
Outlook: The next chance for rain arrives Friday as a cold front
crosses the area. Dry weather returns for the weekend.
-- End Changed Discussion --
A SW surge has developed in response to a weakening cold front
that will pass just north of the area later today. Winds from the
mouth of Ches Bay nwd (including the coastal waters) have increased
to 12-15kt. This surge will persist for a few hours after sunrise
before wind speeds diminish. No SCA flags needed at this time for
srn Ches Bay. For the rest of today through Thu evening, sfc high
pressure will reside near the Mid Atlantic waters. Winds will
remain sly around 10kt during this timeframe. Seas of 2-4ft will
subside to 2-3ft by this evening through Thu night. Waves generally
Meanwhile, a strong upper trough/sfc cold front approaches the Mid
Atlantic Region from the west Thu night and crosses the waters on
Fri...as a coastal low well off the Southeast Coast (possibly
becoming a tropical cyclone) slowly tracks nwd. Although the coastal
low is expected to remain well off of Cape Hatteras on Fri, the
interaction of the coastal low, the passing cold front, and cold
Canadian high pressure building in behind the front will
significantly tighten the sfc pressure gradient beginning Fri aftn
and persisting through at least Sun before winds gradually diminish.
Expect solid SCA conditions (coastal waters/Bay/Sound/mouth of James
River) to develop quickly early Fri evening with NW winds 20-25kt
due to the tight gradient and the presence of strong cold air
advection. Gusts should peak around 30kt through early Sat morning
for Ches Bay; through Sat morning for all coastal waters...and then
through Sun morning for nrn coastal waters (Fenwick Island to Cape
Charles Light). In addition, building seas/swell from the nearby
low should be expected Fri through at least Sun morning. Expect
seas of 4-6ft Fri evening through Sun morning, and waves of 3-4ft
Fri night through late Sat. Another sfc low pressure (similar to
an Alberta Clipper) dives across the nrn waters Mon...allowing
low-end SCA conditions (W-WNW 15-20kt) to develop Mon night into
Tue morning in the post-frontal (yet weaker) cold air advection
environment. Waves build to 3-4ft with seas building again to 3-5ft.
Winds, seas, and waves finally diminish Tue night into mid week as
high pressure returns to the area and cold air advection processes
wane. Winds generally N-NNE aob 15kt with seas subsiding to
Very warm conditions continue today through Thursday with the
possibility of challenging some records today. Current daily
records are listed below:
* Record Highs:
* Wed (10/19) Thu (10/20)
* RIC 87 (1938) 89 (1984)
* ORF 87 (2007) 87 (1984)
* SBY 84 (1938) 84 (1984)
* Record high Mins:
* Wed (10/19) Thu (10/20)
* RIC 73 (2007) 68 (1916)
* ORF 73 (2007) 70 (1916)
* SBY 71 (2007) 68 (1916)