Alert archive / North Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 107, NWS Raleigh, NC

August 12, 2021Davidson County, Forsyth County, North Carolina

NWS Raleigh, NC issued this severe thunderstorm warning at Aug 12, 2021, 5:21 PM EDT for Davidson County, Forsyth County, North Carolina. It was in force for 39 min. 2 reports 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, 5:21 PM EDT (21:21 UTC)
Expired
Aug 12, 2021, 6:00 PM EDT
In force
39 min
Issued by
NWS Raleigh, NC
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

Counties Davidson County, NC, Forsyth County, NC

The radar

The Roanoke radar (KFCX), 107 km from the middle of the area, began a volume at 21:21 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, 5:22 PM EDTTSTM WND DMG2 Sw Winston-Salem, NCTREE ON HOUSE. NO INJURIES REPORTED.
Aug 12, 5:32 PM EDTTSTM WND DMG4 Sw Winston-Salem, NCTREE DOWN ON S STRATFORD ROAD.

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

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 9.4 hours before the alert went out and 43 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.

634 
WUUS52 KRAH 122121
SVRRAH
NCC057-067-122200-
/O.NEW.KRAH.SV.W.0107.210812T2121Z-210812T2200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Raleigh NC
521 PM EDT Thu Aug 12 2021

The National Weather Service in Raleigh has issued a

* Severe Thunderstorm Warning for...
  Forsyth County in central North Carolina...
  Northeastern Davidson County in central North Carolina...

* Until 600 PM EDT.

* At 520 PM EDT, a severe thunderstorm was located near
  Winston-Salem, moving northeast at 15 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Winston-Salem, Kernersville, Clemmons, Bermuda Run, Lewisville,
  Walkertown, Rural Hall, Pfafftown, Belews Creek and Arcadia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Hail and damaging winds and continuous cloud to ground lightning is 
occurring with this storm. Move indoors immediately.

Heavy rainfall is occurring with this storm, and may lead to flash 
flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3611 8050 3612 8046 3626 8030 3626 8004
      3599 8005 3589 8037 3596 8038 3599 8042
      3601 8042 3606 8046 3604 8049 3605 8051
TIME...MOT...LOC 2120Z 228DEG 13KT 3614 8028 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CA
1 follow-up statement
514 
WWUS52 KRAH 122142
SVSRAH

Severe Weather Statement
National Weather Service Raleigh NC
542 PM EDT Thu Aug 12 2021

NCC057-067-122200-
/O.CON.KRAH.SV.W.0107.000000T0000Z-210812T2200Z/
Forsyth NC-Davidson NC-
542 PM EDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM EDT
FOR FORSYTH AND NORTHEASTERN DAVIDSON COUNTIES...

At 540 PM EDT, a severe thunderstorm was located over Winston-Salem, 
moving northeast at 10 mph. This storm is producing heavy rainfall.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Winston-Salem, Kernersville, Clemmons, Bermuda Run, Lewisville,
Walkertown, Rural Hall, Pfafftown, Belews Creek and Arcadia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. 

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

&&

LAT...LON 3614 8041 3626 8030 3626 8004 3599 8005
      3589 8037 3596 8038 3599 8042 3607 8042
TIME...MOT...LOC 2140Z 243DEG 8KT 3611 8028 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

CA

The office that day

Everything else NWS Raleigh, NC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 3:30 PM EDTHeat AdvisoryRAHChatham, Cumberland, Durham, Edgecombe, Franklin, Granville and 12 more28 hr
Aug 12, 4:39 PM EDTSpecial Weather StatementRAHFranklin66 min
Aug 12, 4:56 PM EDTSpecial Weather StatementRAHForsyth, Guilford64 min
Aug 12, 5:38 PM EDTAreal Flood AdvisoryRAHForsyth108 min
Aug 12, 5:59 PM EDTSpecial Weather StatementRAHForsyth, Guilford61 min
Aug 12, 6:03 PM EDTSpecial Weather StatementRAHWake57 min
Aug 12, 6:22 PM EDTSpecial Weather StatementRAHDurham38 min
Aug 12, 7:15 PM EDTSpecial Weather StatementRAHMoore45 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.