Alert archive / Florida / Tornado Watches in 2008

Tornado Watch 938

November 30, 200812 counties in Florida; 11 counties in Georgia

The Storm Prediction Center issued this tornado watch at Nov 30, 2008, 4:59 AM EST for 12 counties in Florida; 11 counties in Georgia. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Nov 30, 2008, 4:59 AM EST (09:59 UTC)
Expired
Nov 30, 2008, 12:00 PM EST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 23 counties

Columbia County, FL, Dixie County, FL, Franklin County, FL, Gilchrist County, FL, Hamilton County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Wakulla County, FL, Atkinson County, GA, Berrien County, GA, Brooks County, GA, Clinch County, GA, Colquitt County, GA, Cook County, GA, Echols County, GA, Grady County, GA, Lanier County, GA, Lowndes County, GA, Thomas County, GA

The radar

The Tallahassee radar (KTLH), 45 km from the middle of the area, began a volume at 09:59 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
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
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
Nov 30, 6:01 AM ESTTornado WarningTAETaylor29 min
Nov 30, 7:15 AM ESTSevere Thunderstorm WarningTAETaylor30 min
Nov 30, 9:14 AM ESTSevere Thunderstorm WarningTAEDixie46 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

Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 10.0 hours before the alert went out and 42 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, Tallahassee Rgnl, FL at 00:00Z on 2008-11-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 306 joules per kilogram.LCLEL10008507005003002001001 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, Tallahassee Rgnl, FL at 00:00Z on 2008-11-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
306 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
486 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.2
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 301002
SEL8  
SPC WW 301002
FLZ000-GAZ000-CWZ000-301700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 938
NWS STORM PREDICTION CENTER NORMAN OK
500 AM EST SUN NOV 30 2008

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

       NORTHERN FLORIDA
       SOUTHERN GEORGIA
       COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING FROM 500 AM UNTIL NOON 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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH OF VALDOSTA
GEORGIA TO 50 MILES EAST SOUTHEAST OF APALACHICOLA FLORIDA.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU8).

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...TSTMS ARE EXPECTED TO INTENSIFY THIS MORNING WITHIN
PRE-FRONTAL CONVECTIVE BAND FROM THE NERN GULF OF MEXICO INTO SRN
GA.  WHILE ENVIRONMENT IS FORECAST TO REMAIN ONLY MARGINALLY
UNSTABLE WITH MLCAPE AOB 500 J/KG...INCREASING LARGE-SCALE ASCENT
AHEAD OF AMPLIFYING UPPER TROUGH AND ENHANCED LOW-LEVEL CONVERGENCE
COINCIDENT WITH SUB-SYNOPTIC SCALE LOW DEVELOPING NEWD SHOULD FOCUS
CLUSTERS OF ORGANIZED TSTMS.  GIVEN THE STRONG AMBIENT SHEAR /I.E.
0-1 KM SHEAR OF AROUND 40 KT AND 0-6 KM SHEAR OF 60-65 KT/ AND MOIST
BOUNDARY LAYER CONDITIONS...POTENTIAL WILL EXIST FOR EMBEDDED
SUPERCELL AND BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND
PERHAPS A TORNADO OR TWO.

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 400.
MEAN STORM MOTION VECTOR 22045.


...MEAD/THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 30, 3:46 AM ESTMesoscale DiscussionSPCColumbia, Franklin, Hamilton, Jefferson, Lafayette, Leon and 4 more89 min
Nov 30, 7:54 AM ESTMesoscale DiscussionSPCAlachua, Baker, Bradford, Columbia, Dixie, Gilchrist and 4 more96 min
Nov 30, 9:51 AM ESTTornado WatchSPCAlachua, Baker, Bradford, Citrus, Clay, Duval and 18 more7 hr
Nov 30, 12:24 PM ESTMesoscale DiscussionSPCFlagler, Hillsborough, Lake, Marion, Orange, Osceola and 6 more96 min
Nov 30, 1:05 PM ESTTornado WatchSPCBrevard, Broward, Charlotte, Collier, DeSoto, Glades and 13 more8 hr
Nov 30, 3:53 PM ESTMesoscale DiscussionSPCBroward, Collier, Hendry, Martin, Miami-Dade, Monroe and 2 more2 hr

Nearby

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