Scientific Forecaster Discussion
fxus61 krnk 121933
Area forecast discussion
National Weather Service Blacksburg Virginia
233 PM EST Tue Nov 12 2019
high pressure builds in for tonight into Thursday. Low pressure
rides along the southeast coast Thursday night into Friday.
Near term /through Wednesday/...
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 /Wednesday night 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 Monday/...
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 /20z Tuesday through Sunday/...
as of 100 PM EST Tuesday...
MVFR ceilings with isolated IFR conditions in snow showers
in the western mountains. Blf will have MVFR conditions the
longest. Sub-VFR conditions in rain and snow showers in the east
will scatter out to VFR this evening into tonight. VFR
conditions will return to all taf sites Wednesday.
Northwest winds will be blustery at 12-15kts
with gusts to 20-30kts, possibly higher at roa/bcb this evening
High confidence in ceilings,visibilities and winds during the
Extended aviation discussion...
VFR conditions continue Wednesday night into Thursday under
high pressure and for the mountains Friday. 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 Sunday.
as of 315 am EST Tuesday...
Temperatures will get close to some records for Nov 12 and 13
due to the Arctic air coming in behind the cold front. Listed
below are current records.
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 Wednesday for
NC...Winter Weather Advisory until 7 am EST Wednesday for ncz001-
WV...Winter Weather Advisory until 7 PM EST this evening for wvz508.
Wind Chill Advisory from 7 PM this evening to 7 am EST
Wednesday for wvz508.