Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Blacksburg Virginia
1228 am EST Wed Nov 13 2019
Arctic high pressure builds in for tonight into Thursday
bringing the coldest temperatures to the area since last winter.
Low pressure rides along the southeast coast Thursday night
into Friday, bringing some clouds and our next chance for
precipitation, mainly to the Piedmont areas. Temperatures will
moderate during the next few days.
Near term /through today/...
as of 730 PM EST Tuesday...
The Winter Weather Advisory for snow in western Greenbrier has
expired. The Wind Chill Advisory remains in effect until 7 am
EST for western Greenbrier County. The Winter Weather Advisory
covering the concerns for snow and strong wind gusts continues
across northwest NC into the Blue Ridge of southwest VA, roughly
Watauga to Floyd through 7 am EST Tuesday.
Lingering snow flurries in the blf-lwb area, and perhaps in far
southwest Virginia and northwest NC mountains, but for the most part
the snow has ended across the County Warning Area. Winds are diminishing, with
the strongest gusts now in the 25 to 30 mph range (roa and gev).
Conditions will continue to improve overnight into Wednesday.
However, coldest temperatures tonight since late last winter
(early march) with lows ranging from around 8f at Burkes Garden
to near 20 in the southeastern parts of the Piedmont. Winds will
continue to diminish to 5 to 15 mph overnight with gusts ending
late tonight/early Wednesday. Winds will veer around to the
northeast early Wednesday. Other than the cold temperatures,
15-20 degrees below normal Wednesday, it will be a sunny/quiet
As of 138 PM EST Tuesday...
Winter weather advisories remain in effect tonight for western
Greenbrier and along the southern Blue Ridge mountains.
The back edge of the main precipitation area with rain and snow
should exit our forecast area during the next couple of hours. While
some snow showers and snow flurries linger in the western mountains.
The hiresw-arw-east and NAM showed some snow showers and snow
flurries lingering into this evening. However, the trend of
models has been to trim back the upslope snow showers and
flurries. Regional radar images indicated some scattered snow
showers to our west across the Ohio Valley.
Behind the cold front, gusty northwest winds will usher in very
cold air tonight. Hires models like namnest continue to show
another window for gusty wind tonight across high terrain with
pressure rises and a low level jet slide across region. Gusty
winds and chilly wind chills are main concern along southern
Blue Ridge. Clearing is expected east of the mountains this
afternoon into tonight, with lingering upslope clouds and
isolated snow showers and flurries across the mountains into
early evening before clearing overnight.
Wind chills will fall into the negative single digits at the
higher elevations tonight with single digits above zero to teens
elsewhere. Low temperatures will range from the single digits
in the mountains to around 20 degrees in the Piedmont.
Canadian high pressure will build east across our region Wednesday.
Under plenty of sunshine, high temperatures Wednesday will range
from the upper 20s in the mountains to the lower 40s in the
Short term /tonight through Friday night/...
as of 232 PM EST Tuesday...
A cold dry Canadian high pressure will continue to sit over the
region into Thursday. A northern stream system will begin to phase
with the southern stream Gulf disturbance Thursday night. These two
systems will generate a surface low that will track across northern
Florida Thursday night then along the Carolina coast Friday and
Friday night. With the track of the low staying south of the area,
precipitation may edge north into Southside Virginia beginning as early as
Thursday evening and exiting by midday Friday, elsewhere will remain
dry. Since temperatures are expected to warm and remain above
freezing, precipitation will fall as a cold rain. Rainfall amounts
should not exceed two tenth of an inch.
Daytime temperatures will remain colder than normal Thursday by 10f-
15f, while moderating some on Friday to 5f-10f cooler than normal.
Normal temperatures for this time of year range from the mid to
upper 50s across the mountains (upper 40s across higher elevations)
to low to mid 60s east of the Blue Ridge.
Overnight temperatures will also remain cooler than normal with
readings Wednesday night in the upper teens across the mountains to
lower 20s east of the Blue Ridge. Nighttime lows return to normal
Thursday night and Friday night.
Long term /Saturday through Tuesday/...
as of 232 PM EST Tuesday...
The system off the Carolina coast will become an occluded low, but
will stay off the coast through the weekend. Early next week, a cold
front tracking across the Ohio and Tennessee valleys will push the
coastal low further out to sea. However, this front will have a new
low pressure system with it, coming out of the Gulf and along the
East Coast next week. Unlike this weekend system, the low with the
front will move north very quickly.
Temperatures will remain slightly cooler than normal over the
weekend, then moderate towards normal through mid week.
Aviation /06z Wednesday through Sunday/...
as of 1200 am EST Wednesday...
MVFR ceilings continue mainly across the western mountains from
tnb-hlx-tnb-hsp and westward. These clouds should linger until
nearly daybreak based on latest trends. In addition, there are
still snow flurries and occasional heavier snow showers as
northwest flow trajectories bring moisture from the Great Lakes
toward the southeast and upslope areas/ wind will become less
orthogonal to the alleghanys around daybreak. VFR elsewhere.
All areas should be VFR after 13z Wed. No restrictions expected
to visibility throughout the taf valid period, except where a
heavier snow shower occurs, which may create a very brief period
of MVFR conditions.
Winds continue to slowly diminish. Strongest gusts this hour in
the 15-20kt range, expected to decrease further throughout the
night as high pressure builds in. Winds will veer more to north and
north-northeast late tonight/early Wednesday, then to NE-east-northeast through the
day tomorrow in most areas. Speeds after 12z Wed should be
mainly in the 5-10 mph range.
/Confidence levels in forecast parameters/
ceilings - moderate to high,
visibilities - high,
winds - moderate to high.
Extended aviation discussion...
VFR conditions continue Wednesday night into Thursday under
high pressure. Models showing potential southeast coastal
system moving moisture toward Dan Thu night- Fri which could
bring ceilings toward low end VFR. Otherwise VFR Saturday and
as of 745 PM EST Tuesday...
Blf coming very close to their record low for the date of 15
degrees, with the latest temperature at 17. Other records appear
too low to reach today, but a few may be in jeopardy of being
set on Wednesday. Both record low minimum and record low
maximum temperatures are in jeopardy of being reached on
Sitecoldest highs/year coldest low/year
Bluefield 30/1983 15/1950
Danville 36/1987 21/1941
Roanoke 39/1983 17/1926
Blacksburg 29/1987 17/1973
Sitecoldest highs/year coldest lows/year
Bluefield 28/1976 10/1911
Danville 41/1968 20/2016
Lynchburg 36/1911 20/1996
Roanoke 38/1976 19/1920
Blacksburg 34/1968 15/1983
Virginia...Winter Weather Advisory until 7 am EST this morning for
NC...Winter Weather Advisory until 7 am EST this morning for ncz001-
WV...Wind Chill Advisory until 7 am EST this morning for wvz508.