Alert archive / North Carolina / Severe Thunderstorm Watches in 2008

Severe Thunderstorm Watch 310

May 11, 200826 counties in North Carolina

The Storm Prediction Center issued this severe thunderstorm watch at May 11, 2008, 7:47 PM EDT for 26 counties in North Carolina. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
May 11, 2008, 7:47 PM EDT (23:47 UTC)
Expired
May 11, 2008, 10:59 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 26 counties

Alamance County, NC, Anson County, NC, Chatham County, NC, Cumberland County, NC, Davidson County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Guilford County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Randolph County, NC, Richmond County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC

The radar

The Raleigh/Durham radar (KRAX), 52 km from the middle of the area, began a volume at 23:46 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 11, 7:51 PM EDTSevere Thunderstorm WarningRAHDavidson, Forsyth, Guilford, Randolph39 min
May 11, 8:34 PM EDTSevere Thunderstorm WarningRAHAlamance, Chatham, Davidson, Guilford, Randolph41 min
May 11, 10:06 PM EDTSevere Thunderstorm WarningRAHHarnett, Johnston, Wayne, Wilson54 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.8 hours before the alert went out and 99 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 2008-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2008-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 square meters per square second.1939587897Sfc1 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
951 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
262 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.

000
WWUS20 KWNS 112346
SEL0  
SPC WW 112346
NCZ000-120300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 310
NWS STORM PREDICTION CENTER NORMAN OK
745 PM EDT SUN MAY 11 2008

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 

       CENTRAL NORTH CAROLINA

EFFECTIVE THIS SUNDAY EVENING FROM 745 PM UNTIL 1100 PM EDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTHEAST OF
RALEIGH NORTH CAROLINA TO 40 MILES SOUTHWEST OF FAYETTEVILLE
NORTH CAROLINA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
TORNADO WATCH NUMBER 307. WATCH NUMBER 307 WILL NOT BE IN EFFECT
AFTER 745 PM EDT. CONTINUE...WW 308...WW 309...

DISCUSSION...COMPLEX SETUP ACROSS NC THIS EVENING WITH STRONG UPPER
SYSTEM AND COLD TEMPERATURES ALOFT MAINTAINING THUNDERSTORMS
SPREADING EWD ACROSS THE STATE...DESPITE EARLIER THUNDERSTORM
ACTIVITY MOVING ACROSS ERN NC.  IN WAKE OF SURFACE LOW AND LEADING
TROUGH OVER ERN NC EARLY THIS EVENING...WLY WINDS AND DRYING SURFACE
CONDITIONS APPEAR TO HAVE LIMITED TORNADO POTENTIAL OVER CENTRAL NC.
 HOWEVER...VERY STEEP LAPSE RATES AND 35-45 KT EFFECTIVE SHEAR
SHOULD STILL SUPPORT A FEW SUPERCELLS/ORGANIZED CLUSTERS WITH
PRIMARY THREATS OF LARGE HAIL AND ISOLATED DAMAGING WINDS FOR A FEW
MORE HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM
MOTION VECTOR 27035.


...EVANS

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 9:34 AM EDTMesoscale DiscussionSPCAshe, Avery, Buncombe, Graham, Haywood, Madison and 4 more26 min
May 11, 9:52 AM EDTTornado WatchSPCAvery, Buncombe, Cherokee, Clay, Graham, Haywood and 8 more6 hr
May 11, 1:39 PM EDTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Brunswick and 49 more2 hr
May 11, 2:07 PM EDTTornado WatchSPCAlamance, Alexander, Anson, Bladen, Cabarrus, Caswell and 43 more6 hr
May 11, 2:33 PM EDTMesoscale DiscussionSPCAshe, Watauga57 min
May 11, 4:18 PM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Chatham, Chowan, Cumberland and 26 more87 min
May 11, 4:43 PM EDTTornado WatchSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 23 more6 hr
May 11, 7:30 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Brunswick, Camden, Carteret, Chowan and 20 more90 min
May 10, 8:14 PM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 6 more2 hr
May 10, 9:54 PM EDTMesoscale DiscussionSPCAllendale, Bamberg, Barnwell, Beaufort, Colleton, Hampton and 1 more96 min
May 10, 10:06 PM EDTTornado WatchSPCAllendale, Beaufort, Colleton, Hampton, Jasper7 hr
May 11, 2:06 AM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Edgefield, Hampton and 2 more84 min
May 11, 2:37 AM EDTTornado WatchSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 12 more7 hr
May 11, 4:40 AM EDTMesoscale DiscussionSPCAbbeville, Aiken, Allendale, Bamberg, Barnwell, Beaufort and 14 more95 min
May 11, 7:24 AM EDTMesoscale DiscussionSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 13 more96 min
May 11, 8:51 AM EDTMesoscale DiscussionSPCAllendale, Bamberg, Barnwell, Beaufort, Berkeley, Calhoun and 5 more84 min
May 11, 2:42 PM EDTTornado WatchSPCBeaufort, Charleston, Colleton, Jasper5 hr
May 11, 7:06 PM EDTMesoscale DiscussionSPCBeaufort, Charleston, Colleton, Jasper84 min

Nearby

Severe Thunderstorm Watches in North Carolina, 2008Every severe thunderstorm watch in 2008

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.