Roanoke, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

110
FXUS61 KRNK 030930
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
430 AM EST Tue Dec 3 2024

.SYNOPSIS...
Light snow tapers off this morning. High pressure returns
today and Wednesday, allowing for mostly sunny skies eventually
and cold temperatures. Another cold front is expected to bring
mountain snow showers Wednesday night into Thursday, along with
very gusty winds. Another shot of colder air arrives behind
this system for Friday into the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 245 AM EST Tuesday...

Key Messages:

1) Cold but sunny for much of the area today. Clouds gradually
diminishing for the mountains.

2) Extremely cold tonight.

Weak short wave trough which brought some light snow to the
mountains and perhaps a dusting to parts of the piedmont has
mostly moved out of the area. Dry air at the surface likely
kept some of the snow seen on radar from reaching the ground.

Dense high pressure currently over Missouri shifts south and
east today, keeping cool northwest flow in place. Skies will
become sunny first southeast of the Blue Ridge and then
expanding north and west, with stratus gradually diminishing
during the day for the mountains. Dew points remain very low,
with PW values on last night`s KRNK sounding less than 10% of
normal for that day/time...around 0.15 inches. Cold air
advection remains significant especially in the mountains, and
expect highs in the mid 20s to low 30s there. Southeast of the
Blue Ridge highs will be in the mid 30s to low 40s.

High pressure is pushed towards the Deep South tonight as the
next weather-maker moves out of central Canada. Overall
moisture ticks up a little late tonight as mid level moisture
sinks in from the north. At the surface we will still have very
dry air. Lows will range from about +10 to +20 across the
forecast area, with higher elevations a little warmer and
benefiting from some weak WAA.

Temperatures today will not be cold enough to break any records,
but tonight into Wednesday morning Bluefield may tie or break
it`s 9 degree record. See Climate section below.

Confidence in the near term is high.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
As of 345 AM EST Tuesday...

Key Messages:

1). Another significant surge of Arctic air expected Thursday
through Friday.

2). Strong and gusty northwest winds expected Wednesday night
and Thursday. High Wind Watch/Warning possible for the mountains
of WV into far southwest VA Wednesday night into Thursday.

3). Very cold, much below normal temperatures Thursday through
Friday. Cold Weather headlines possible.

4). Accumulating snow likely mountains of eastern WV through
southwest VA Wednesday night through Thursday morning. Minor
accumulations of snow possible as far east as the Blue Ridge.

A broad and deep upper-level low will remain anchored over the
Great Lakes to Hudson Bay with northwest flow well established
from central Canada into the southeastern U.S. An embedded
short wave will track through the base of the upper trough and
bring yet another significant surge of Arctic air into the
region beginning Wednesday night and then settling over the
region for Thursday into Friday morning. 850mb temperatures within
the core of this air mass are around -18C. Thus, the
forthcoming air mass is even colder than the air mass just now
beginning to lift out of the area.

This surge of Arctic air will bring some weather hazards to the
area in the form of (1) strong and gusty northwest winds,
potentially gusting over 50kts Wednesday night into Thursday
morning, (2) very cold temperatures and wind chills Wednesday
night and Thursday morning, and (3) accumulating snow to the
mountains of eastern WV into southwest VA. A High Wind Watch was
contemplated for a strip of counties mainly through the
Alleghanys of eastern WV into the Cumberland mountains of
southwest VA and the NC High Country, but in coordination with
neighboring offices, it was decided to delay such issuance for
another forecast cycle. The strong cold advection and upslope
winds across the mountains from eastern WV into southwest VA
will bring periods of snow showers, possibly moderate to heavy
at times especially Wednesday evening into early Thursday
morning. Snow squalls cannot be ruled out Wednesday night/early
Thursday, especially in western Greenbrier. The combination of
snow, strong winds, and blowing snow during this time frame will
create very harsh winter weather conditions. Headlines for
wind, cold, and snow are likely with later forecast packages.
Further south and east, possibly as far east as the Blue Ridge,
snow showers are expected as well with minor accumulations
possible. With the ground frozen from several days of sub-
freezing temperatures, minor accumulations, perhaps up to 1-2
inches will be possible, especially along the higher elevations
of the Blue Ridge from western Roanoke county through
Floyd/Carroll and Grayson VA. Those planning travel Wednesday
night and Thursday morning should be prepared for harsh winter
weather conditions. Avoid travel if possible during this time
frame.

Temperatures will briefly warm into the 40s Wednesday before the
Arctic cold front arrives by afternoon. Thursday will bring a
non-diurnal temperature trend with temperatures plummeting into
the teens by afternoon/evening west and 20s east. Friday
morning, as the Arctic air mass and the heart of the cold air
settles over the forecast area, temperatures will range from 5
above zero western mountain higher elevations to around 20
across the Piedmont.

/Confidence Levels in Forecast Parameters/
- Moderate to High Confidence in Temperatures,
- Moderate Confidence in Precipitation Probabilities,
- Moderate to High Confidence in Wind Direction and Speed.

&&

.LONG TERM /SATURDAY THROUGH MONDAY/...
As of 400 AM EST Tuesday...

Key Messages:

1). Temperatures moderating into the 40s and 50s over the
weekend.

2). Widespread rain expected by Monday with a pattern change.

Arctic high pressure will drift southeast over the weekend
allowing temperatures to moderate as southwest winds bring
warmer air into the region. A notable southern stream system,
now located over TX, will move east to northeast over the
weekend reaching the southern/central Appalachians by Sunday
into Monday. Enough warming is indicated that other than a brief
period of snow/sleet/freezing rain very early Monday, this next
precipitation event is expected to be primarily rain.

The rain event will come as a slight pattern change aloft is
noted. A split flow pattern appears to be developing with a
distinct southern stream system (currently in TX) and the
continued northern stream dominance into the Mid-Atlantic
region. The various long range models are still at odds with the
precise timing and location of the precipitation late this
weekend, which looks to be largely an overrunning event until
the attendant cold front arrives. Therefore continued the
previous trend of low or slight chance pops until better model
consensus is apparent.

/Confidence Levels in Forecast Parameters/
- Moderate to High Confidence in Temperatures,
- Moderate Confidence in Precipitation Probabilities,
- Moderate Confidence in Wind Direction and Speed.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
As of 240 AM EST Tuesday...

System quickly exits this morning, allowing for high pressure
and VFR clearing this morning along and east of the Blue
Ridge. Residual upslope MVFR in the mountains will gradually
shrink throughout the day. KBLF will be last to improve.

The wind will be out of the northwest today, with some gusts up
to 20 kts possible in the afternoon.

Average confidence for ceiling, visibility, and wind.

EXTENDED AVIATION OUTLOOK...

Primarily VFR conditions are expected in the foothills and
piedmont through Friday.

Wednesday night into Thursday, upslope snow showers and sub-VFR
conditions are expected over parts of southeast West Virginia.
Very gusty northwest winds are expected for all locations
Wednesday night into Thursday, especially across the mountains.

Dry, cold, VFR conditions are expected Thursday night through
Saturday.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

$$

SYNOPSIS...SH
NEAR TERM...SH
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...BMG/SH