Alert archive / North Carolina / Special Weather Statements in 2021

Special Weather Statement, NWS Blacksburg, VA

July 9, 2021Stokes County, North Carolina

NWS Blacksburg, VA issued this special weather statement at Jul 9, 2021, 1:40 PM EDT for Stokes County, North Carolina. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 9, 2021, 1:40 PM EDT (17:40 UTC)
Expired
Jul 9, 2021, 2:15 PM EDT
In force
35 min
Issued by
NWS Blacksburg, VA

County Stokes County, NC

The radar

The Roanoke radar (KFCX), 85 km from the middle of the area, began a volume at 17:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 5.7 hours before the alert went out and 55 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2021-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 127 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2021-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
127 J/kg
Mixed-layer CIN
-97 J/kg
Mixed-layer LCL
1287 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Blacksburg, VA wrote its last area forecast discussion before this special weather statement went out at Jul 9, 9:00 AM EDT, 4 hours 40 minutes earlier.

Area forecast discussion, Jul 9, 9:00 AM EDT, 4 hours 40 minutes before
Area Forecast Discussion
National Weather Service Blacksburg VA
900 AM EDT Fri Jul 9 2021

.SYNOPSIS...
A front crosses the area today and tonight with scattered
storms, then meanders nearby into Sunday, keeping daily storm
chances in the region. High pressure and warmer temperatures
build in for Tuesday and Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 845 AM EDT Friday...

Cluster of showers and thunderstorms are moving rapidly through
southern WV and east into VA this morning. Have expanded and
increased PoPs and QPF where rain is imminent and also
increased coverage of thunder. Showers without thunder are still
more likely east of the Blue Ridge through 11 AM. Rainfall is
heavy from Tazewell to Bland and into Mercer and Giles Counties,
but is thankfully shifting east quickly. These areas will see a
quick half inch or more, and currently instantaneous rain rates
are around 3-5 in/hr.

As of 310 AM EDT Friday...

 Trimmed probability of precipitation tonight...

Pre-frontal trough from eastern Ohio to western Tennessee moves east
today, reaching the West Virginia/Virginia border around 08Z/4AM and
advancing east of Lynchburg, Danville, and Reidsville around
21z/5PM. 3km NAM was developing a broken line of thunderstorms
along this feature after noon. The weak front crosses the region
this evening. Already have some instability ahead of the trough
which maximizes over the piedmont by mid afternoon. One
drawback for this afternoon will be the overall westerly
downslope component of the winds, which may suppress the
coverage of showers and thunderstorms until the pre-frontal
trough is farther east.

Drier air comes in behind the front for tonight. Clouds clear out in
the evening with the exception of the far western upslope areas.
Temperatures not much different in the post-frontal air mass
but surface dew points drop into the 50s late tonight.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
As of 300 AM EDT Friday...

 After a dry start to Saturday, a warm front will bring more
 showers and thunderstorms for the remainder of the weekend.

Weak high pressure will pass to the north on Saturday morning, but
it will give way to a warm front moving eastward from the Ohio River
Valley by Saturday night. There should be lingering dry air on
Saturday that could delay any development of showers and
thunderstorms until the evening. Moisture will return during
Saturday night into Sunday as the warm front lifts northward due to
its progress eastward being stopped by a retrograding upper level
ridge over the Atlantic Ocean. Confidence is highest for convection
on Sunday based on the coverage and the consistency portrayed in the
models. CAPE is also most sufficient during Sunday afternoon.

The upper level ridge will continue to propagate westward over
eastern Virginia and North Carolina during Sunday night into Monday.
With the ECMWF and the GFS models both showing the ridge building up
to 598 dam at 500 mb, a notable capping inversion aloft could start
to suppress any development of convection across the Piedmont. There
will still be a decent chance of showers and thunderstorms west of
the Blue Ridge on Monday afternoon, but the coverage should be more
isolated than what will occur on Sunday due to the increasing
influence of the ridge. It will also start to feel more hot and
humid, and nights will become increasingly muggy.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
As of 300 AM EDT Friday...

 Hot and humid weather will persist throughout this period with
 a chance of showers and thunderstorms in the mountains.

With the upper level ridge reaching its closest proximity to the Mid
Atlantic on Tuesday, it will continue to block an upper level trough
over the central Mississippi River Valley from advancing eastward.
Thus, rainfall chances appear limited with only isolated showers and
thunderstorms west of the Blue Ridge during Tuesday afternoon. The
ridge should buckle and weaken by Tuesday night into Wednesday,
which will allow the upper level trough to move eastward over the
Great Lakes. More troughing appears likely across southeastern
Canada by Thursday based on the latest model solutions. As a result,
chances of showers and thunderstorms will tick back upward during
the latter half of this week.

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
As of 900 AM EDT Friday...

Cold front from the Ohio Valley to the Mid Mississippi Valley
will move southeast today across the Mid Atlantic region.
Southwest winds ahead of the front will become west by this
afternoon then northwest behind the front tonight. Some wind
gusts up to 20 knots are possible this afternoon. Wind speeds
diminish across the area after sunset.

Ahead of the front this morning, TSRA will bring MVFR/brief LIFR
in heavy rain, spreading east of the BLue Ridge by noon.
Scattered showers and thunderstorms will redevelop along the
pre- frontal trough this afternoon, mainly east of Blue Ridge.
Hi-res guidance has a majority of the thunderstorms east of
KLYH and KDAN by 00Z/8PM.

Have added LIFR fog in for KLWB late tonight after clouds clear
out.

Average confidence for wind, ceilings and visibility.

Extended Aviation Discussion...

There may be a bit of a break in shower and storm activity on
Saturday, although not zero chances, and then as moisture
increases again on back side of surface ridge of high pressure
and ahead of the next slowly approaching frontal system.

Afternoon and evening shower and storm chances increase each
day from Sunday into Monday. Patchy morning fog in the valleys
will be possible each day as well.

Tuesday is looking a day with limited thunderstorms, which will
be confined to the mountains.

&&

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

&&

SYNOPSIS...AMS
NEAR TERM...AMS/SH
SHORT TERM...PW
LONG TERM...PW
AVIATION...AMS/SK/SH
Hazardous weather outlook, Jul 9, 5:10 AM EDT, 8 hours 30 minutes before
Hazardous Weather Outlook
National Weather Service Blacksburg VA
510 AM EDT Fri Jul 9 2021

NCZ001>004-018>020-VAZ007-009>020-022>024-032>035-043-WVZ042>044-507-
508-100915-
Ashe-Alleghany NC-Surry-Stokes-Watauga-Wilkes-Yadkin-Tazewell-Smyth-
Bland-Giles-Wythe-Pulaski-Montgomery-Grayson-Carroll-Floyd-Craig-
Alleghany VA-Bath-Roanoke-Botetourt-Rockbridge-Patrick-Franklin-
Bedford-Amherst-Henry-Mercer-Summers-Monroe-Eastern Greenbrier-
Western Greenbrier-
510 AM EDT Fri Jul 9 2021

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

.DAY ONE...Today and tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

There is a marginal risk of severe thunderstorms during Sunday
afternoon. The primary threat is damaging winds.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

NCZ005-006-VAZ044>047-058-059-100915-
Rockingham-Caswell-Pittsylvania-Campbell-Appomattox-Buckingham-
Halifax-Charlotte-
510 AM EDT Fri Jul 9 2021

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

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PW

In the hours before

Special weather statement, Jul 9, 9:17 AM EDT, 4 hours 23 minutes before
Special Weather Statement
National Weather Service BLACKSBURG VA
917 AM EDT Fri Jul 9 2021

VAZ010-011-WVZ042>044-091345-
Giles-Bland-Mercer-Summers-Monroe-
917 AM EDT Fri Jul 9 2021

...A STRONG THUNDERSTORM WILL AFFECT WESTERN GILES...NORTH CENTRAL
BLAND...SOUTH CENTRAL SUMMERS...SOUTHEASTERN MERCER AND SOUTHWESTERN
MONROE COUNTIES...

At 916 AM EDT, a strong thunderstorm was located over Oakvale, or
near Athens, moving east at 35 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Princeton...
Pearisburg...
Narrows...
Athens...
Peterstown...
Poplar Hill...
and Rich Creek.

Locally heavy rain, with rates of two to four inches per hour, 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.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 3725 8110 3748 8108 3750 8069 3722 8070
TIME...MOT...LOC 1316Z 270DEG 32KT 3737 8097

DS
Special weather statement, Jul 9, 12:50 PM EDT, 50 minutes before
Special Weather Statement
National Weather Service BLACKSBURG VA
1250 PM EDT Fri Jul 9 2021

NCZ003-004-VAZ032-091715-
Stokes-Surry-Patrick-
1250 PM EDT Fri Jul 9 2021

...A STRONG THUNDERSTORM WILL AFFECT
NORTHEASTERN SURRY...NORTHWESTERN STOKES AND SOUTH CENTRAL PATRICK
COUNTIES...

At 1250 PM EDT, a strong thunderstorm was located over Toast, or over
Mount Airy, moving east at 25 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Mount Airy...
Flat Rock...
Pilot Mountain...
Francisco...
Woodville...
White Plains...
and Ararat.

LAT...LON 3641 8071 3650 8072 3663 8031 3636 8028
TIME...MOT...LOC 1650Z 264DEG 21KT 3647 8063

RR
Special weather statement, Jul 9, 1:40 PM EDT, 0 minutes before
Special Weather Statement
National Weather Service BLACKSBURG VA
140 PM EDT Fri Jul 9 2021

NCZ003-004-020-091815-
Stokes-Yadkin-Surry-
140 PM EDT Fri Jul 9 2021

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT
SOUTHEASTERN SURRY...SOUTHERN STOKES AND NORTHEASTERN YADKIN
COUNTIES...

At 139 PM EDT, strong thunderstorms were clustered near Pilot
Mountain State Park, or near Pilot Mountain, moving east at 25 mph.

Winds in excess of 30 mph are possible with this storm.

Locations impacted include...
Pilot Mountain...
Walnut Cove...
Boonville...
East Bend...
Danbury...
King...
and Level Cross.

LAT...LON 3624 8074 3641 8065 3647 8011 3626 8012
      3626 8045 3624 8045 3622 8043 3621 8045
      3619 8044
TIME...MOT...LOC 1739Z 270DEG 23KT 3634 8047

RR

The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 9, 9:15 AM EDTAreal Flood AdvisoryRNKTazewell3 hr
Jul 9, 9:17 AM EDTSpecial Weather StatementRNKGiles28 min
Jul 9, 4:52 PM EDTSpecial Weather StatementRNKHalifax23 min
Jul 9, 12:50 PM EDTSpecial Weather StatementRNKSurry25 min
Jul 9, 3:41 PM EDTSpecial Weather StatementRNKPerson34 min
Jul 9, 5:40 PM EDTSevere Thunderstorm WarningRNKStokes, Surry, Yadkin50 min

Nearby

Special Weather Statements in North Carolina, 2021Every special weather statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.