Alert archive / North Carolina / Tornado Warnings in 2011

Tornado Warning 36, NWS Raleigh, NC

April 27, 2011Forsyth County, North Carolina

NWS Raleigh, NC issued this tornado warning at Apr 27, 2011, 6:17 PM EDT for Forsyth County, North Carolina. It was in force for 43 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
Apr 27, 2011, 6:17 PM EDT (22:17 UTC)
Expired
Apr 27, 2011, 7:00 PM EDT
In force
43 min
Issued by
NWS Raleigh, NC
Area
Storm-based polygon

County Forsyth County, NC

The radar

The Roanoke radar (KFCX), 98 km from the middle of the area, began a volume at 22:18 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.

IssuedProductOfficeLasted
Apr 27, 1:23 PM EDTTornado WatchSPC5 hr
Apr 27, 6:15 PM EDTTornado WatchSPC6 hr

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 10.3 hours before the alert went out and 37 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 2011-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 446 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 2011-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 106 square meters per square second.193958Sfc1 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
446 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
564 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
106 m²/s²
0-3 km storm-relative helicity
130 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

404 
WFUS52 KRAH 272217
TORRAH
NCC067-272300-
/O.NEW.KRAH.TO.W.0036.110427T2217Z-110427T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
ISSUED BY NATIONAL WEATHER SERVICE BLACKSBURG VA
617 PM EDT WED APR 27 2011

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

* TORNADO WARNING FOR...
  FORSYTH COUNTY IN CENTRAL NORTH CAROLINA

* UNTIL 700 PM EDT.

* AT 613 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR CLEMMONS...
  OR 11 MILES NORTHEAST OF MOCKSVILLE...MOVING NORTHEAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  CLEMMONS...
  WINSTON-SALEM...

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

PLEASE RELAY SEVERE WEATHER REPORTS TO THE NATIONAL WEATHER SERVICE 
BY CALLING TOLL FREE...1...8 6 6...2 1 5...4 3 2 4.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM EDT THURSDAY MORNING
FOR CENTRAL NORTH CAROLINA.

LAT...LON 3626 8029 3626 8019 3622 8005 3606 8027
      3600 8042 3604 8047 3604 8050
TIME...MOT...LOC 2217Z 220DEG 26KT 3604 8042

$$

WP
3 follow-up statements
685 
WWUS52 KRAH 272230
SVSRAH

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
ISSUED BY NATIONAL WEATHER SERVICE BLACKSBURG VA
630 PM EDT WED APR 27 2011

NCC067-272300-
/O.CON.KRAH.TO.W.0036.000000T0000Z-110427T2300Z/
FORSYTH NC-
630 PM EDT WED APR 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM EDT FOR FORSYTH
COUNTY...

AT 626 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR LEWISVILLE...OR
NEAR WINSTON-SALEM...MOVING NORTHEAST AT 35 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
PFAFFTOWN...STANLEYVILLE...RURAL HALL AND WALKERTOWN.

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING
QUARTER SIZE HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM EDT THURSDAY MORNING
FOR CENTRAL NORTH CAROLINA.

LAT...LON 3626 8029 3626 8019 3622 8005 3606 8027
      3600 8042 3604 8047 3604 8050
TIME...MOT...LOC 2230Z 224DEG 31KT 3613 8032

$$

WP
014 
WWUS52 KRAH 272251
SVSRAH

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
ISSUED BY NATIONAL WEATHER SERVICE BLACKSBURG VA
651 PM EDT WED APR 27 2011

NCC067-272300-
/O.CON.KRAH.TO.W.0036.000000T0000Z-110427T2300Z/
FORSYTH NC-
651 PM EDT WED APR 27 2011

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 700 PM EDT FOR NORTHERN
FORSYTH COUNTY...

AT 648 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A TORNADO.  THIS TORNADO WAS LOCATED NEAR PFAFFTOWN...OR
NEAR WINSTON-SALEM...MOVING NORTHEAST AT 30 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
STANLEYVILLE...RURAL HALL AND WALKERTOWN.

IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING  
DESTRUCTIVE STRAIGHT LINE WINDS.

TO REPORT SEVERE WEATHER...PLEASE CONTACT THE NATIONAL WEATHER
SERVICE IN BLACKSBURG AT...1...8 6 6...2 1 5...4 3 2 4.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM EDT THURSDAY MORNING
FOR CENTRAL NORTH CAROLINA.

LAT...LON 3609 8028 3611 8037 3612 8040 3614 8040
      3626 8029 3626 8019 3622 8005
TIME...MOT...LOC 2251Z 230DEG 27KT 3614 8031

$$

WP
541 
WWUS52 KRAH 272257
SVSRAH

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
ISSUED BY NATIONAL WEATHER SERVICE BLACKSBURG VA
657 PM EDT WED APR 27 2011

NCC067-272307-
/O.EXP.KRAH.TO.W.0036.000000T0000Z-110427T2300Z/
FORSYTH NC-
657 PM EDT WED APR 27 2011

...THE TORNADO WARNING FOR NORTHERN FORSYTH COUNTY EXPIRES AT 700 PM
EDT...

THE THUNDERSTORM IS EXITING THE COUNTY AND THE WARNING WILL BE 
ALLOWED TO EXPIRE.

TO REPORT SEVERE WEATHER...PLEASE CONTACT THE NATIONAL WEATHER
SERVICE IN BLACKSBURG AT...1...8 6 6...2 1 5...4 3 2 4.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM EDT THURSDAY MORNING
FOR CENTRAL NORTH CAROLINA.

LAT...LON 3609 8028 3611 8037 3612 8040 3614 8040
      3626 8029 3626 8019 3622 8005
TIME...MOT...LOC 2257Z 230DEG 27KT 3617 8027

$$

WP

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 27, 1:29 PM EDTSpecial Weather StatementRAHDurham, Franklin, Granville, Vance, Wake61 min
Apr 27, 1:36 PM EDTSevere Thunderstorm WarningRAHDurham, Granville, Person, Vance, Warren54 min
Apr 27, 1:41 PM EDTSevere Thunderstorm WarningRAHDurham, Franklin, Granville, Vance, Wake, Warren64 min
Apr 27, 1:48 PM EDTSevere Thunderstorm WarningRAHDavidson, Forsyth, Guilford57 min
Apr 27, 2:01 PM EDTSevere Thunderstorm WarningRAHEdgecombe, Halifax, Nash59 min
Apr 27, 2:12 PM EDTSevere Thunderstorm WarningRAHEdgecombe, Halifax, Nash, Wayne, Wilson42 min
Apr 27, 5:43 PM EDTSevere Thunderstorm WarningRAHDavidson, Forsyth, Guilford, Randolph62 min
Apr 27, 6:06 PM EDTSevere Thunderstorm WarningRAHDurham, Granville, Orange, Person32 min
Apr 27, 6:19 PM EDTTornado WarningRAHDavidson, Forsyth, Guilford41 min
Apr 27, 7:06 PM EDTSpecial Weather StatementRAHGuilford39 min

Nearby

Tornado Warnings in North Carolina, 2011Every tornado warning in 2011Tornadoes 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.