Area Forecast Discussion
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FXUS61 KAKQ 291812
Area Forecast Discussion
National Weather Service WAKEFIELD VA
212 PM EDT Wed Mar 29 2017
A cold front pushes farther offshore this morning. High
pressure builds across the northeast today, before it retreats
to the northeast on Thursday. A strong system is expected to
impact the region Friday and Friday night. Dry weather returns
for the weekend.
.NEAR TERM /THROUGH TONIGHT/...
SCT to BKN SC/AC should thin out as the days progresses due to
drier air filtering in from the north. Expect a pt to mstly
aftn as high pressure builds in from the north. Highs 60-65F
near the coast and in the upper 60s to lower 70s well inland.
Upper ridging pulls overhead tonight as upper trough lifts
across KS/OK late tonight. At the surface, high pressure nudges
south from Eastern Canada/New England tonight, with low level
flow becoming E-NE and increasing. Lows in the mid 30s to near
40 across far northern zones, low to mid 40s farther south...mid
to upper 40s along far SE coastal zones. Sky begins mainly
clear, but expect some increasing mid to high clouds toward
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Dry Thursday, with upper ridge in place overhead. However, WAA
aloft atop the stable onshore flow will likely result in partly
to mostly cloudy sky Thursday and model BUFR soundings continue
to suggest mostly cloudy to overcast conditions inland by 18z
Thu (partly sunny eastern sections). Given weak/low mixing and
the increase in clouds, expect a much cooler day with highs
mainly ranging from the lower to mid 50s near the coast to the
upper 50s over interior eastern VA/northeast NC.
Models coming into increasing agreement with handling of
previously mentioned upper low currently pushing slowly across
the Southern High Plains. 00z NAM has come into better agreement
with the GFS/ECMWF solutions, which all feature a strong closed
low lifting across the Missouri Valley, and taking on a
negative tilt as it lifts across IN/OH by Friday morning. Good
model agreement exists with respect to onset of showers and
embedded t-storms late Thursday night/Friday Morning from west
to east. Similarly good agreement with respect to potential for
widespread showers/tstms and potential for heavy rain during
Fri, which makes sense given the negative tilt, PW values in the
1.25-1.5" range (>150% of normal) and flow aloft parallel to
the encroaching frontal boundary. quickly expand pops just
before sunrise west of I-95 before increasing to 80% to 90% all
areas during Fri morning.
Categorical pops continue Friday aftn as the upper low tracks
east across the mountains Friday afternoon and night. There
remains every indication that we`ll have the chance for some
strong to locally severe storms once again during this time
frame. Given the trend towards the quicker solution, storms will
move out quicker and there will be less time for diurnal
destabilization, so it is certainly a conditional threat.
That said, strong 0-6km shear values, Lifted Indices of
<-4 deg C coincident with timing of best forcing onset Friday
aftn would at least argue favorably for continued mention of
thunder in grids, especially across the southern 2/3 of the
area. Lowered pops Friday night given quicker timing, with
clearing into Sat morning. as front crosses the area late
Friday. Highs in the 60s to near 70. Lows Sat morning in the low
to mid 50s, with some upper 40s across our far northern tier of
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Low pressure and associated surface cold front cross the area
Friday night then moves off the coast. Dry wx and high pressure
returns for Sat thru at least Mon morning. Yet another system
will bring the chc for showers back to the area late Mon thru
Highs in the mid 60s to lower 70s Sat, in the 60s to near 70
Sun and Mon, and in the 60s to lower 70s Tue. Lows in the upper
40s to mid 50s Fri night, in the 40s Sat night and Sun night,
and in the mid 40s to lower 50s Mon night.
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
High pressure ridge extending from a center over the James Bay south
into the Mid Atlantic States will slip slowly to the east. Strong
low pressure over the southern Great Plains will move northeast into
the Ohio Valley by Thursday night.
Stratocumulus over interior Virginia and North Carolina will
continue to erode from north to south. Have RIC PHF and ECG with
MVFR cigs for the first couple of hours of the 18Z TAF. The sky will
be mostly SKC this evening and overnight. Layered cloudiness
increases from the west on Thursday but will remain VFR through 18Z.
No visibility issues are indicated through Thursday morning.
Winds will be from the north and northeast at around 10 knots during
the balance of the afternoon. Winds will be less than 5 knots from
the northeast and east overnight and mainly easterly 5 to 10 knots
on Thursday morning.
OUTLOOK...The aforementioned low pressure system will move from the
Ohio Valley across northern portions of the Mid Atlantic States to
south of New England by Saturday morning. Widespread rain develops
Friday morning which will combine with a chance for thunderstorms
Friday afternoon and evening. Periods of MVFR/IFR will be
likely. Conditions improve by Saturday morning. High pressure
builds back into the area for the weekend. There will be a
chance for showers western portions of the area by late Monday
as the next system develops over the Mississippi Valley.
Winds have not increased as much as expected and are generally
10 kt across the Bay and lower VA coast. have lowered wind
speeds for today some and may need to lower them even more with
the early afternoon to update. Generally expect n to ne winds
around 10 kt with slightly higher winds gusting to 15 kt from
Wallops Island north to Ocean City.
Latest sfc analysis shows a cold front sliding off the Carolina
coast with high pres over the Great Lakes region. The front
will push farther offshore today as the high builds north of the
region. Resulting north winds will increase this morning in
association with weak CAA/pres rises. Conditions just sub-SCA
tonight with NE flow of 10-15 ft over the Bay/rivers/Sound and
15-20 kt over coastal waters. Similar conditions into Thu
morning with seas near 5 ft out 20 nm over the coastal waters.
Next cold front then approaches from the west Fri, with marginal
SCA S/SE flow expected ahead of the front. This front crosses
the waters late Fri night/Sat morning.