Alert archive / South Carolina / Tornado Watches in 2008

Tornado Watch 869

August 27, 200812 counties in North Carolina; 18 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Aug 27, 2008, 1:56 AM EDT for 12 counties in North Carolina; 18 counties in South Carolina. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Aug 27, 2008, 1:56 AM EDT (05:56 UTC)
Expired
Aug 27, 2008, 10:00 AM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
50 kt
All 30 counties

Anson County, NC, Cabarrus County, NC, Cleveland County, NC, Davidson County, NC, Gaston County, NC, Lincoln County, NC, Mecklenburg County, NC, Montgomery County, NC, Randolph County, NC, Richmond County, NC, Stanly County, NC, Union County, NC, Aiken County, SC, Calhoun County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Edgefield County, SC, Fairfield County, SC, Greenwood County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lexington County, SC, McCormick County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, Union County, SC, York County, SC

The radar

The Greer radar (KGSP), 87 km from the middle of the area, began a volume at 05:59 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
30%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
5%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
20%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Aug 27, 4:13 AM EDTFlash Flood WarningGSPCabarrus, Mecklenburg3 hr
Aug 27, 4:27 AM EDTFlash Flood WarningRAHDavidson4 hr
Aug 27, 6:49 AM EDTFlash Flood WarningRAHRandolph116 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 00:00Z, 5.9 hours before the alert went out and 193 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 00:00Z on 2008-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 148 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 00:00Z on 2008-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 193 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
148 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
474 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
193 m²/s²
0-3 km storm-relative helicity
247 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 270556
SEL9  
SPC WW 270556
NCZ000-SCZ000-271400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 869
NWS STORM PREDICTION CENTER NORMAN OK
155 AM EDT WED AUG 27 2008

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

       SOUTHERN NORTH CAROLINA
       CENTRAL SOUTH CAROLINA

EFFECTIVE THIS WEDNESDAY MORNING FROM 155 AM UNTIL 1000 AM EDT.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH NORTHEAST OF
CHARLOTTE NORTH CAROLINA TO 35 MILES SOUTHWEST OF COLUMBIA SOUTH
CAROLINA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 868. WATCH NUMBER 868 WILL NOT BE IN EFFECT AFTER
155 AM EDT. 

DISCUSSION...ISOLD SUSTAINED STORMS/POSSIBLE SUPERCELLS SHOULD
PERSIST ALONG 35-40 KT SSWLY LLJ OVER THE SC PIEDMONT.  GIVEN DEGREE
OF LOW LVL SHEAR /WITH A SIZABLE DIRECTIONAL COMPONENT/ AND RICH
MOISTURE AVAILABILITY...A LOW PROBABILITY THREAT WILL EXIST FOR
TORNADOES WITH STRONGER CELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 21035.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 26, 10:10 PM EDTMesoscale DiscussionSPCAnson, Gaston, Union95 min
Aug 27, 4:52 AM EDTMesoscale DiscussionSPCCabarrus, Davidson, Davie, Forsyth, Iredell, Mecklenburg and 3 more83 min
Aug 27, 8:44 AM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Carteret, Chowan, Columbus and 25 more91 min
Aug 27, 9:16 AM EDTTornado WatchSPCAlamance, Anson, Beaufort, Bertie, Bladen, Camden and 52 more8 hr
Aug 27, 12:24 PM EDTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Camden and 53 more66 min
Aug 27, 2:34 PM EDTMesoscale DiscussionSPCAlamance, Anson, Beaufort, Bertie, Bladen, Camden and 52 more56 min
Aug 27, 4:26 PM EDTMesoscale DiscussionSPCAlamance, Anson, Bertie, Bladen, Chatham, Cumberland and 35 more34 min

Nearby

Tornado Watches in South Carolina, 2008Tornado Watches in North Carolina, 2008Every tornado 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.