Alert archive / North Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 153, NWS Blacksburg, VA

August 12, 20214 counties in North Carolina

NWS Blacksburg, VA issued this severe thunderstorm warning at Aug 12, 2021, 1:35 PM EDT for 4 counties in North Carolina. It was in force for 55 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
Aug 12, 2021, 1:35 PM EDT (17:35 UTC)
Expired
Aug 12, 2021, 2:30 PM EDT
In force
55 min
Issued by
NWS Blacksburg, VA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Alleghany County, NC, Surry County, NC, Wilkes County, NC, Yadkin County, NC

The radar

The Roanoke radar (KFCX), 117 km from the middle of the area, began a volume at 17:39 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, 5.6 hours before the alert went out and 109 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 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1015 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, Greensboro/Hi Pt, NC at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -42 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
1015 J/kg
Mixed-layer CIN
-92 J/kg
Mixed-layer LCL
1048 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-42 m²/s²
0-3 km storm-relative helicity
-15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

816 
WUUS51 KRNK 121735
SVRRNK
NCC005-171-193-197-121830-
/O.NEW.KRNK.SV.W.0153.210812T1735Z-210812T1830Z/

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

The National Weather Service in BLACKSBURG has issued a

* Severe Thunderstorm Warning for...
  Southeastern Alleghany County in northwestern North Carolina...
  Southwestern Surry County in northwestern North Carolina...
  Wilkes County in northwestern North Carolina...
  Northwestern Yadkin County in northwestern North Carolina...

* Until 230 PM EDT.

* At 135 PM EDT, a severe thunderstorm was located near Dockery, or
  near Mc Grady, moving southeast at 15 mph.

  HAZARD...60 mph wind gusts and pea size hail.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  North Wilkesboro...
  Elkin...
  Wilkesboro...
  Jonesville...
  Ronda...
  Traphill...
  and Mc Grady.

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.

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 3604 8113 3636 8135 3637 8131 3636 8128
      3636 8125 3639 8124 3647 8094 3613 8074
      3605 8091 3606 8098 3604 8104 3603 8106
TIME...MOT...LOC 1735Z 332DEG 15KT 3630 8114 

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

$$

ET
1 follow-up statement
773 
WWUS51 KRNK 121759
SVSRNK

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

NCC197-121808-
/O.CAN.KRNK.SV.W.0153.000000T0000Z-210812T1830Z/
Yadkin NC-
159 PM EDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR 
NORTHWESTERN YADKIN COUNTY IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3636 8134 3637 8131 3636 8128 3636 8125
      3639 8124 3647 8094 3625 8081 3624 8087
      3621 8088 3612 8119
TIME...MOT...LOC 1758Z 351DEG 4KT 3631 8116 

$$

NCC005-171-193-121830-
/O.CON.KRNK.SV.W.0153.000000T0000Z-210812T1830Z/
Alleghany NC-Surry NC-Wilkes NC-
159 PM EDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 PM EDT
FOR
SOUTHEASTERN ALLEGHANY...SOUTHWESTERN SURRY AND NORTHEASTERN WILKES
COUNTIES IN NORTHWESTERN NORTH CAROLINA...

At 158 PM EDT, a severe thunderstorm was located near Halls Mills, or
near Mc Grady, and is nearly stationary.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
North Wilkesboro...
Elkin...
Wilkesboro...
Ronda...
Traphill...
Mc Grady...
and Mulberry.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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.

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 3636 8134 3637 8131 3636 8128 3636 8125
      3639 8124 3647 8094 3625 8081 3624 8087
      3621 8088 3612 8119
TIME...MOT...LOC 1758Z 351DEG 4KT 3631 8116 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

ET

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 12:57 PM EDTSpecial Weather StatementRNKAlleghany33 min
Aug 12, 1:22 PM EDTSpecial Weather StatementRNKWilkes23 min
Aug 12, 1:45 PM EDTSpecial Weather StatementRNKWatauga30 min
Aug 12, 2:18 PM EDTSevere Thunderstorm WarningRNKAlleghany, Ashe, Surry, Watauga, Wilkes, Yadkin57 min
Aug 12, 2:27 PM EDTAreal Flood AdvisoryRNKAlleghany, Ashe, Surry, Watauga, Wilkes3 hr
Aug 12, 2:57 PM EDTSevere Thunderstorm WarningRNKRockingham, Stokes51 min
Aug 12, 3:11 PM EDTSevere Thunderstorm WarningRNKAlleghany, Ashe, Watauga, Wilkes53 min
Aug 12, 3:24 PM EDTSpecial Weather StatementRNKSurry36 min
Aug 12, 3:31 PM EDTSevere Thunderstorm WarningRNKStokes, Surry14 min
Aug 12, 3:46 PM EDTSpecial Weather StatementRNKAshe29 min
Aug 12, 3:53 PM EDTSpecial Weather StatementRNKRockingham37 min
Aug 12, 3:58 PM EDTSevere Thunderstorm WarningRNKStokes, Surry47 min
Aug 12, 4:03 PM EDTAreal Flood AdvisoryRNKAshe, Wilkes3 hr
Aug 12, 4:27 PM EDTSevere Thunderstorm WarningRNKYadkin37 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.