Area Forecast Discussion
Issued by NWS Wakefield, VA-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KAKQ 272034
Area Forecast Discussion
National Weather Service Wakefield VA
434 PM EDT Tue Sep 27 2016
A cold front stalls near the Virginia-North Carolina border tonight
through Wednesday morning. Low pressure tracks north across the
North Carolina and Virginia piedmonts Wednesday afternoon and
night. An upper level low slowly drops south from the Great Lakes
region resulting in unsettled weather conditions into the weekend.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
-- Changed Discussion --Quick update to lower PoPs across interior portions of FA. Keeping
PoPs 50-70% from VA Eastern Shore to coastal NE NC until mid-late
evening. Partial clearing also will occur inland...especially
along-W of I 95 corridor.
Latest MSAS showing the cold front basically splitting the fa in
half NE- SW. Band of convection ahead of it will continue to move
east and off the coast this evening. Pcpn has basically ended
across the piedmont with partial clearing across wrn zones.
Boundary progged to stall along the VA/NC border tonight as low
pressure across the NC piedmont begins to track NE after 06Z. Pops
will be based off of radar trends but the jist will be for higher
pops this evening across the SE. Some weak lift noted behind the
boundary after midnight so kept low chc pops. Attention then goes
to fog development as the latest guidance is showing the potential
for widespread fog after midnight. Added areas of fog to the grids
after 06Z. Lows in the 60s.
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.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Interesting forecast for Wed and Wed nite. Potent s/w energy (triple
point low) progged to slowly track north along the I95 corridor.
After morning shwrs and areas of fog, expect nmrs shwrs and tstrms
to develop. The strength of the storms will likely hinge on whether
any sun will aid in heating. SPC has areas along and west of the I95
corridor in marginal risk with the threat being damaging wind gusts.
Locally heavy downpours are also possible. Will carry likely pops
after 18Z. Highs from the mid 70s NW to lwr 80s SE. Lows in the mid
60s NW to near 70 SE.
Upper level (cut off) low progged to slowly sink south from the
Great Lakes region Thurs then stall across KY Thurs nite before
beginning to slowly drift NNE Fri. Strong and persistant onshore
flow around this feature will add to the available moisture and cool
pool instability to produce widespread showers with embedded tstrms.
Upslope conditions will likely produce pockets of moderate to heavy
rainfall across northern most zones on northward. Thus, kept chc to
likely pops going for most of Thurs through Friday. Highest pops
across the north. Highs Thu in th mid 70s to lwr 80s. Lows in the
60sto near 70 SE. Highs Fri 75-80.
Total QPF west of the Ches Bay expected in the 2 to 4 inch range
with 1/2 to 1.5 inches along the coast. No flood headlines
anticipated at this time given the time frame that the rainfall
will occur over. Significant rises in river levels are possible
later this week if we do get the expected QPF across the headwaters.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Long term period starts off Fri night/Sat with an upper-level cutoff
low and associated sfc low centered over the OH Valley. Better rain
chances will stay north of the area, but included at least a 20-30%
chance of showers especially over ne areas where the highest
moisture will be located. Mainly dry conditions thereafter into Sun
and Mon as the cutoff low weakens and slides ne into Canada. As for
temps, highs will generally be in the mid/upper 70s with lows
ranging from the mid/upper 50s over the Piedmont to the mid/upper
60s near the coast.
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
Cold front crossing the region as of 18Z. PCPN to end soon at
RIC/SBY but just getting started across SERN TAF sites. Given the
sporatic nature to the shower activity, decided to add a TEMPO
group for lower CIGS/VSBYS in showers as some mdt to lclly heavy
rainfall reported across the region. Kept thunder out attm given
no lightning strikes anywhere across the fa, but that could
quickly change over the next few hours as the front moves into
the warmer air near the coast.
Sct showers end this evening with the attention turning to fog
potential tonight given a wet ground and high dew point temps.
Have indicated MVFR conditions late tonight at all sites except
ORF, with some guidance taking progging locally dense fog towards
Next batch of pcpn advances norhward across the piedmont after 12Z
as low pressure along the front moves north. Thus, brought back
rain to RIC but kept coastal areas dry for now.
OUTLOOK...Unsettled weather conditions expected through the end
of the work week as waves of low pressure lift along the cold
front. Showers with late day tstms possible each day.
Latest sfc analysis shows a stalled frontal boundary over the local
area. The frnt remains in the vicinity through Wed leading to sub-
sca conditions with 1-2 ft waves over the Bay and 2-4 ft seas over
coastal waters. The front then lifts northward Wed night/Thu, and
with strengthening high pressure over SE Canada/New England, seas
will ramp up. Hoisted a sca for the northern coastal waters for Wed
night/Thu with prolonged easterly fetch, which may need to be
extended past the fourth period in future updates. 5 ft seas may
also possibly affect the southern coastal waters as well. Overall
winds will avg 10-15 kt through the period, up to 15-20 kt over
northern coastal waters at times.
MARINE...Small Craft Advisory from 7 PM Wednesday to 7 PM EDT Thursday