Alert archive / Georgia / Tornado Watches in 2009
Tornado Watch 810
The Storm Prediction Center issued this tornado watch at Dec 25, 2009, 3:46 AM EST for 14 counties in Florida; 19 counties in Georgia. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 25, 2009, 3:46 AM EST (08:46 UTC)
- Expired
- Dec 25, 2009, 11:00 AM EST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 33 counties
Alachua County, FL, Baker County, FL, Bradford County, FL, Columbia County, FL, Dixie County, FL, Gilchrist County, FL, Hamilton County, FL, Jefferson County, FL, Lafayette County, FL, Levy County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Berrien County, GA, Brantley County, GA, Brooks County, GA, Camden County, GA, Charlton County, GA, Clinch County, GA, Coffee County, GA, Cook County, GA, Echols County, GA, Glynn County, GA, Jeff Davis County, GA, Lanier County, GA, Lowndes County, GA, Pierce County, GA, Ware County, GA, Wayne County, GA
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 30%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- 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
- 80%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 25, 5:20 AM EST | Severe Thunderstorm Warning | TAE | Madison | 25 min |
| Dec 25, 5:34 AM EST | Severe Thunderstorm Warning | JAX | Hamilton | 56 min |
| Dec 25, 6:58 AM EST | Severe Thunderstorm Warning | JAX | Hamilton, Suwannee | 36 min |
| Dec 25, 7:33 AM EST | Severe Thunderstorm Warning | JAX | Columbia, Hamilton, Suwannee | 42 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, 8.8 hours before the alert went out and 108 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.
- Mixed-layer CAPE
- 1 J/kg
- Mixed-layer CIN
- -94 J/kg
- Mixed-layer LCL
- 909 m above ground
- 0-6 km bulk shear
- 61 kt
- 0-1 km storm-relative helicity
- 500 m²/s²
- 0-3 km storm-relative helicity
- 677 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
502
WWUS20 KWNS 250851
SEL0
SPC WW 250851
FLZ000-GAZ000-CWZ000-251600-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 810
NWS STORM PREDICTION CENTER NORMAN OK
350 AM EST FRI DEC 25 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
NORTHERN AND WESTERN FLORIDA
SOUTHERN GEORGIA
COASTAL WATERS
EFFECTIVE THIS FRIDAY MORNING FROM 350 AM UNTIL 1100 AM EST.
TORNADOES...HAIL TO 0.5 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 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH NORTHWEST OF
WAYCROSS GEORGIA TO 65 MILES SOUTH SOUTHWEST OF CROSS CITY
FLORIDA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).
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...NNE/SSW-ORIENTED BAND OF PRE-FRONTAL TSTMS OVER SW
GA...THE ERN FL PANHANDLE...AND THE NERN GULF HAS INCREASED IN THE
PAST HOUR. THE INCREASE MAY REFLECT A COMBINATION OF FACTORS
INCLUDING /1/ GLANCING INFLUENCE OF STRONG UPR IMPULSE NOW ENTERING
AL.../2/ GREATER LOW LVL MOISTURE RELATIVE TO POINTS WEST...AND /3/
HEATING FROM WARM LOOP CURRENT WATERS. AT ANY RATE...ASSUMING THE
UPSWING PERSISTS...COMBINATION OF SUSTAINED STORMS IN ENVIRONMENT OF
STRONG 0-6 KM SHEAR WITH A CONSIDERABLE LOW-LVL DIRECTIONAL
COMPONENT SUGGESTS POTENTIAL FOR TORNADOES/LOCALLY DMGG WIND.
AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 21045.
...CORFIDISPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 24, 8:32 PM EST | Mesoscale Discussion | SPC | Bay, Calhoun, Holmes, Jackson, Okaloosa, Walton and 1 more | 118 min |
| Dec 24, 10:45 PM EST | Mesoscale Discussion | SPC | Bay, Calhoun, Franklin, Gadsden, Gulf, Jackson and 4 more | 2 hr |
| Dec 25, 3:27 AM EST | Mesoscale Discussion | SPC | Alachua, Baker, Citrus, Columbia, Dixie, Gilchrist and 7 more | 63 min |
| Dec 25, 7:27 AM EST | Mesoscale Discussion | SPC | Baker, Columbia, Dixie, Gilchrist, Hamilton, Lafayette and 3 more | 93 min |
| Dec 25, 4:41 AM EST | Mesoscale Discussion | SPC | Appling, Bryan, Bulloch, Burke, Camden, Candler and 24 more | 64 min |
| Dec 25, 5:01 AM EST | Tornado Watch | SPC | Bryan, Bulloch, Burke, Candler, Chatham, Dodge and 20 more | 9 hr |
| Dec 25, 10:26 AM EST | Mesoscale Discussion | SPC | Appling, Bacon, Brantley, Camden, Charlton, Glynn and 3 more | 64 min |
| Dec 25, 11:39 AM EST | Mesoscale Discussion | SPC | Bryan, Chatham, Effingham, Liberty, McIntosh | 66 min |
Nearby
Tornado Watches in Georgia, 2009Tornado Watches in Florida, 2009Every tornado watch in 2009
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.