Area Forecast Discussion
Issued by NWS Blacksburg, VA
FXUS61 KRNK 282351
Area Forecast Discussion
National Weather Service Blacksburg VA
751 PM EDT Sun Aug 28 2016
A weak frontal boundary will begin to approach from the north Monday,
then stall and linger in our vicinity through the middle of the week.
This will keep just a chance of an afternoon shower or storm in the
forecast, mainly west of the Blue Ridge, with warm late summer
temperatures near normal.
.NEAR TERM /THROUGH MONDAY/...
As of 330 PM EDT Sunday...
Any lingering isolated showers will dissipate this evening and allow
the wedge of high pressure over the region to bring quiet weather for
the overnight period with conditions a bit more favorable for valley
fog development late. Lows tonight will generally be in the mid/upper
60s east of the Ridge with low/mid 60s west.
For Monday, as the upper ridge flattens and gets squeezed a bit to the
west as a vigorous short wave moves through New England. This will
allow a weak boundary to sink into the area from the northwest and
bring a good chance for more showers/storms to southeast WV and the
Alleghany Highlands of VA, with an isolated shower/storm possible
extending back west of the Blue Ridge to the Mountain Empire of VA.
Aside from this, the bulk of the Appalachians and central mid Atlantic
region will see a quiet and warm late August day to start the week.
Highs tomorrow will be near 90 degrees east to mid/upper 80s west.
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
As of 345 PM EDT Sunday...
Upper ridge of high pressure is forecast to weaken as series of
short wave troughs skirt the US/Canadian border carving out a
broad trough from the Great Lakes into New England by Wednesday.
First of two surface fronts will enter the CWA Monday night. This
front is expected to stall over the forecast area becoming the
focus for scattered showers and thunderstorms both Tuesday and
Wednesday. A second front will approach the forecast area
from the north Wednesday night, as a much stronger short wave
rounds the base of the upper level trough.
As the upper level ridge breaks down, temperatures will also
trend down, although still averaging above normal through at least
.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 400 PM EDT Sunday...
Models continue to advertise a much sharper upper level long wave
trough developing from Ontario Canada to the Mid Atlantic by the
end of the week. Associated surface front is forecast to come
through our forecast area Thursday, a transition to a cooler drier
airmass by Friday. In spite of the cooling and drying progged for
our CWA, the tropics are forecast to be busy, with potential
impacts to Florida and nearby states. The upper trough which
sets up over the eastern US will likely play a large role in
steering the near CONUS tropical systems during this period.
Please refer to The National Hurricane Center for the latest
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 745 PM EDT Sunday...
Radar trends at 23Z/7PM showed thunderstorms in southeast West
Virginia weakening and dissipating. No chance of precipitation has
been included in the local TAFs.
Conditions overnight appear favorable for radiational cooling and
moisture profiles indicated by model soundings favor some
fog development late especially for KBCB and KLWB. There is also
a strong signal from the NAM soundings for a layer of strato cu
developing in a similar manner to Saturday night. Will include a
mention of these clouds but will leave them as scattered and not
create a cig The more clouds that form, the less likely there will
be MVFR or lower fog. Any fog/stratus will burn off early Monday
morning with VFR conditions expected through the end of this valid
period. Winds will be light.
High confidence that a majority of the thunderstorms on Monday
afternoon will remain just northwest of KLWB. This will be just
ahead of a weak front the will approach the region Monday
afternoon then dissipate by Monday night.
Extended aviation discussion...
Isolated diurnally driven convection will be possible Tue.
Coverage will be limited in duration and area on all days and have
minimal impact on the TAF sites. Another front will move into the
region Wed into Thu with a better chance for showers/thunderstorms,
followed by cooler and drier air for Friday. Most of the period
looks VFR at this point, outside of the usual late night/early
morning fog/low clouds. At this time, it does not appear that any
tropical systems will impact the county warning area.