Area Forecast Discussion
Issued by NWS Blacksburg, VA-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRNK 021447
Area Forecast Discussion
National Weather Service Blacksburg VA
947 AM EST Fri Dec 2 2016
High pressure will continue to build in from the southwest into
Saturday. The high moves overhead Sunday ahead of moisture that
will work into the area well in advance of a developing storm
system along the Gulf Coast early next week. This system should
track west of the region by Tuesday with a trailing cold front
working through the area during the middle of next week.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --As of 947 am EST Friday...Forecast is in pretty good shape to
this point in the morning. The only change I did opt to make was
to increase sky cover across far southwest Virginia and our
southeastern West Virginia counties though at least the early
afternoon hours. As is evident in morning infrared imagery and as
reflected in METARs at BLF, BCB and HSP, the southern fringe of of
OVC stratocumulus field is beginning to advance into the Alleghany
Highlands, southeast West Virginia and far southwest Virginia a
bit sooner than earlier indications. Temperatures appear on track
in these areas for now but may need to lower in later updates by a
couple degrees. Will monitor temperature trends in these areas for
now. Otherwise, no significant changes were made.
Previous near-term discussion issued at 400 am follows...
Northwest flow in the low level should persist this period while
surface high stays over the Gulf Coast states. During this period a
couple of vorts shift across the Central Appalachians and Mid-
Atlantic. Noticing models keep the clouds stuck into tonight in the
western slopes of WV and possibly far SW Virginia, with slight
chance for a rain or snow showers across western Greenbrier County.
As we head east though, should be sunny to partly cloudy today, with
some stratocu making it to the Blue Ridge. Some high clouds are
possible after dusk per upper jet, but still no more than partly
cloudy east of the WV/SW VA mountains.
We will keep temperatures close to early December norms today with
readings from the lower to mid 40s west, aside from some 30s on the
western slopes of Greenbrier per clouds, to 50-55 east.
Tonight should be similar, winds will be a determining factor on how
cold it gets, as with high still over the TN valley, some mixing
will still occur outside lower valleys. Lows will range from the mid
to upper 20s across the mountains to lower to mid 30s east.
-- End Changed Discussion --
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
As of 430 AM EST Friday...
The northern stream of the upper level pattern will be progressive
through the weekend, while a closed low forms over northern Mexico.
This will allow a series of short waves to move up from the
southwest for the latter portion of the weekend, followed by the
closed low opening up and ejecting toward the Appalachians during
the first part of next week. So after high pressure moving through
the Ohio valley brings quiet weather for the start of the weekend,
there will be increasing chances for precipitation especially
south of Route 460 over to the Mountain Empire of VA and northwest
mountains of NC where temperature profiles will favor some mixed
wintry precipitation and some patchy freezing rain late Saturday
night into early Sunday. Some additional wintry precipitation is
possible across western Greenbrier county late Sunday night. No
significant accumulations of wintry precipitation are expected.
By Monday, surface high pressure over New England and eastern Canada
will form a solid wedge down the east slopes of the Appalachians and
enhance isentropic lift ahead of the ejecting low. This will allow
better chances for precipitation to overspread the entire region from
the southeast very late Monday and Monday night.
.LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 430 AM EST Friday...
A surface low is forecasted to track into the Ohio Valley Tuesday. A
secondary surface low forms over the eastern Gulf states Tuesday
morning. This secondary low will bring the chance for moderate rain
into the region Monday night into Tuesday. This system will move north
of the region by Tuesday night.
Either Wednesday or Thursday of next week, a strong cold front will
bring bitterly cold temperatures to the area. Both the ECM and GFS
have Friday afternoon highs in the 20s across the mountains and 30s
east of the Blue Ridge. These are forecasted highs, not wind chills.
Until next week`s front crosses the region, temperatures will run
close to normal (mid to upper 40s west and low to mid 50s east).
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
As of 645 AM EST Friday...
Just stratocu to deal with this morning across the mountains WV
with high end MVFR to low end VFR cigs. Will see some scattering
out today but overall broken cigs to dominate scattered in
BLF/LWB. Appears rest of the area will stay VFR. Winds will stay
west to west-northwest around 6-12kts with some gusts to 18-24kts.
Winds should subside tonight with high pressure edging eastward.
Still some areas like Roanoke could see sustained winds around
Extended aviation discussion...
High pressure enters the area Saturday into early Sunday with VFR
conditions. Will start to see moisture stream northeast from a
low pressure system moving across the Gulf Coast states Sunday
into Monday with increasing threat of mainly rain. Will likely see
a period of sub-VFR cigs and possibly vsbys at most sites by
Monday but confidence is low as to how far north MVFR or lower
conditions will advance. A strong cold front will likely bring
more in the way of widespread sub-VFR in rain and low cigs on