Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 192333

Area Forecast Discussion
National Weather Service Blacksburg VA
733 PM EDT Tue Sep 19 2017

A weak shortwave will move east across our region tonight into
Wednesday. Jose should track north, off the east coast tonight
through Tuesday, before sliding just east of New England on


As of 700 PM Tuesday...

Afternoon and evening shower coverage remained extremely
isolated to the higher elevations Tuesday, with a weakening
trend expected to continue after sunset. Upstream shower
activity continues to stay well west of the forecast area
thanks to a stubborn layer of dry air in the mid levels, with
only decaying cloud debris noted spreading east into the
Appalachians by nightfall.

Previously Valid Discussion...
High pressure will remain across our area this afternoon into
tonight. Our forecast area will remain under dry air aloft
between Hurricane Jose passing well offshore and the next
upstream axis of deeper moisture associated with a cluster of
mid level shortwave energy in the Midwest.

A weak surface cold front to the northwest slowly edging east
towards the mountains late tonight. Low level moisture and light
winds will result in patches of fog especially in the valleys.
Low temperatures tonight will range from the the mid 50s in the
mountains to the mid 60s in the piedmont.

Wednesday will feature another warm afternoon with high temperatures
from around 70 degrees in the northwest mountains to the mid
80s in the Piedmont. Shortwave will slide east across the area
and be enhanced by diurnal heating. The cap will weaken enough
to allow for isolated to scattered showers and thunderstorms
along and west of the Blue Ridge mountains.


As of 248 PM EDT Tuesday...

A rather quiet weather pattern with little change in the low
level/upper level features. Will be relying on daytime heating and
weak upper impulses, along with some weak low level convergence for
isolated to scattered showers/storms Thursday-Friday afternoons.

Will seem more like summer like pattern though not as hot, but temps
will still run 3 to 10 degrees above normal.

Lows will run from the mid to upper 50s mountains, to lower to mid
60s foothills/piedmont and Roanoke.

Highs mainly upper 70s/around 80 west, with mid 80s east.


As of 130 PM EDT Tuesday...

Surface and upper ridge will be sandwiched between tropical systems
off the east coast and strong upper trough over the central/western
U.S. this period. Will see how Hurricane Maria evolves and tracks
northward off the east coast next week, depending on how Jose
moves/weakens and if the upper ridge pushes further off the mid-
Atlantic coast.

At present, models in decent agreement keeping us on the warm and
dry side. Highs and lows will continue to range about 3 to 8 degrees
above normal.


As of 135 PM EDT Tuesday...

Mainly VFR East of the Blue Ridge tonight, with IFR VSBYs
possible at LWB/BCB just before sunrise. MVFR to brief IFR
conditions possible at BLF also thanks to potential fog

Sticking with a primarily persistence type forecast overnight
tonight, with little in the way of airmass change compared to
previous nights expected. A wild card tonight will be potential
cloud cover, introduced thanks to a weak impulse pushing across
the Ohio River Valley. Trend has these residual showers and
clouds burning off before spilling east of the Blue Ridge, but a
SCT to BKN deck could delay BR/FG formation in LWB/BLF/BCB by
an hour or two. Otherwise, expect gentle downsloping winds east
of the Blue Ridge, keeping conditions quiet for any overnight

Showers are expected to be a bit more numerous tomorrow across
the higher elevations. Should remained scattered in coverage at
most, but an introduction of SHRA or brief dips to MVFR Ceilings
in the localized downpours will not be out of the question in
the mountains. Have left these out at specific sites for now
thanks to lower confidence.

Extended Aviation Discussion...

Overall persistence forecast to prevail for the rest of the
upcoming week into the weekend with strengthening high pressure
remaining in place between exiting Jose offshore and a weak
cold front approaching from the west. This should maintain good
flying weather outside of early morning fog/stratus through late
next week, with only isolated to scattered diurnal showers
possible Wednesday evening and Thursday afternoon as upper
level energy slides across. Isolated MVFR convection is
possible Friday in the southwest mountains. Dry weather is
expected Saturday and Sunday.




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