Alert archive / South Carolina / Tornado Watches in 2005

Tornado Watch 831

October 7, 20054 counties in Georgia; 11 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Oct 7, 2005, 12:30 PM EDT for 4 counties in Georgia; 11 counties in South Carolina. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Oct 7, 2005, 12:30 PM EDT (16:30 UTC)
Expired: Oct 7, 2005, 7:00 PM EDT
In force: 7 hr
Issued by: the Storm Prediction Center

Counties Bryan County, GA, Bulloch County, GA, Chatham County, GA, Effingham County, GA, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dorchester County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 66 km from the middle of the area, began a volume at 16:32 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.

Discussions around it

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

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 4.5 hours before the alert went out and 39 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: 1161 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 539 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 91 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 2.7

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 071627
SEL1  
SPC WW 071627
GAZ000-SCZ000-CWZ000-072300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 831
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM EDT FRI OCT 7 2005

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

       SOUTHEASTERN GEORGIA
       EASTERN SOUTH CAROLINA
       COASTAL WATERS

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 1230 PM UNTIL 700
PM EDT.

TORNADOES...THUNDERSTORM WIND GUSTS TO 70 MPH...AND DANGEROUS
LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 35 STATUTE MILES
EITHER SIDE OF A LINE FROM 20 MILES WEST SOUTHWEST OF SAVANNAH
GEORGIA TO 20 MILES NORTH NORTHEAST OF MYRTLE BEACH SOUTH
CAROLINA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

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.

DISCUSSION...LOW LEVEL CYCLONIC CIRCULATION MOVING NNEWD FROM SERN
GA INTO ERN SC WILL BE PRIMARY FEATURE TO FOCUS FOR SUPERCELL
DEVELOPMENT. WITH 20-30 KT OF SFC-1KM SHEAR...VERY LOW LCLS
TORNADOES WILL BECOME INCREASING THREAT WITH ANY SUPERCELL ERN SC
DURING THE AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH EXTREME
TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI
WITH MAXIMUM TOPS TO 450. MEAN STORM MOTION VECTOR 19020.


...HALES

322,0815 342,0790 333,0782 313,0810

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 7, 12:09 PM EDT	Mesoscale Discussion	SPC	Bryan, Chatham, Effingham	2 hr
Oct 7, 2:51 PM EDT	Mesoscale Discussion	SPC	Bryan, Bulloch, Candler, Chatham, Effingham, Evans and 7 more	84 min
Oct 7, 5:56 PM EDT	Mesoscale Discussion	SPC	Bryan, Bulloch, Chatham, Effingham	64 min

Nearby

Tornado Watches in South Carolina, 2005 Tornado Watches in Georgia, 2005 Every tornado watch in 2005

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.