Special Weather Statement, NWS Blacksburg, VA

Area Forecast Discussion
National Weather Service Blacksburg VA
229 PM EDT Mon Oct 25 2021

.SYNOPSIS...
A strong cold front will cross the area tonight, preceded by
showers and thunderstorms. Storms this evening could be severe.
After the passage of the front tonight expect much cooler
weather with strong gusty winds for Tuesday. High pressure will
pass across the region Wednesday, winds diminishing. Another
storm system will bring widespread rainfall for the end of the
week.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 225 PM EDT Monday...

There is a slight risk for severe storms mainly along and east
of the Blue Ridge this evening. Damaging thunderstorm wind
gusts and isolated tornadoes are possible.

All eyes are focused on the dynamic upper level shortwave
trough spinning across the northern Ohio Valley this afternoon,
as well as the accompanying cold front trailing south into
central KY. There is a prefrontal band of showers and cloud
cover (remnants of last nights storms) racing east and ahead of
the actual surface front. This prefrontal band of showers was
running up against the windward slopes of the Appalachians and
will move across our western CWA this afternoon. Additional
shower/storm activity was percolating over eastern NC per
development of a coastal low just off the Mid-Atlantic coast.

Forecast is for the parent short wave trough over the Ohio
Valley to continue to move east toward the central/northern
Appalachians this afternoon and evening with height falls and
the exit region of a strong mid/upper jet overspreading the
southern Appalachians and Carolinas/Virginia. The aforementioned
pre-frontal band of showers and related cloud cover will tend
to hinder pre-frontal destabilization across our mountain
counties with the CWA (esp windward side of the Appalachians),
but a few strong/severe low-topped storms could occur pending
weak but sufficient destabilization during the afternoon in
those areas.

East of the Appalachian Divide and especially across our
piedmont counties, a more certain/probable severe-weather risk
is expected, perhaps initially near/just east of the Blue Ridge
then translating across the piedmont during the late afternoon
and evening. Where there is sun, expect modest destabilization,
with upwards of 1000 J/kg MLCAPE. Strong deep-layer shear will
support some well-organized storms including linear bands aside
from the possibility of some initial/embedded supercells,
particularly across the Piedmont of Virginia and northern North
Carolina. It is this particular area (a line from LYH-GSO and
areas to the east) where bulk shear values and storm relative
helicity supports a relatively greater threat of tornadic
supercells. What is interesting to see in some of the short
range guidance is the formation of a meso-low or lee-side low
vcnty of GSO, this feature moving northeast toward the VA/NC
border just southeast of Danville this evening...winds backing
in the low levels in the vicinity of this feature. Of note, this
is a climatologically favored area for low level cyclogenesis,
a tornado alley of sorts on a local scale. That said, yes this
is a a favored zone to watch, but do not ignore the larger
scale scope. This is a robust system and shear profiles and
strong winds aloft support damaging winds with any storm that
develops this afternoon, regardless of whether it is spinning or
not. Line segments, even with the pre-frontal convection and
even with the cold front tonight, will have the potential for
damaging wind gusts.

Timing is still the same as previously forecast...with activity
impacting the western CWA this afternoon, then translating to
the piedmont during the late afternoon and evening. Once the
prefrontal activity plays out this evening, expect a lull before
the actual arrival of the cold front. The cold front is
expected to sweep across the area during the overnight with
winds increasing and becoming quite gusty attms late tonight and
during the day tomorrow. By then, upper level energy from the
Ohio valley is expected to transfer to the coastal low, the
coastal low becoming the primary focus as we transition through
the day Tuesday. Strong Northwest winds are expected Tuesday as
the coastal storm deepens off the coast with winds aloft
increasing to near 50 kts at 850 MB. This suggests surface wind
gusts of 30 to 45 mph will be possible across our forecast area
for late tonight and Tuesday. Ridge top wind gusts of up to 50
mph are possible for our highest elevations. A wind advisory may
be needed for parts of the forecast area for Tuesday.

Today will be the warmest day of the week with highs in the
70s. Cold air advection behind tonight's FROPA will result in a
much cooler day Tuesday with highs in the 40s/50s mountains and
60s piedmont.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 1100 AM EDT Monday...

High pressure will build overhead on Wednesday, but a closed
upper level low should bring noteworthy rain during Thursday.

With low pressure moving offshore on Tuesday night and high pressure
building from the Great Lakes, the resulting pressure gradient
should continue the gusty northwest winds overnight. Upslope showers
and sprinkles may take most of the night to dissipate across parts
of southeast West Virginia. Once high pressure settles overhead by
late Wednesday, it should allow quieter conditions before things
turn unsettled again later in the week.

A deep upper level low should develop over the central Mississippi
River Valley by Wednesday night, and it will cut off from the jet
stream while wobbling eastward toward Kentucky and Tennessee on
Thursday. Moisture should stream from the Gulf of Mexico and the
Atlantic Ocean in a favorable southeast flow that will result in
noteworthy rain. Confidence is very high that Thursday afternoon
through Thursday night will be wet with QPF reaching one to two
inches, and locally higher amounts are certainly possible due to the
upslope flow along the Blue Ridge. It is too soon to tell how much
of a flooding risk exists, but it shall be monitored with future
model data.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
As of 1100 AM EDT Monday...

A closed upper level low will linger through the weekend but
eventually exit by Monday as high pressure arrives.

Rain will continue into Friday although the models are hinting at
the moisture lessening across North Carolina with the flow turning
more toward the south and southwest to eliminate the upslope flow
over the Blue Ridge. The closed upper level low responsible for this
unsettled weather will slowly move toward the northeast this weekend
as it tries to rejoin the jet stream over southeastern Canada.
However, clouds and showers may persist along and west of the Blue
Ridge during Saturday before eventually fading by Sunday. Winds
could become breezy from the northwest late in the weekend as high
pressure builds eastward from the Plains to provide a quiet Monday.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
As of 215 PM EDT Monday...

Deteriorating flying conditions likely this afternoon and
evening as a strong cold front approaches the region.

A potent cold front will move through our area tonight. In
advance of this feature, clusters of strong to severe
thunderstorms are expected mainly between 18Z (2 PM EDT) and 02Z
(10 PM EDT)...especially for KDAN and KLYH and perhaps KROA.
MVFR cigs and winds gusting over 30kts are possible within the
storms. For KLWB, KBLF, and KBCB showers are likely through the
afternoon with a possibility of thunder and gusty winds within
the precipitation along with temporary sub-VFR cigs.

Once these storms pass, there may be brief return to VFR
conditions, before blustery northwest winds and IFR cigs arrive
across the mountains behind the front at KBLF, KLWB and KBCB
after 05Z.

Extended Aviation Discussion...

Sub-VFR conditions likely linger into Tuesday. Winds on Tuesday
are expected to remain very gusty from the northwest,
VFR conditions return later on Tuesday, lasting through
Wednesday. Another strong system approaches late this week,
bringing another round of rainfall and sub-VFR conditions. Drier
conditions may arrive Saturday into Sunday.

&&

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

&&

SYNOPSIS...PH
NEAR TERM...PM
SHORT TERM...PW
LONG TERM...PW
AVIATION...PM

Hazardous Weather Outlook
National Weather Service Blacksburg VA
448 AM EDT Mon Oct 25 2021

NCZ003>006-019-020-VAZ032>035-043>047-058-059-260900-
Surry-Stokes-Rockingham-Caswell-Wilkes-Yadkin-Patrick-Franklin-
Bedford-Amherst-Henry-Pittsylvania-Campbell-Appomattox-Buckingham-
Halifax-Charlotte-
448 AM EDT Mon Oct 25 2021

This Hazardous Weather Outlook is for north central North Carolina,
northwest North Carolina, central Virginia, south central Virginia,
southwest Virginia and west central Virginia.

.DAY ONE...Today and tonight.

There is slight risk of severe thunderstorms this afternoon and
evening. The main threat from any severe storms will be damaging wind
gusts. There is a smaller threat for an isolated tornado.
Clusters of thunderstorms are expected to move west to east across
the area, mainly between 2PM and 10PM, and will be the most intense
east of Route 29.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Widespread rain is expected Thursday through Friday. The rain will be
heavy at times, especially on Thursday night, which may result in
flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed. Reports should be
submitted by calling 1-866-215-4324, social media, email at
rnk.skywarn@noaa.gov or online at www.weather.gov/rnk.

NCZ001-002-018-VAZ007-009>020-022>024-WVZ042>044-507-508-260900-
Ashe-Alleghany NC-Watauga-Tazewell-Smyth-Bland-Giles-Wythe-Pulaski-
Montgomery-Grayson-Carroll-Floyd-Craig-Alleghany VA-Bath-Roanoke-
Botetourt-Rockbridge-Mercer-Summers-Monroe-Eastern Greenbrier-
Western Greenbrier-
448 AM EDT Mon Oct 25 2021

This Hazardous Weather Outlook is for northwest North Carolina,
southwest Virginia, west central Virginia and southeast West
Virginia.

.DAY ONE...Today and tonight.

There is slight risk of severe thunderstorms this afternoon and
evening. The main threat from any severe storms will be damaging wind
gusts. There is a smaller threat for an isolated tornado.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Widespread rain is expected Thursday through Friday. Locally heavy
rainfall amounts may result in flooding.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Reports should be submitted by
phone by calling 1-866-215-4324, social media, by email at
rnk.skywarn@noaa.gov or online at www.weather.gov/rnk.

Special Weather Statement
National Weather Service BLACKSBURG VA
500 PM EDT Mon Oct 25 2021

VAZ035-045-046-252130-
Amherst VA-Campbell VA-Appomattox VA-
500 PM EDT Mon Oct 25 2021

...A strong thunderstorm will impact portions of
northwestern Appomattox, northeastern Campbell, and southeastern
Amherst Counties and the City of Lynchburg through 530 PM EDT...

At 458 PM EDT, Doppler radar was tracking a strong thunderstorm over
Bocock, or near Rustburg, moving northeast at 30 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Lynchburg...
Amherst...
Bent Creek...
Concord...
Rustburg...
Madison Heights...
and Stonewall.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3721 7906 3732 7924 3764 7912 3756 7891
      3754 7890 3755 7888 3754 7887 3754 7883
      3752 7878 3747 7872
TIME...MOT...LOC 2058Z 219DEG 28KT 3733 7910

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

KK

Special Weather Statement
National Weather Service BLACKSBURG VA
502 PM EDT Mon Oct 25 2021

VAZ024-252130-
Rockbridge VA-
502 PM EDT Mon Oct 25 2021

...A strong thunderstorm will impact portions of Rockbridge County
and the City of Lexington through 530 PM EDT...

At 501 PM EDT, Doppler radar was tracking a strong thunderstorm over
Collierstown, moving northeast at 30 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Lexington...
Goshen...
Collierstown...
Rockbridge Baths...
Bells Valley...
Fairfield...
and Brownsburg.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Locally heavy rain will quickly reduce visibility and result in
ponding of water on roadways, standing water in low lying areas, and
minor flooding of creeks, streams, and areas of poor drainage.
Drivers are urged to slow down and use extra caution to avoid
hydroplaning.

&&

LAT...LON 3793 7921 3763 7961 3768 7967 3769 7967
      3771 7968 3774 7969 3781 7965 3783 7962
      3786 7961 3787 7963 3808 7947
TIME...MOT...LOC 2101Z 219DEG 28KT 3776 7964

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

KK