Alert archive / North Carolina / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 57, NWS Greenville-Spartanburg, SC

June 21, 2021Graham County, Swain County, North Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Jun 21, 2021, 7:31 PM EDT for Graham County, Swain County, North Carolina. It was in force for 44 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: Jun 21, 2021, 7:31 PM EDT (23:31 UTC)
Expired: Jun 21, 2021, 8:15 PM EDT
In force: 44 min
Issued by: NWS Greenville-Spartanburg, SC
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Graham County, NC, Swain County, NC

The radar

The Knoxville radar (KMRX), 87 km from the middle of the area, began a volume at 23:32 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
Jun 21, 7:40 PM EDT	TSTM WND DMG	11 Ne Fontana Village, NC	COUNTY DISPATCH CONFIRMED MULTIPLE TREES AND POWERLINES DOWN ACROSS PARTS OF SWAIN COUNTY.

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

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 11.5 hours before the alert went out and 240 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: 719 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 773 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -3 m²/s²
0-3 km storm-relative helicity: -1 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

768 
WUUS52 KGSP 212331
SVRGSP
NCC075-173-220015-
/O.NEW.KGSP.SV.W.0057.210621T2331Z-210622T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Greenville-Spartanburg SC
731 PM EDT Mon Jun 21 2021

The National Weather Service in Greenville-Spartanburg has issued a

* Severe Thunderstorm Warning for...
  Central Swain County in western North Carolina...
  Graham County in western North Carolina...

* Until 815 PM EDT.

* At 729 PM EDT, severe thunderstorms were located along a line
  extending from 15 miles southeast of Maryville to 11 miles
  northwest of Murphy, moving east at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to trees and power lines.

* Locations impacted include...
  Robbinsville, Town Of Santeetlah, Lake Santeetlah, Fontana Lake, 
  Fontana Village, Stecoah, Nantahala, and a portion of the Smoky 
  Mountains, near Newfound Gap, Twentymile Creek, and in the Fontana 
  Area. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Scattered trees and power lines will be blown down in the warned 
area. Seek shelter inside a sturdy structure, especially an interior 
room.

These storms are producing frequent and intense lightning. Turn off
electrical appliances. Do not use corded telephones. Do not take a
bath or shower.

Please report damaging winds, hail, or flooding to the National
Weather Service Greenville-Spartanburg by calling toll free, 1, 800,
2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet it using
hashtag nwsgsp. Your message should describe the event and the
specific location where it occurred.

&&

LAT...LON 3537 8401 3541 8402 3552 8388 3553 8382
      3556 8377 3558 8360 3556 8358 3556 8350
      3561 8345 3567 8334 3566 8332 3565 8331
      3529 8364 3528 8368 3525 8370 3525 8385
      3522 8396 3523 8400 3531 8404 3535 8404
TIME...MOT...LOC 2329Z 270DEG 25KT 3559 8379 3523 8413 

HAIL...<.75IN
WIND...60MPH
 
$$

8

1 follow-up statement

214 
WWUS52 KGSP 220009
SVSGSP

Severe Weather Statement
National Weather Service Greenville-Spartanburg SC
809 PM EDT Mon Jun 21 2021

NCC075-173-220018-
/O.EXP.KGSP.SV.W.0057.000000T0000Z-210622T0015Z/
Swain NC-Graham NC-
809 PM EDT Mon Jun 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SWAIN AND GRAHAM
COUNTIES WILL EXPIRE AT 815 PM EDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However heavy rain
is still possible with these thunderstorms.

If you observed large hail or wind damage, please report it to the
National Weather Service Greenville-Spartanburg by calling toll free,
1, 800, 2 6 7, 8 1 0 1, or by posting on our Facebook page, or Tweet
it using hashtag nwsgsp. Your message should describe the event and
the specific location where it occurred.

LAT...LON 3537 8401 3541 8402 3552 8388 3553 8382
      3556 8377 3558 8360 3556 8358 3556 8350
      3561 8345 3567 8334 3566 8332 3565 8331
      3529 8364 3528 8368 3525 8370 3525 8385
      3522 8396 3523 8400 3531 8404 3535 8404
TIME...MOT...LOC 0008Z 270DEG 25KT 3559 8350 3523 8384 

$$

8

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 21, 7:00 PM EDT	Special Weather Statement	GSP	Caldwell	45 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.