Area Forecast Discussion
Issued by NWS Wakefield, VA
FXUS61 KAKQ 280231
Area Forecast Discussion
National Weather Service Wakefield VA
1031 PM EDT Tue Sep 27 2016
A cold front stalls near the Virginia-North Carolina border 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/...
Weak frontal boundary stalls invof srn VA/near the VA-NC border
overnight. Combination of recent rainfall/ground moisture and light
winds to lead to fog. Model profiles favor most widespread fog
along/E of I 95...stratus W (as weak impulse aloft becomes to
develop area of at least SCT shras NNE across the piedmont). Will
not pull trigger on dense fog advisory...trends overnight may
change that. Otherwise...PoPs to 50-60% W...to 15-30% at the
coast. Mostly cloudy with lows in the l60s NW to the u60s SE.
.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 /03Z WEDNESDAY THROUGH SUNDAY/...
A cold front has continued to slowly push through the region and
is now located near the coast. IFR conditions continue to be
present at SBY due to residual showers/lower ceilings (600ft),
added a TEMPO group for to take account for this. Also added a
TEMPO group at RIC for the possibility of lower ceilings over the
next few hours. VFR conditions are expected at the remaining TAF
sites for the first half of the night.
Tricky forecast is in store for the rest of the night with
the potential for fog across the area. Introduced IFR conditions
by 04Z for SBY and 06Z for RIC due to highest confidence of fog
potential. Brought MVFR into all other TAF sites. Model guidance
still hints atthe potential for some locally dense fog towards
Next batch of precipitation will approach the piedmont as
low pressure along the front begins to move north later
tonight. Introduced VCSH at RIC after 06Z due to some uncertainty
with initial timing and coverage of the showers.
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 thunderstorms will be possible each
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