Alert archive / Florida / Tornado Watches in 2009

Tornado Watch 153

April 13, 200928 counties in Florida; 8 counties in Georgia

The Storm Prediction Center issued this tornado watch at Apr 13, 2009, 6:53 PM EDT for 28 counties in Florida; 8 counties in Georgia. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 13, 2009, 6:53 PM EDT (22:53 UTC)
Expired
Apr 13, 2009, 11:42 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 36 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Calhoun County, FL, Clay County, FL, Columbia County, FL, Dixie County, FL, Duval County, FL, Flagler 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, Levy County, FL, Liberty County, FL, Madison County, FL, Marion County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Wakulla County, FL, Brooks County, GA, Camden County, GA, Charlton County, GA, Clinch County, GA, Echols County, GA, Lanier County, GA, Lowndes County, GA, Ware County, GA

The radar

The Tallahassee radar (KTLH), 84 km from the middle of the area, began a volume at 22:55 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 13, 7:16 PM EDTSevere Thunderstorm WarningTAEJefferson, Taylor44 min
Apr 13, 7:25 PM EDTTornado WarningTAETaylor50 min
Apr 13, 7:28 PM EDTFlash Flood WarningTAEJefferson, Taylor107 min
Apr 13, 7:38 PM EDTSevere Thunderstorm WarningJAXClay, Duval, Saint Johns23 min
Apr 13, 7:40 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Clay, Putnam23 min
Apr 13, 8:00 PM EDTSevere Thunderstorm WarningTAEDixie, Lafayette, Madison, Taylor60 min
Apr 13, 8:24 PM EDTSevere Thunderstorm WarningJAXGilchrist, Suwannee47 min
Apr 13, 8:42 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Clay, Putnam33 min
Apr 13, 8:50 PM EDTSevere Thunderstorm WarningJAXAlachua, Columbia, Gilchrist, Hamilton40 min
Apr 13, 9:06 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Columbia, Gilchrist, Marion, Union26 min
Apr 13, 10:00 PM EDTTornado WarningJAXSaint Johns30 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 12:00Z, 10.9 hours before the alert went out and 82 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 12:00Z on 2009-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 138 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, Tallahassee Rgnl, FL at 12:00Z on 2009-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 391 square meters per square second.19395878Sfc1 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
138 J/kg
Mixed-layer CIN
-213 J/kg
Mixed-layer LCL
619 m above ground
0-6 km bulk shear
63 kt
0-1 km storm-relative helicity
391 m²/s²
0-3 km storm-relative helicity
472 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 11:42 PM EDTMesoscale DiscussionSPCEscambia, Okaloosa, Santa Rosa93 min
Apr 13, 12:01 AM EDTTornado WatchSPCEscambia, Okaloosa, Santa Rosa4 hr
Apr 13, 2:57 AM EDTMesoscale DiscussionSPCBay, Calhoun, Escambia, Gadsden, Gulf, Holmes and 6 more63 min
Apr 13, 3:33 AM EDTTornado WatchSPCBay, Calhoun, Escambia, Holmes, Jackson, Okaloosa and 3 more7 hr
Apr 13, 5:32 AM EDTMesoscale DiscussionSPCEscambia, Holmes, Okaloosa, Santa Rosa, Walton58 min
Apr 13, 8:27 AM EDTMesoscale DiscussionSPCCalhoun, Escambia, Gadsden, Holmes, Jackson, Leon and 5 more2 hr
Apr 13, 10:12 AM EDTTornado WatchSPCBay, Calhoun, Dixie, Escambia, Franklin, Gadsden and 14 more9 hr
Apr 13, 12:15 PM EDTMesoscale DiscussionSPCBaker, Bay, Bradford, Calhoun, Columbia, Dixie and 23 more90 min
Apr 13, 12:32 PM EDTTornado WatchSPCBaker, Bradford, Clay, Columbia, Duval, Gilchrist and 5 more6 hr
Apr 13, 6:22 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 18 more83 min
Apr 13, 6:52 PM EDTMesoscale DiscussionSPCCatoosa, Chattooga, Dade, Walker, Whitfield53 min

Nearby

Tornado Watches in Florida, 2009Tornado Watches in Georgia, 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; radar from the NEXRAD Level II archive.