Area Forecast Discussion
Issued by NWS Wakefield, VA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 171416
Area Forecast Discussion
National Weather Service Wakefield VA
1016 AM EDT Mon Oct 17 2016
High pressure over the Carolinas will settle just off the
southeast coast through tonight. The High will slide south of the
area through midweek...bringing warm and dry conditions to the
local area through the work week.
.NEAR TERM /THROUGH TONIGHT/...
Latest surface analysis centers ~1020 high pressure over the
Carolinas. A stationary front stretching east to west across the
Great Lakes into the Northeast has induced pressure falls along
the lee side of the Appalachians, resulting in weak lee side
troughing over the Piedmont. Aloft, upper level ridging continues
to build east from to build east from northern Mexico/Texas across
the deep south. A shortwave pushing off the New Jersey coast this
morning has produced some cloudiness along the surface trough
north of the region.
Surface high to the south will continue to push SE to a position
offshore of the Southeast coast by this evening. Return flow will
accelerate ongoing warming trend across the local area. Latest LAV
trends push temperatures into the mid 80`s across the Piedmont
into central Virginia. This matches will with the highest low
level thicknesses. Have bumped temps up a deg or two, with highs
generally in the low to mid 80`s (8-10 degrees above normal).
Cooler along the coast. Weak upper level disturbance drops across
the northeast half of the forecast area this afternoon, which
could help produce some afternoon mid level clouds across the
region. Otherwise, mostly clear conditions expected.
Mainly clear and mild conditions through this evening. Another
night with patchy low clouds/fog possible late. Lows generally in
the low 60s.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Strong/anomalous upper level ridge builds ENE across the deep
south and into the Carolinas through midweek. Meanwhile, Sfc high
pressure builds just offshore of the SE coast. Return (SW) flow/building
heights aloft will promote continued warming trend Tue-Wed, with
high temperatures running 10 to 15 degrees above avg. remaining
dry throughout, w/highs Tue/Wed will avg in the lower to mid 80s
(with GEFS plumes and thickness tools indicating the potential
for some upper 80s out west on Wed). Some record highs could be
challenged (see Climate Section for details). Early morning lows
in the upper 50s to lower-mid 60s Tuesday and Wednesday mornings,
again with some patchy fog/stratus possible each morning.
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Anomalous upper level trough deepens over the central CONUS
Thursday, with an associated cold front locating over the Ohio
Valley. Meanwhile, a weakness under the western Atlantic ridge
progged to lift northward late in the day Thursday, with an
associated surface low location well offshore of the Southeast
coast. A ridge of high pressure will remain over the local area
Thursday, with 850mb temps still around +14-16C (+1 standard
deviation). The result will be another day of well above normal
temperatures, with highs generally in the upper 70`s to low 80`s.
While spatial and timing differences remain with respect to the cold
front and offshore low pressure system, expect the front to cross
the central Appalachians late Thursday night, dropping into the
local area Friday. Guidance in better agreement with the offshore
low, lifting it northward Friday and keeping it offshore. The
strengthening pressure gradient could produce gusty north to
northeast winds along the coast late Friday and Friday night. 1000-
500mb relative humidity decreases as the front reaches the local
area, with the best moisture located along the coast and offshore.
Will keep mention of slight chance to chance POP`s Thursday night,
ramping up to solid chance POP`s Friday as strong upper level
dynamics will likely overcome limited moisture. Could be a large
spread of daytime temperatures Friday, with highs expected to range
from the mid/upper 60`s northwest to mid(possibly upper) 70`s
southeast. Sticking with the slightly quicker ECWMF solution, the
front pushes offshore Friday night. Will keep low end chance POP`s
for the northeast half of the forecast area Saturday to account for
the uncertainty. Cooler Saturday with highs generally in the mid
60`s with a northwest wind. Dry Sunday as high pressure builds
across the Southeast. Highs generally in the mid to upper 60`s,
after morning temperatures in the 40`s to low 50`s.
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --High pressure will reside over the Carolinas through Wednesday
providing good flying conditions and southwest winds.
Patchy fog ended shortly after sunrise and a mainly clear sky is
expected for the remainder of the day with light winds. Will again
have to consider patchy fog for Tuesday morning but with southwest
winds...fog should be rather localized at best.
Outlook: Dry weather/VFR conditions are expected to persist through
Thursday. The next chance for showers arrives Friday as a cold front
passes/moisture increases due to an inverted trough off the Carolina
coast. Patchy fog will remain possible each morning, mainly around
-- End Changed Discussion --
Sfc high pressure will reside over the Carolinas through Tue...
resulting in S-SW winds aob 10kt today through Tue morning and
seas 2-4ft/waves 1-2ft. Meanwhile, a sfc low pushing through the
Upper Great Lakes Mon night and across SE Canada Tue/Tue night
will briefly tighten the sfc pressure gradient over the waters
Tue aftn/night. S-SW winds will average 10-15kt all waters during
this timeframe. High pressure briefly rebounds over the Carolinas
Wed through Thu as an upper trough/sfc cold front approaches the
Mid Atlantic Region from the west. Winds will remain sly around
10kt with seas 2-3ft/waves 1-2ft.
The cold front is expected to cross the waters on Fri as a coastal
low deepens well off of Cape Hatteras. The cold front should keep
the low out to sea, however an increase in NW winds due to decent
cold air advection and also an increase in seas/swell from the
nearby low should be anticipated Fri through at least Sat evening.
Best chance for SCA conditions for Bay/Sound/Mouth of James River
(NW 15-20kt/waves 2-4ft) will be Fri evening into Sat morning...and
through Sun morning for the coastal waters (NW 15-25kt/seas 3-5ft).
Winds/seas diminish Sun as high pressure builds into the area from
the SW and cold air advection wanes. Winds generally SW-W aob 15kt
with seas becoming 2-3ft/waves 1-2ft.
Astronomical tide information is not ingesting properly and has
resulted in missing data within the experimental total water level
hydrographs beyond 00Z Tuesday. Estimated return to service is Monday
Very warm conditions this week with the possibility of challenging
some records listed below:
* Record Highs
* Today (10/17) Tue (10/18) Wed (10/19) Thu (10/20)
* RIC 86 (1925) 88 (1938) 87 (1938) 89 (1984)
* ORF 87 (1925) 86 (2011) 87 (2007) 87 (1984)
* SBY 87 (1908) 86 (1908) 84 (1938) 84 (1984)
* Record high Mins:
* Tue (10/18) Wed (10/19) Thu (10/20)
* RIC 67 (1980) 73 (2007) 68 (1916)
* ORF 68 (1980) 73 (2007) 70 (1916)
* SBY 70 (1975) 71 (2007) 68 (1916)