Alert archive / Georgia / Tornado Watches in 2008

Tornado Watch 67

February 18, 200817 counties in Florida; 26 counties in Georgia

The Storm Prediction Center issued this tornado watch at Feb 18, 2008, 2:57 AM EST for 17 counties in Florida; 26 counties in Georgia. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Feb 18, 2008, 2:57 AM EST (07:57 UTC)
Expired: Feb 18, 2008, 10:00 AM EST
In force: 7 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

All 43 counties

Baker County, FL, Columbia County, FL, Dixie County, FL, Franklin County, FL, Gadsden County, FL, Gilchrist County, FL, Gulf County, FL, Hamilton County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Wakulla County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Ben Hill County, GA, Berrien County, GA, Brantley County, GA, Brooks County, GA, Camden County, GA, Charlton County, GA, Clinch County, GA, Coffee County, GA, Colquitt County, GA, Cook County, GA, Echols County, GA, Glynn County, GA, Grady County, GA, Irwin County, GA, Jeff Davis County, GA, Lanier County, GA, Lowndes County, GA, Pierce County, GA, Thomas County, GA, Tift County, GA, Ware County, GA, Wayne County, GA, Worth County, GA

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: 20%
Ten or more severe wind reports: 20%
One or more gusts of 65 knots or more: 5%
Ten or more severe hail reports: 10%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 60%

Discussions around it

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

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 8.0 hours before the alert went out and 92 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: 593 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 478 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 274 m²/s²
0-3 km storm-relative helicity: 290 m²/s²
Significant tornado parameter: 0.9
Supercell composite: 6.1

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 180800
SEL7  
SPC WW 180800
FLZ000-GAZ000-CWZ000-181500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 67
NWS STORM PREDICTION CENTER NORMAN OK
300 AM EST MON FEB 18 2008

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

       EASTERN FLORIDA PANHANDLE AND NORTH FLORIDA
       SOUTH CENTRAL AND SOUTHEAST GEORGIA
       COASTAL WATERS

EFFECTIVE THIS MONDAY MORNING FROM 300 AM UNTIL 1000 AM EST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF WAYCROSS
GEORGIA TO 35 MILES EAST SOUTHEAST OF APALACHICOLA FLORIDA.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU7).

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...CONTINUE...WW 66...

DISCUSSION...SRN END OF LONG-LIVED BROKEN SQLN IN GA/NW FL EXPECTED
TO CONTINUE TO CONTAIN OCCASIONAL EMBEDDED SUPERCELLS/SUSTAINED
STORMS THAT...GIVEN STRENGTH OF LOW TO MID-LEVEL SHEAR...WILL POSE
ADDITIONAL RISK FOR ISOLATED DAMAGING WIND GUSTS/POSSIBLE TORNADOES.
 WHILE LOW-LEVEL MOISTURE INFLOW SHOULD BE MORE LIMITED WITH ERN/NRN
EXTENT IN WATCH...SOME DESTABILIZATION MAY BE PROVIDED BY
ASCENT/COOLING ALOFT ASSOCIATED WITH PROGRESSIVE LARGE SCALE UPR
TROUGH.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 24035.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 17, 8:34 PM EST	Mesoscale Discussion	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 9 more	56 min
Feb 17, 11:35 PM EST	Mesoscale Discussion	SPC	Bay, Calhoun, Franklin, Gadsden, Gulf, Hamilton and 9 more	85 min
Feb 18, 2:39 AM EST	Mesoscale Discussion	SPC	Columbia, Dixie, Franklin, Gadsden, Gilchrist, Hamilton and 8 more	36 min
Feb 18, 5:11 AM EST	Mesoscale Discussion	SPC	Baker, Columbia, Dixie, Franklin, Gadsden, Gilchrist and 12 more	64 min
Feb 18, 7:43 AM EST	Mesoscale Discussion	SPC	Baker, Bradford, Columbia, Dixie, Gilchrist, Hamilton and 7 more	62 min
Feb 18, 8:46 AM EST	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Columbia, Gilchrist, Levy and 2 more	29 min
Feb 18, 10:36 AM EST	Mesoscale Discussion	SPC	Flagler, Hernando, Lake, Marion, Orange, Pasco and 5 more	84 min

Nearby

Tornado Watches in Georgia, 2008 Tornado Watches in Florida, 2008 Every 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.