Weather

770 
fxus61 krnk 281904 
afdrnk 


Area forecast discussion 
National Weather Service Blacksburg Virginia 
304 PM EDT Thursday Aug 28 2008 


Synopsis... 
as the moisture from Fay exits the area...a weak frontal boundary 
will approach from the west Friday night...slowly passing through 
the region through Saturday night. By Sunday and into next week... 
strong high pressure will build down from the Great Lakes into 
the southern Appalachians. 


&& 


Near term /through Friday/... 
short wave moving across the Tennessee Valley continues to spread 
moisture over lingering cold wedge. With some isentropic lift and 
easterly flow...light rain and drizzle is being reported across the 
mountains and mainly on eastern slopes of the Blue Ridge. After 
sunset...some lingering precipitation is expected but measurable amounts 
will be limited to 0.01 of an inch in isolated spots. Some pockets 
of drizzle may persist through the night but may be hard to detect 
with areas of fog and low clouds in the region through Friday 
morning. The Wedge is expected to erode during the day Friday as a 
cold front enters the Ohio Valley. Models eroding wedge a little to 
quick especially along the foothills. Not expecting any precipitation in 
the morning but kept overcast conditions in a little longer to 
account for this slow departure. A few isolated showers and 
thunderstorm could develop on eroding wedge boundary in the 
afternoon. 


Temperatures a little tricky giving wedge will be eroding through 
the day. Areas remaining in The Wedge through the afternoon may see 
a spike in temperatures late in the day and possibly in the evening. 


&& 


Short term /Friday night through Sunday/... 
cold front pushes through the Midwest Friday as western ridge begins 
building and shortwave trough along the northern tier of the U.S. 
Moves into the Great Lakes region. Models are in good agreement on 
this...however begin to differ once the front reaches the 
Appalachians and slides under the existing upper shear axis left 
over from this weeks storm. After bringing scattered showers and thunderstorms 
to the County Warning Area Friday night and Saturday and backdooring the County Warning Area Sat 
night...the front will tend to stall somewhere near the NC/Virginia line 
late Sat night into Sunday and may continue the chance of rain in 
the far south through the weekend. This occurs while a strong surface 
high builds over the Great Lakes. Eventually this high becomes 
strong enough to push everything well south of the forecast area as the 
upper ridge strengthens over the eastern U.S as part of an Omega 
block setting up across the northern states. 


&& 


Long term /Sunday night through Wednesday/... 
high amplitude Omega blocking pattern will prevail over the northern 
tier of the U.S. Monday through Thursday...translating into a strong 
surface high over the northeast and middle-Atlantic region. Meanwhile 
the remnants of Gustav are expected to track up the Mississippi Valley. 
Expect sunny warm days and clear comfortable nights through much of 
this period. 


&& 


Aviation /19z Thursday through Tuesday/... 
cold wedge to hold in place across the area and may strengthen 
overnight. Light rain and drizzle from a short wave in the Tennessee 
Valley continues to pump moisture over The Wedge of cooler surface 
air. Isentropic lift and upslope components will likely keep light 
precipitation and low flight restrictions in the region through Friday 
morning. Some ceilings and visibilities may reach MVFR this 
afternoon but drop back into the IFR/LIFR range overnight. Ridges 
will remain obscurred through the night. Visibilities will likely 
bounce around but generally remain MVFR through the night. 


With a frontal boundary entering the Ohio Valley Friday...The Wedge 
will slowly break through the day. Conditions should be improving to 
MVFR through the morning then VFR in the afternoon. Lyh will be the 
last to break out of The Wedge and flight restrictions could linger 
into the early afternoon. Late in the afternoon and into Friday 
night...showers will move across the mountains with the cold front. 
These showers will eventually move into the east overnight Friday 
and into Saturday morning. With the exception of Mountain Valley fog 
during the overnights...VFR conditions will prevail Sunday and into 
the middle of next week. 


&& 


Climate... 
Blacksburg may reach another record today for coolest maximum 
temperature. The current record is 69 in 1995. 


&& 


Rnk watches/warnings/advisories... 
Virginia...none. 
NC...none. 
WV...none. 


&& 


$$ 
Synopsis...ams/js 
near term...rcs 
short term...js 
long term...js 
aviation...rcs 
climate...