Alert archive / North Carolina / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 386, NWS Blacksburg, VA

July 4, 2011Grayson County, Virginia; Ashe County, Watauga County, North Carolina

NWS Blacksburg, VA issued this severe thunderstorm warning at Jul 4, 2011, 1:42 PM EDT for Grayson County, Virginia; Ashe County, Watauga County, North Carolina. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 4, 2011, 1:42 PM EDT (17:42 UTC)
Expired: Jul 4, 2011, 2:45 PM EDT
In force: 63 min
Issued by: NWS Blacksburg, VA
Area: Storm-based polygon

Counties Ashe County, NC, Watauga County, NC, Grayson County, VA

The radar

The Roanoke radar (KFCX), 125 km from the middle of the area, began a volume at 17:45 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 4, 12:50 PM EDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 5.7 hours before the alert went out and 147 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: 880 J/kg
Mixed-layer CIN: -120 J/kg
Mixed-layer LCL: 1130 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Blacksburg, VA wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 4, 12:56 PM EDT, 46 minutes earlier.

Area forecast discussion, Jul 4, 12:56 PM EDT, 46 minutes before

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Hazardous weather outlook, Jul 4, 1:00 PM EDT, 42 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE BLACKSBURG VA
100 PM EDT MON JUL 4 2011

NCZ001>006-018>020-VAZ007-009>018-022>024-032>035-043>047-058-059-
WVZ042-051700-
ASHE-ALLEGHANY NC-SURRY-STOKES-ROCKINGHAM-CASWELL-WATAUGA-WILKES-
YADKIN-TAZEWELL-SMYTH-BLAND-GILES-WYTHE-PULASKI-MONTGOMERY-GRAYSON-
CARROLL-FLOYD-CRAIG-ROANOKE-BOTETOURT-ROCKBRIDGE-PATRICK-FRANKLIN-
BEDFORD-AMHERST-HENRY-PITTSYLVANIA-CAMPBELL-APPOMATTOX-BUCKINGHAM-
HALIFAX-CHARLOTTE-MERCER-
100 PM EDT MON JUL 4 2011

...SEVERE THUNDERSTORM WATCH 594 IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL NORTH
CAROLINA...NORTHWEST NORTH CAROLINA...CENTRAL VIRGINIA...SOUTH
CENTRAL VIRGINIA...SOUTHWEST VIRGINIA...WEST CENTRAL VIRGINIA AND
SOUTHEAST WEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE
INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS.

   SEVERE THUNDERSTORM WATCH.

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXITS THIS AFTERNOON AND
EARLY EVENING. CLUSTERS OF SLOW MOVING THUNDERSTORMS ARE LIKELY
THIS AFTERNOON AND EARLY EVENING. DAMAGING WINDS WILL BE THE
GREATEST THREAT WITH SOME OF THESE STORMS WITH MARGINALLY LARGE
HAIL A SECONDARY THREAT. ANOTHER CONCERN IS LOCALLY HEAVY RAINFALL
AND FREQUENT CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE NOW ACTIVATED. PLEASE RELAY REPORTS OF SEVERE
WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.

VAZ019-020-WVZ043>045-051700-
ALLEGHANY VA-BATH-SUMMERS-MONROE-GREENBRIER-
100 PM EDT MON JUL 4 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL VIRGINIA AND
SOUTHEAST WEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A SLIGHT RISK OF SEVERE THUNDERSTORMS EXITS THIS AFTERNOON AND
EARLY EVENING. CLUSTERS OF SLOW MOVING THUNDERSTORMS ARE LIKELY
THIS AFTERNOON AND EARLY EVENING. DAMAGING WINDS WILL BE THE
GREATEST THREAT WITH AN ISOLATED NUMBER OF THESE STORMS WITH
MARGINALLY LARGE HAIL A SECONDARY THREAT. ANOTHER CONCERN IS
LOCALLY HEAVY RAINFALL AND FREQUENT CLOUD TO GROUND LIGHTNING.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED.

DS

In the hours before

Local storm report, Jul 4, 8:45 AM EDT, 4 hours 57 minutes before

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Local storm report, Jul 4, 9:39 AM EDT, 4 hours 3 minutes before

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Local storm report, Jul 4, 10:20 AM EDT, 3 hours 22 minutes before

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Local storm report, Jul 4, 10:42 AM EDT, 3 hours before

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Special weather statement, Jul 4, 12:47 PM EDT, 55 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BLACKSBURG VA
1247 PM EDT MON JUL 4 2011

VAZ013-014-017-041745-
FLOYD VA-MONTGOMERY VA-PULASKI VA-
1247 PM EDT MON JUL 4 2011

...A STRONG THUNDERSTORM WILL AFFECT FLOYD...MONTGOMERY AND PULASKI
COUNTIES...

AT 1246 PM EDT...A STRONG THUNDERSTORM WAS LOCATED OVER DUBLIN...
MOVING EAST AT 20 MPH.

WIND GUSTS TO 30 MPH ARE POSSIBLE WITH THIS STORM. IF ON OR NEAR
CLAYTOR LAKE...GET OUT OF THE WATER AND MOVE INDOORS OR INSIDE A
VEHICLE. SUDDEN WIND GUSTS MAY BE STRONG ENOUGH TO CAPSIZE YOUR
VESSEL.

THIS STORM WILL BE NEAR CLAYTOR LAKE STATE PARK AROUND 1255 PM...
CLAYTOR DAM AROUND 100 PM...RADFORD...FAIRLAWN...AND GRAYSONTOWN
AROUND 105 PM...WALTON...AND COPPER VALLEY AROUND 110
PM...CHILDRESS...AND PRICES FORK AROUND 115 PM.

LAT...LON 3704 8078 3719 8076 3722 8067 3723 8020
      3688 8022 3686 8027

AMS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 3, 8:54 PM EDT	Special Weather Statement	RNK	Botetourt	66 min
Jul 3, 9:42 PM EDT	Special Weather Statement	RNK	Smyth	63 min
Jul 4, 12:47 PM EDT	Special Weather Statement	RNK	Floyd, Montgomery, Pulaski, City of Radford	58 min
Jul 4, 1:34 PM EDT	Severe Thunderstorm Warning	RNK	Grayson	56 min
Jul 4, 2:00 PM EDT	Special Weather Statement	RNK	Franklin, Pittsylvania	60 min
Jul 4, 2:07 PM EDT	Severe Thunderstorm Warning	RNK	Tazewell	53 min
Jul 4, 2:13 PM EDT	Severe Thunderstorm Warning	RNK	Smyth, Tazewell	62 min
Jul 4, 2:18 PM EDT	Special Weather Statement	RNK	Montgomery	27 min
Jul 4, 2:27 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Craig	63 min
Jul 4, 2:48 PM EDT	Flash Flood Watch	RNK	Alleghany, Amherst, Appomattox, Bath, Bedford, Bland and 31 more	4 hr
Jul 4, 2:48 PM EDT	Special Weather Statement	RNK	Giles	57 min
Jul 4, 2:52 PM EDT	Flash Flood Warning	RNK	Franklin, Henry	5 hr
Jul 4, 3:00 PM EDT	Severe Thunderstorm Warning	RNK	Botetourt, Craig, Roanoke, City of Roanoke, City of Salem	48 min
Jul 4, 3:12 PM EDT	Special Weather Statement	RNK	Bland, Pulaski, Smyth, Wythe	63 min
Jul 4, 3:21 PM EDT	Severe Thunderstorm Warning	RNK	Bedford, Franklin, Roanoke	54 min
Jul 4, 3:25 PM EDT	Severe Thunderstorm Warning	RNK	Halifax, Pittsylvania	65 min
Jul 4, 3:55 PM EDT	Special Weather Statement	RNK	Franklin, Montgomery, City of Radford	65 min
Jul 4, 4:05 PM EDT	Severe Thunderstorm Warning	RNK	Charlotte	55 min
Jul 4, 4:06 PM EDT	Severe Thunderstorm Warning	RNK	Amherst, Bedford, Botetourt, Rockbridge, City of Buena Vista, City of Lexington	54 min
Jul 4, 4:25 PM EDT	Severe Thunderstorm Warning	RNK	Charlotte, Halifax	65 min
Jul 4, 4:46 PM EDT	Severe Thunderstorm Warning	RNK	Amherst, Appomattox, Buckingham	59 min
Jul 4, 4:57 PM EDT	Severe Thunderstorm Warning	RNK	Pittsylvania, City of Danville	52 min
Jul 4, 5:04 PM EDT	Severe Thunderstorm Warning	RNK	Charlotte	26 min
Jul 4, 5:17 PM EDT	Severe Thunderstorm Warning	RNK	Patrick	58 min
Jul 4, 5:31 PM EDT	Severe Thunderstorm Warning	RNK	Pittsylvania	59 min
Jul 4, 5:47 PM EDT	Severe Thunderstorm Warning	RNK	Buckingham	28 min
Jul 4, 6:11 PM EDT	Areal Flood Advisory	RNK	Pittsylvania, City of Danville	2 hr
Jul 4, 2:56 PM EDT	Severe Thunderstorm Warning	RNK	Wilkes	64 min
Jul 4, 3:29 PM EDT	Special Weather Statement	RNK	Surry	61 min
Jul 4, 3:33 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Surry, Wilkes	57 min
Jul 4, 4:10 PM EDT	Special Weather Statement	RNK	Wilkes	35 min
Jul 4, 4:16 PM EDT	Severe Thunderstorm Warning	RNK	Surry, Yadkin	29 min
Jul 4, 4:33 PM EDT	Severe Thunderstorm Warning	RNK	Alleghany, Stokes, Surry, Wilkes, Yadkin	57 min
Jul 4, 4:49 PM EDT	Severe Thunderstorm Warning	RNK	Stokes, Surry, Yadkin	26 min
Jul 4, 5:52 PM EDT	Special Weather Statement	RNK	Caswell	23 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2011 Severe Thunderstorm Warnings in Virginia, 2011 Every severe thunderstorm warning in 2011

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.