Alert archive / Virginia / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 152, NWS Blacksburg, VA

August 12, 20215 counties in Virginia

NWS Blacksburg, VA issued this severe thunderstorm warning at Aug 12, 2021, 1:17 PM EDT for 5 counties in Virginia. It was in force for 38 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 12, 2021, 1:17 PM EDT (17:17 UTC)
Expired
Aug 12, 2021, 1:55 PM EDT
In force
38 min
Issued by
NWS Blacksburg, VA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Bedford County, VA, City of Roanoke, VA, City of Salem, VA, Franklin County, VA, Roanoke County, VA

The radar

The Roanoke radar (KFCX), 31 km from the middle of the area, began a volume at 17:18 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.

What was reported inside it

TimeReportWhereRemark
Aug 12, 1:20 PM EDTHAIL 0.253 Ese Glenvar, VAPEA HAIL AND SMALL LIMBS DOWN.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 5.3 hours before the alert went out and 45 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, Roanoke, VA at 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 75 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Roanoke, VA at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 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
75 J/kg
Mixed-layer CIN
-176 J/kg
Mixed-layer LCL
1340 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

145 
WUUS51 KRNK 121717
SVRRNK
VAC019-067-161-770-775-121815-
/O.NEW.KRNK.SV.W.0152.210812T1717Z-210812T1815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service BLACKSBURG VA
117 PM EDT Thu Aug 12 2021

The National Weather Service in BLACKSBURG has issued a

* Severe Thunderstorm Warning for...
  Central Roanoke County in west central Virginia...
  The City of Salem in west central Virginia...
  The City of Roanoke in west central Virginia...
  Western Bedford County in south central Virginia...
  North central Franklin County in west central Virginia...

* Until 215 PM EDT.

* At 117 PM EDT, a severe thunderstorm was located near Poages Mill,
  or near Salem, moving southeast at 15 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Roanoke...
  Salem...
  Vinton...
  Boones Mill...
  Stewartsville...
  Bent Mountain...
  and Glenvar.

This includes The following Locations The Salem Fairgrounds and
Roanoke Regional Airport.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for damaging winds. For your safety, move to an
interior room on the lowest floor of a sturdy building. Stay away
from windows.

When it is safe to do so, please send your reports of hail of any
size, as well as reports of any wind damage, including downed trees
or large limbs, to the National Weather Service by calling toll free
at 1...8 6 6...2 1 5...4 3 2 4. Reports and pictures can also be
shared on the National Weather Service Blacksburg Facebook page and
on Twitter.

&&

LAT...LON 3703 7988 3719 8019 3723 8019 3724 8020
      3735 8010 3733 7992 3728 7972
TIME...MOT...LOC 1717Z 302DEG 11KT 3724 8008 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

ET
2 follow-up statements
841 
WWUS51 KRNK 121742
SVSRNK

Severe Weather Statement
National Weather Service BLACKSBURG VA
142 PM EDT Thu Aug 12 2021

VAC019-067-161-770-775-121815-
/O.CON.KRNK.SV.W.0152.000000T0000Z-210812T1815Z/
Roanoke VA-City of Salem VA-City of Roanoke VA-Bedford VA-
Franklin VA-
142 PM EDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT 
FOR CENTRAL ROANOKE...WESTERN BEDFORD AND NORTH CENTRAL FRANKLIN 
COUNTIES...THE CITY OF SALEM AND THE CITY OF ROANOKE...

At 141 PM EDT, a severe thunderstorm was located over Cave Spring, or
near Roanoke, moving southeast at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Roanoke...
Salem...
Vinton...
Boones Mill...
Stewartsville...
Bent Mountain...
and Poages Mill.

This includes The following Locations The Salem Fairgrounds and
Roanoke Regional Airport.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for DAMAGING WINDS. For your safety, move to an
interior room on the lowest floor of a sturdy building. Stay away
from windows.

When it is safe to do so, please send your reports of hail of any
size, as well as reports of any wind damage, including downed trees
or large limbs, to the National Weather Service by calling toll free
at 1...8 6 6...2 1 5...4 3 2 4. Reports and pictures can also be
shared on the National Weather Service Blacksburg Facebook page and
on Twitter.

&&

LAT...LON 3703 7988 3719 8019 3723 8017 3735 8010
      3733 7992 3728 7972
TIME...MOT...LOC 1741Z 302DEG 11KT 3720 8000 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

ET
721 
WWUS51 KRNK 121755
SVSRNK

Severe Weather Statement
National Weather Service BLACKSBURG VA
155 PM EDT Thu Aug 12 2021

VAC019-067-161-770-775-121804-
/O.CAN.KRNK.SV.W.0152.000000T0000Z-210812T1815Z/
Roanoke VA-City of Salem VA-City of Roanoke VA-Bedford VA-
Franklin VA-
155 PM EDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR 
CENTRAL ROANOKE...WESTERN BEDFORD AND NORTH CENTRAL FRANKLIN
COUNTIES...THE CITY OF SALEM AND THE CITY OF ROANOKE IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and 
heavy rain are still possible with multiple thunderstorms in the 
area. 

LAT...LON 3703 7988 3719 8019 3723 8017 3735 8010
      3733 7992 3728 7972
TIME...MOT...LOC 1752Z 302DEG 11KT 3718 7995 

$$

ET

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 9:54 AM EDTHeat AdvisoryRNKBuckingham9 hr
Aug 12, 12:28 PM EDTSpecial Weather StatementRNKGrayson32 min
Aug 12, 1:04 PM EDTSpecial Weather StatementRNKRoanoke, City of Roanoke, City of Salem26 min
Aug 12, 1:30 PM EDTSpecial Weather StatementRNKAlleghany30 min
Aug 12, 2:03 PM EDTSpecial Weather StatementRNKCity of Roanoke27 min
Aug 12, 2:09 PM EDTSpecial Weather StatementRNKPittsylvania36 min
Aug 12, 2:12 PM EDTSevere Thunderstorm WarningRNKBedford, Campbell, Franklin, Pittsylvania, Roanoke63 min
Aug 12, 2:15 PM EDTSpecial Weather StatementRNKAlleghany, City of Covington30 min
Aug 12, 2:24 PM EDTSpecial Weather StatementRNKHenry36 min
Aug 12, 2:57 PM EDTSevere Thunderstorm WarningRNKHenry, Patrick51 min
Aug 12, 3:18 PM EDTSevere Thunderstorm WarningRNKFranklin29 min
Aug 12, 3:27 PM EDTSevere Thunderstorm WarningRNKCarroll, Wythe48 min
Aug 12, 3:34 PM EDTSpecial Weather StatementRNKCity of Lexington26 min
Aug 12, 3:37 PM EDTSevere Thunderstorm WarningRNKCraig, Montgomery, Roanoke53 min
Aug 12, 3:43 PM EDTSevere Thunderstorm WarningRNKFranklin32 min
Aug 12, 3:51 PM EDTSpecial Weather StatementRNKPatrick24 min
Aug 12, 3:58 PM EDTSevere Thunderstorm WarningRNKPatrick47 min
Aug 12, 4:14 PM EDTSpecial Weather StatementRNKCity of Salem31 min
Aug 12, 4:14 PM EDTSpecial Weather StatementRNKCity of Salem31 min
Aug 12, 4:16 PM EDTSevere Thunderstorm WarningRNKFloyd, Patrick29 min
Aug 12, 4:20 PM EDTSevere Thunderstorm WarningRNKFranklin, Roanoke27 min
Aug 12, 4:24 PM EDTSpecial Weather StatementRNKFloyd36 min
Aug 12, 4:26 PM EDTSpecial Weather StatementRNKGrayson34 min
Aug 12, 4:44 PM EDTSpecial Weather StatementRNKCity of Danville31 min
Aug 12, 4:49 PM EDTSevere Thunderstorm WarningRNKFloyd, Franklin, Patrick35 min
Aug 12, 7:42 PM EDTHeat AdvisoryRNKAppomattox, Buckingham, Campbell, Charlotte, City of Lynchburg23 hr

Nearby

Severe Thunderstorm Warnings in Virginia, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.