Area Forecast Discussion
Issued by NWS Blacksburg, VA

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FXUS61 KRNK 010020

Area Forecast Discussion
National Weather Service Blacksburg VA
820 PM EDT TUE MAY 31 2016

Our weather will remain unsettled through the end of the workweek as a
weak cold front slowly moves in from the northwest and keeps showers
and thunderstorms in our forecast into the weekend. The weekend also
looks to be rather wet as more showers and thunderstorms will develop
ahead of another cold front that will move through the region Sunday


As of 645 pm EDT Tuesday...

Convection late this afternoon and early evening has been
primarily confined to those parts of the region along and west of
Interstate 77. A few isolated showers were also in parts of the
Greenbrier Valley in West Virginia and also in the James River
basin east of Lynchburg. As we head into the evening hours the
loss of sunshine will take away the fuel that has been triggering
the activity. Expect a general trend towards less coverage but
within the same geographic region as the current coverage. The
isolated showers in the James River basin should continue a
southerly progression towards the VA/NC border. Have made minor
tweaks to hourly temperatures and dew points to capture the latest
observations and trends through the evening hours. The biggest
adjustment will be in the southwest portion of the forecast where
there is rain cooled air in some locations.

As of 315 PM EDT Tuesday...

Diurnal convective activity will gradually wind down this evening with
an isolated renegade shower possibly stewing around through the
overnight hours. The humid conditions will once again favor fog/stratus
development tonight through early Wednesday morning...being
particularly thick in locations that experience rain this afternoon and
evening. Lows tonight will be mild with generally low/mid 60s east to
upper 50s/around 60 west.

The pattern will not change significantly through midweek. The remnant
circulation of Bonnie will continue to swirl along the Carolina coast
with high pressure in a wedge-like configuration east of the Blue
Ridge. This will result in diurnally forced convection through the
period with orographic affects and differential heating boundaries
serving as initiation and keeping the bulk of convective activity from
the Ridge westward on Wednesday...though model trends are also
wanting to rotate some convection into the piedmont and eastern
Southside VA later in the day as well. Temperatures will continue
to run a few degrees above normal with elevated dew points making
for sticky conditions.


As of 315 PM EDT Tuesday...

Weak ridging aloft will transition into zonal flow with the main storm
track well to our north. This will prevent any major systems from
moving through the region...however a weak frontal boundary will sag
through the region by the end of the week. This will enhance our
chances for diurnal convection and also increase the coverage of
showers/thunderstorms on both Thursday and Friday. As the boundary gets
hung up just to our south waves will ripple along the baroclinic zone
and may well make for a wash out of at least the latter portion of
Saturday. Tempertures look to remain at or above normal with a slight
cooling trend especially west of the Blue Ridge associated with the
transit of the frontal boundary.


As of 330 PM EDT TUESDAY...

A vigorous upper trof will dig through the Great Lakes region this
weekend culminating in a closed low spinning over New England through
the first part of next week. This will drive a surface low from the
upper plains into New England and push a cold front through the region
on Sunday night. This will generate widespread coverage of showers and
thunderstorms ahead of the front on Sunday and make for a soggy close
to the weekend. Cooler air will then move in behind the front for the
first part of next week along with improving conditions save for
locations west of the Blue Ridge where upslope conditions in NW flow
will keep a chance of showers in the forecast.


As of 745 PM EDT Tuesday...

Little change expected in the weather pattern through the period...with
a weak tropical low...remnants of Bonnie...persisting along the
SC/NC coast...and a deep trough persisting in the Southern Plains.
This leaves the region with weak east-southeast flow and the best
convergence across the mountains of southwest VA and northwest NC.
Look for a similar setup Wednesday.

Showers/thunderstorms this evening have been confined to areas
mainly west of I-77...and the activity is diminishing quickly and
will continue to do so with the loss of daytime heating. Concern
through the overnight hours will be for development of low clouds
and fog...which seems likely based on easterly maritime flow and
weak upslope. Fog/low clouds should be most problematic at
KLWB/KBCB and potentially in previous mornings. A period
of LIFR-VLIFR cigs/vsbys likely at KLWB/KBCB as was observed this
morning. Otherwise...looking at mostly VFR cigs/vsbys through the
TAF valid period. Scattered showers/thunderstorms should develop

Winds will remain east-southeast 5-8kts through the period.

Medium confidence in cigs and vsbys through the TAF valid period.
Medium to high confidence in wind spd/dir through the TAF valid
Medium confidence in TSRA potential Wednesday afternoon.


Outside of early morning fog/low clouds and afternoon/evening convection
should be VFR through the end of the week. Finally a stronger
upper trough will kick what is left of Bonnie out to sea Thursday-
Friday. Expect more widespread showers Thursday afternoon into
Friday ahead of a cold front, making for periods of sub-VFR
ceilings and visibilities. Saturday may be VFR behind this front
and before moisture and lowering conditions return by Saturday
night. Sunday looks to bring a good chance of showers and
thunderstorms to the CWA with a strong cold front/upper trough.




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