Alert archive / North Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 138, NWS Raleigh, NC

December 11, 2021Alamance County, Orange County, North Carolina

NWS Raleigh, NC issued this severe thunderstorm warning at Dec 11, 2021, 6:44 PM EST for Alamance County, Orange County, North Carolina. It was in force for 46 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: Dec 11, 2021, 6:44 PM EST (23:44 UTC)
Expired: Dec 11, 2021, 7:30 PM EST
In force: 46 min
Issued by: NWS Raleigh, NC
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Alamance County, NC, Orange County, NC

The radar

The Raleigh/Durham radar (KRAX), 85 km from the middle of the area, began a volume at 23:44 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

Time	Report	Where	Remark
Dec 11, 6:47 PM EST	TSTM WND DMG	3 W Schley, NC	TREE DOWN ON WALNUT GROVE CHURCH RD.

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, 11.7 hours before the alert went out and 65 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 481 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 284 m²/s²
0-3 km storm-relative helicity: 258 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

271 
WUUS52 KRAH 112344
SVRRAH
NCC001-135-120030-
/O.NEW.KRAH.SV.W.0138.211211T2344Z-211212T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Raleigh NC
644 PM EST Sat Dec 11 2021

The National Weather Service in Raleigh has issued a

* Severe Thunderstorm Warning for...
  Northern Alamance County in central North Carolina...
  Northern Orange County in central North Carolina...

* Until 730 PM EST.

* At 642 PM EST, a severe thunderstorm was located near Mebane, or 7
  miles northeast of Graham, moving east at 40 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Burlington, Graham, Mebane, Elon, Gibsonville, Haw River, Carr,
  Lake Burlington, Schley and Lake Cammack Park & Marina.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Straight line winds can blow down trees, power lines, and damage
mobile homes and other buildings. Seek shelter in a sturdy structure
until the storm has passed. Stay away from windows as flying debris
generated by damaging winds can be deadly.

&&

LAT...LON 3624 7895 3612 7897 3605 7954 3625 7953
TIME...MOT...LOC 2342Z 257DEG 35KT 3615 7930 

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

$$

CA

2 follow-up statements

460 
WWUS52 KRAH 120009
SVSRAH

Severe Weather Statement
National Weather Service Raleigh NC
709 PM EST Sat Dec 11 2021

NCC001-120018-
/O.CAN.KRAH.SV.W.0138.000000T0000Z-211212T0030Z/
Alamance NC-
709 PM EST Sat Dec 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN ALAMANCE 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 3624 7895 3612 7897 3610 7911 3624 7912
TIME...MOT...LOC 0008Z 256DEG 34KT 3617 7903 

$$

NCC135-120030-
/O.CON.KRAH.SV.W.0138.000000T0000Z-211212T0030Z/
Orange NC-
709 PM EST Sat Dec 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM EST
FOR NORTHEASTERN ORANGE COUNTY...

At 708 PM EST, a severe thunderstorm was located near Rougemont, or 7
miles northeast of Hillsborough, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Schley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Straight line winds can blow down trees, power lines, and damage
mobile homes and other buildings. Seek shelter in a sturdy structure
until the storm has passed. Stay away from windows as flying debris
generated by damaging winds can be deadly.

&&

LAT...LON 3624 7895 3612 7897 3610 7911 3624 7912
TIME...MOT...LOC 0008Z 256DEG 34KT 3617 7903 

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

$$

Green

994 
WWUS52 KRAH 120022
SVSRAH

Severe Weather Statement
National Weather Service Raleigh NC
722 PM EST Sat Dec 11 2021

NCC135-120031-
/O.EXP.KRAH.SV.W.0138.000000T0000Z-211212T0030Z/
Orange NC-
722 PM EST Sat Dec 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ORANGE COUNTY
WILL EXPIRE AT 730 PM EST...
                
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 will be allowed to expire.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Raleigh.

LAT...LON 3624 7895 3612 7897 3610 7911 3624 7912
TIME...MOT...LOC 0021Z 257DEG 35KT 3620 7889 

$$

Green

The office that day

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

Issued	Product	Office	Counties	Lasted
Dec 11, 3:58 PM EST	Special Weather Statement	RAH	Forsyth	47 min
Dec 11, 4:36 PM EST	Special Weather Statement	RAH	Davidson, Randolph	39 min
Dec 11, 4:52 PM EST	Special Weather Statement	RAH	Forsyth, Guilford	53 min
Dec 11, 5:19 PM EST	Special Weather Statement	RAH	Alamance, Davidson, Guilford, Randolph	56 min
Dec 11, 5:24 PM EST	Special Weather Statement	RAH	Montgomery, Stanly	36 min
Dec 11, 5:27 PM EST	Special Weather Statement	RAH	Montgomery, Stanly	33 min
Dec 11, 5:54 PM EST	Severe Thunderstorm Warning	RAH	Davidson, Guilford, Randolph	36 min
Dec 11, 5:56 PM EST	Special Weather Statement	RAH	Anson, Montgomery, Richmond, Stanly	34 min
Dec 11, 6:05 PM EST	Severe Thunderstorm Warning	RAH	Alamance, Guilford	40 min
Dec 11, 6:13 PM EST	Severe Thunderstorm Warning	RAH	Anson, Chatham, Lee, Montgomery, Moore, Randolph and 1 more	47 min
Dec 11, 6:15 PM EST	Special Weather Statement	RAH	Granville, Person, Vance	45 min
Dec 11, 6:30 PM EST	Severe Thunderstorm Warning	RAH	Alamance, Chatham, Guilford, Orange, Randolph	45 min
Dec 11, 6:59 PM EST	Special Weather Statement	RAH	Franklin, Granville, Vance, Warren	61 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2021 Every 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.