Area Forecast Discussion
Issued by NWS Blacksburg, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRNK 310159
Area Forecast Discussion
National Weather Service Blacksburg VA
959 PM EDT Tue Aug 30 2016
A slow moving frontal boundary will drift into the region tomorrow and
bring a chance for showers and thunderstorms to the region, especially
along and west of the Blue Ridge, through Thursday. High pressure will
then build in from the upper midwest with cooler and pleasant weather
conditions expected for the end of the week and into the weekend.
.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --As of 955 PM EDT Tuesday...
Isolated showers will gradually dissipate overnight. Otherwise a
mostly clear sky, light wind and high amounts of low level
moisture will result in some valley fog developing once again
A weak frontal boundary will drift in from the northwest
Wednesday and give a boost to convective development during the
afternoon with coverage more widespread that what we have seen the
past few days. Orographic affects and unstable air pooling ahead
of the front will keep the best chance for thunderstorms along the
Blue Ridge. Little in the way of any severe threat as overall
synoptic support for organized convection continues to be absent.
Expect lows tonight in the mid/upper 60s east of the Blue Ridge with
low/mid 60s west. Highs Wednesday will be around 90 east to low/mid
-- End Changed Discussion --
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 345 PM EDT Tuesday...
Active tropical scene anticipated Thursday into Friday as area of
tropical low pressure moves from the eastern Gulf of Mexico to
along the southeast Atlantic Coast. This feature is progged to
steer clear of our forecast area, but should be monitored never the
less for changes (Please refer to WWW.NHC.NOAA.GOV for the latest
For much of the central Appalachians and points north, the
weather will be influenced by a deepening upper level trough which
is forecast to amplify over the Great Lakes and New England
Thursday. The associated surface cold front is progged to cross
our CWA during the day Thursday with potential for showers. Timing
of the front suggests little in the way of CAPE for thunderstorms
until front reaches the piedmont Thursday afternoon. The front is
forecast to clear the CWA by midnight Thursday night, dewpoints
and temperatures taking a noticeable tumble.
Model consensus is for the upper trough to provide an avenue for
the tropical system to follow as it passes off the mid Atlantic
coast late Friday. In its wake, high pressure will build in from
the north, resulting in a cooler drier airmass to infiltrate the
central appalachians yielding nice start to the Holiday weekend.
.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 400 PM EDT Tuesday...
Model consensus is for the long wave trough in the eastern CONUS
to linger Saturday before upper ridging returns over the Labor Day
Weekend. At the surface, a 1030 mb surface high is progged to pass
across the Great Lakes and into New England, wedging down the east
side of the Appalachians. Initially temperatures will be
pleasantly cool with readings 5 degrees or so below normal
Saturday, then inch upward a degree or two each day with near
normal temperatures to to start off next week and close out what a
lot of folks view as the wrap-up of summer.
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
As of 735 EDT Tuesday...
Isolated showers and thunderstorms will subside this evening with
quiet weather for the overnight period. Expect development of
fog/stratus again tonight with LIFR at KLWB, some IFR for KBCB,
and MVFR for KDAN. Highest confidence in the thickness of the fog
is at KLWB. Any fog/stratus will burn off early Wednesday morning
and believe the bulk of precipitation chances associated with a
weak frontal boundary drifting in form the northwest will hold off
until after 18Z. Areal coverage of thunderstorms Wednesday
afternoon will be too limited to include in the TAF at this time.
Overall, the best probability will be along the southern Blue
Extended aviation discussion...
A front will move into the region Thursday with a better chance
for MVFR/IFR showers/thunderstorms, followed by cooler and drier
air for Friday into Sunday. 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.