Alert archive / North Carolina / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 331, NWS Raleigh, NC

August 29, 2011Alamance County, Guilford County, North Carolina

NWS Raleigh, NC issued this severe thunderstorm warning at Aug 29, 2011, 4:55 PM EDT for Alamance County, Guilford County, North Carolina. It was in force for 50 min. 5 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 29, 2011, 4:55 PM EDT (20:55 UTC)
Expired
Aug 29, 2011, 5:45 PM EDT
In force
50 min
Issued by
NWS Raleigh, NC
Area
Storm-based polygon

Counties Alamance County, NC, Guilford County, NC

The radar

The Raleigh/Durham radar (KRAX), 94 km from the middle of the area, began a volume at 20:55 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 29, 5:10 PM EDTHAIL 11 Ssw Graham, NCQUARTER SIZE HAIL AT FORENCE AND TODD STREETS
Aug 29, 5:15 PM EDTTSTM WND DMG2 Sse Burlington, NCTREE DOWN ON HOUSE
Aug 29, 5:15 PM EDTTSTM WND DMG2 Sw Graham, NCMULTIPLE TREES DOWN
Aug 29, 5:15 PM EDTTSTM WND DMG3 Ene Swepsonville, NCTWO TREES BLOWN DOWN THAT BLOCKED TURNER ROAD
Aug 29, 5:26 PM EDTTSTM WND DMG2 Sw Graham, NCMULTIPLE TREES DOWN

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, 8.9 hours before the alert went out and 45 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 2011-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2011-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1514 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

560 
WUUS52 KRAH 292055
SVRRAH
NCC001-081-292145-
/O.NEW.KRAH.SV.W.0331.110829T2055Z-110829T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE RALEIGH NC
455 PM EDT MON AUG 29 2011

THE NATIONAL WEATHER SERVICE IN RALEIGH HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN ALAMANCE COUNTY IN CENTRAL NORTH CAROLINA
  EASTERN GUILFORD COUNTY IN CENTRAL NORTH CAROLINA

* UNTIL 545 PM EDT

* AT 450 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER MCLEANSVILLE...OR 9 MILES WEST OF
  BURLINGTON...MOVING EAST AT 25 MPH. QUARTER SIZED HAIL AND WINDS IN
  EXCESS OF 58 MPH ARE LIKELY WITH THIS STORM.

* LOCATIONS IMPACTED INCLUDE...
  GIBSONVILLE...
  ELON COLLEGE...ALAMANCE...
  BURLINGTON...GLEN RAVEN...
  GRAHAM...SWEPSONVILLE...
  HAW RIVER...
  MEBANE...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

LARGE HAIL WILL DAMAGE VEHICLES...WINDOWS AND SOME ROOFS. SEVERE
WINDS WILL BLOW DOWN TREES...POWER LINES...AND CAN DAMAGE MOBILE
HOMES AND OTHER BUILDINGS. SEEK SHELTER IN A STURDY STRUCTURE UNTIL
THE STORM HAS PASSED. STAY AWAY FROM WINDOWS.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A VEHICLE OR A NEARBY
BUILDING. AS A LAST RESORT...LIE DOWN IN A LOW LYING AREA AND COVER
YOUR HEAD WITH YOUR HANDS.

PLEASE REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE BY
CALLING...1...8 7 7...6 3 3...6 7 7 2 OR NOTIFY YOUR LOCAL LAW
ENFORCEMENT AGENCY.


&&

LAT...LON 3600 7926 3597 7927 3596 7968 3620 7970
      3625 7926
TIME...MOT...LOC 2054Z 265DEG 21KT 3608 7957

$$

10
2 follow-up statements
966 
WWUS52 KRAH 292110
SVSRAH

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
510 PM EDT MON AUG 29 2011

NCC081-292119-
/O.CAN.KRAH.SV.W.0331.000000T0000Z-110829T2145Z/
GUILFORD NC-
510 PM EDT MON AUG 29 2011

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN GUILFORD COUNTY IS
CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA AND 
THE WARNING IS NO LONGER IN EFFECT. 

IF YOU OBSERVED SEVERE WEATHER INCLUDING DAMAGING WINDS OR LARGE
HAIL...PLEASE CONTACT THE NATIONAL WEATHER SERVICE BY CALLING TOLL
FREE 1...8 7 7...6 3 3...6 7 7 2...OR NOTIFY YOUR NEAREST LAW
ENFORCEMENT AGENCY AND ASK THEM TO RELAY YOUR REPORT TO THE NATIONAL
WEATHER SERVICE FORECAST OFFICE IN RALEIGH.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1100 PM EDT
MONDAY EVENING FOR CENTRAL NORTH CAROLINA.

LAT...LON 3625 7926 3607 7926 3597 7927 3596 7954
      3619 7954
TIME...MOT...LOC 2109Z 280DEG 27KT 3605 7944

$$

NCC001-292145-
/O.CON.KRAH.SV.W.0331.000000T0000Z-110829T2145Z/
ALAMANCE NC-
510 PM EDT MON AUG 29 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM EDT
FOR NORTHERN ALAMANCE COUNTY...

AT 505 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM.  THIS STORM WAS LOCATED NEAR
ALAMANCE...OR NEAR BURLINGTON...MOVING EAST AT 30 MPH.

HAZARDS IN THE WARNING INCLUDE...
QUARTER SIZED HAIL.
DAMAGING WINDS IN EXCESS OF 58 MPH.

LOCATIONS IN THE PATH OF THE STORM INCLUDE... UNION RIDGE...GRAHAM...
HAW RIVER...PLEASANT GROVE...SWEPSONVILLE AND MEBANE.

LARGE HAIL WILL DAMAGE VEHICLES...WINDOWS AND SOME ROOFS. SEVERE
WINDS WILL BLOW DOWN TREES...POWER LINES...AND CAN DAMAGE MOBILE
HOMES AND OTHER BUILDINGS. SEEK SHELTER IN A STURDY STRUCTURE UNTIL
THE STORM HAS PASSED. STAY AWAY FROM WINDOWS.

WHEN IT IS SAFE TO DO SO...PLEASE CALL IN YOUR REPORTS OF PENNY OR
LARGER SIZED HAIL...AS WELL AS WIND DAMAGE...INCLUDING TREES OR LARGE
LIMBS DOWNED BY CALLING THE NATIONAL WEATHER SERVICE TOLL FREE AT...
1...8 7 7...6 3 3...6 7 7 2.

LAT...LON 3625 7926 3607 7926 3597 7927 3596 7954
      3619 7954
TIME...MOT...LOC 2109Z 280DEG 27KT 3605 7944

$$

10
918 
WWUS52 KRAH 292143
SVSRAH

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE RALEIGH NC
543 PM EDT MON AUG 29 2011

NCC001-292153-
/O.EXP.KRAH.SV.W.0331.000000T0000Z-110829T2145Z/
ALAMANCE NC-
543 PM EDT MON AUG 29 2011

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN ALAMANCE COUNTY
EXPIRES AT 545 PM EDT...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA AND 
THE WARNING WILL BE ALLOWED TO EXPIRE. 

IF YOU OBSERVED SEVERE WEATHER INCLUDING DAMAGING WINDS OR LARGE
HAIL...PLEASE CONTACT THE NATIONAL WEATHER SERVICE BY CALLING TOLL
FREE 1...8 7 7...6 3 3...6 7 7 2...OR NOTIFY YOUR NEAREST LAW
ENFORCEMENT AGENCY AND ASK THEM TO RELAY YOUR REPORT TO THE NATIONAL
WEATHER SERVICE FORECAST OFFICE IN RALEIGH.

WHILE THE IMMEDIATE SEVERE WEATHER THREAT HAS DISSIPATED...ADDITIONAL
SEVERE WEATHER IS POSSIBLE DURING THE NEXT FEW HOURS. BE PREPARED TO
MOVE QUICKLY TO AN INTERIOR ROOM OF A SAFE SHELTER IF A WARNING IS
ISSUED.

LAT...LON 3625 7926 3607 7926 3597 7927 3596 7954
      3619 7954
TIME...MOT...LOC 2143Z 280DEG 27KT 3600 7913

$$

10

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 3:52 PM EDTSpecial Weather StatementRAHAlamance, Chatham, Durham, Franklin, Granville, Orange and 3 more53 min
Aug 29, 4:13 PM EDTSevere Thunderstorm WarningRAHDurham, Franklin, Granville, Wake62 min
Aug 29, 4:35 PM EDTSpecial Weather StatementRAHRichmond55 min
Aug 29, 4:42 PM EDTSevere Thunderstorm WarningRAHDurham, Granville, Person63 min
Aug 29, 4:44 PM EDTSpecial Weather StatementRAHAlamance, Orange61 min
Aug 29, 4:48 PM EDTSevere Thunderstorm WarningRAHMontgomery, Richmond57 min
Aug 29, 5:05 PM EDTSevere Thunderstorm WarningRAHFranklin, Nash55 min
Aug 29, 5:14 PM EDTSevere Thunderstorm WarningRAHFranklin, Johnston, Wake24 min
Aug 29, 5:21 PM EDTSevere Thunderstorm WarningRAHAlamance, Orange39 min
Aug 29, 5:37 PM EDTSpecial Weather StatementRAHMontgomery, Moore53 min
Aug 29, 6:01 PM EDTSevere Thunderstorm WarningRAHEdgecombe, Halifax, Nash44 min
Aug 29, 6:06 PM EDTSevere Thunderstorm WarningRAHChatham39 min
Aug 29, 6:08 PM EDTSpecial Weather StatementRAHGranville, Vance67 min
Aug 29, 6:13 PM EDTTornado WarningRAHEdgecombe, Nash, Wilson47 min
Aug 29, 6:19 PM EDTSpecial Weather StatementRAHAnson, Montgomery, Richmond, Stanly56 min
Aug 29, 6:30 PM EDTSpecial Weather StatementRAHWake60 min
Aug 29, 6:41 PM EDTTornado WarningRAHEdgecombe34 min
Aug 29, 6:45 PM EDTSevere Thunderstorm WarningRAHChatham, Harnett, Wake45 min
Aug 29, 6:47 PM EDTSpecial Weather StatementRAHFranklin, Nash58 min
Aug 29, 6:53 PM EDTSpecial Weather StatementRAHLee, Moore52 min
Aug 29, 7:04 PM EDTSevere Thunderstorm WarningRAHFranklin, Wake41 min
Aug 29, 7:15 PM EDTAreal Flood AdvisoryRAHAnson63 min
Aug 29, 7:22 PM EDTAreal Flood AdvisoryRAHWake2 hr
Aug 29, 7:25 PM EDTSpecial Weather StatementRAHAnson, Montgomery, Richmond, Stanly50 min
Aug 29, 7:29 PM EDTSpecial Weather StatementRAHHarnett61 min
Aug 29, 7:30 PM EDTFlash Flood WarningRAHEdgecombe, Nash3 hr
Aug 29, 7:41 PM EDTAreal Flood AdvisoryRAHFranklin, Nash2 hr

Nearby

Severe Thunderstorm Warnings in North Carolina, 2011Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.