Area Forecast Discussion
Issued by NWS Blacksburg, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS61 KRNK 290556

Area Forecast Discussion
National Weather Service Blacksburg VA
156 AM EDT Fri Jul 29 2016

A frontal boundary will remain nearly stationary near the region
for the next several days. Disturbances moving along this boundary
will allow for periodic rounds of showers and storms. Hot and
humid conditions will continue into at least early next week.


As of 1215 AM EDT Friday...

WW419 has expired. Strong to occasionally severe storms continue
vcnty of Farmville. CAPE remains high (MLCAPE of 1500 j/kg) over
the piedmont, so as the outflow from these storms interacts with
this airmass, strong cores still possible. That said, loss of
daytime heating should result in decreasing intensity, but still
concerned that overall activity will persist well into the
overnight with possible training of lingering thunderstorm cells
along the tail end of vorticity and lingering dynamics aloft.
Since this training does not appear that it will impact the
previous Flash Flood Watch area (WV), the watch has been dropped.
If training of cells does develop, it may be closer to a RIC-FVX-
DAN line where existing outflow boundary becomes stuck between
stronger westerlies to the north and the upper level ridge over
the southeast U.S.

On Friday, much of the region will see a break in the
precipitation activity through the morning hours. We cannot rule
out isolated showers or storms across the west. By the afternoon,
our next approaching disturbance, along with daytime heating, will
help prompt additional shower and thunderstorm development.
Coverage is not expected to be as great as that anticipated this
evening. The best coverage will be in the west.

Low temperatures tonight will range from the mid 60s to the upper
60s across the mountains and around 70 to the lower 70s across the
Piedmont. Highs tomorrow are forecast to be just slightly lower than
those realized today. Readings around 80 to the mid 80s are forecast
for the mountains with upper 80s to lower 90s across the Piedmont.


As of 145 PM EDT Thursday...

Frontal boundary will stay just north of us Friday night with spoke
of upper energy moving east Friday evening. Timing of impulses is
problematic but seems next best wave works toward the PA/OH border
Saturday afternoon which may slowly nudge front southward. Appears
best threat of showers and storms will be focused from far Southwest
Virginia into SE WV and north of Highway 460 across Roanoke and
Lynchburg north Saturday afternoon with widely scattered further
south. Nonetheless kept pops no higher than 50.

Temperatures stay elevated at night thanks to high pwats with lows
from the mid to upper 60s west to lower 70s east. Saturday should be
at or just above typical late July values of lower to mid 80s west
to around 90 east.


As of 1150 AM EDT Thursday...

Belt of westerlies will be laying across the area Sunday night into
Monday, with front situated across the mid-Atlantic. Afterward the
upper flow takes on a more NW to SE orientation across our area as
ridge builds over the Central Plains. The front weakens but
convergence along it to remain through midweek. In addition, the
upper pattern favors potential ridge runners, where convective
clusters form over the upper midwest and shift southeast over our

Overall, will keep threat of showers and storms in the forecast all
periods but looks like Sunday-Monday have the better chance for
measurable rainfall.

May see slight nudge downward in temps early but overall humidity
levels should stay the same, so no appreciable dry air expected
thru Thursday.


As of 145 AM EDT Friday...

Satellite pictures and surface observations indicated an
extensive area of IFR to LIFR ceilings from the central
Appalachians into southwest Ohio and much of eastern Kentucky.
High confidence these clouds will remain over that area through
sunrise this morning. Lower confidence how far east the stratus
will spread. Have MVFR to IFR ceilings in at KBCB and KROA after
08Z/4AM. Ceilings will lift after 12Z/8AM and will be VFR for the
rest of the day.

Scattered showers and storms with MVFR ceilings and visibilities will
be possible across the mountains after 18Z/2PM.

At 06Z/2AM KLYH was reporting LIFR ceilings behind a line of
strong thunderstorms. Medium confidence than ceilings will lift
back up to MVFR early this morning.

Extended aviation discussion...

The area will remain in a relatively active period for showers and
storms through Tuesday thanks to a persistent, nearly stationary
frontal boundary across or near our region. Outside of the
precipitation and during the daylight hours, VFR conditions are
expected. Within the heavier showers and storms, and during the
overnight hours sub-VFR conditions are more likely.




AVIATION...AMS/DS is the U.S. government's official web portal to all federal, state and local government web resources and services.