Alert archive / Georgia / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 104

March 24, 201213 counties in Florida; 29 counties in Georgia

The Storm Prediction Center issued this severe thunderstorm watch at Mar 24, 2012, 10:45 AM EDT for 13 counties in Florida; 29 counties in Georgia. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Mar 24, 2012, 10:45 AM EDT (14:45 UTC)
Expired
Mar 24, 2012, 7:00 PM EDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 42 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Clay County, FL, Columbia County, FL, Duval County, FL, Gilchrist County, FL, Hamilton County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Suwannee County, FL, Union County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Brantley County, GA, Bryan County, GA, Bulloch County, GA, Camden County, GA, Candler County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Echols County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glynn County, GA, Jeff Davis County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Montgomery County, GA, Pierce County, GA, Tattnall County, GA, Toombs County, GA, Treutlen County, GA, Ware County, GA, Wayne County, GA, Wheeler County, GA

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 24, 10:59 AM EDTSevere Thunderstorm WarningJAXAtkinson, Coffee46 min
Mar 24, 11:10 AM EDTSevere Thunderstorm WarningJAXColumbia, Hamilton, Suwannee50 min
Mar 24, 11:27 AM EDTSevere Thunderstorm WarningJAXAtkinson, Bacon, Coffee, Pierce, Ware48 min
Mar 24, 11:56 AM EDTSevere Thunderstorm WarningJAXBaker49 min
Mar 24, 12:17 PM EDTSevere Thunderstorm WarningCHSEffingham58 min
Mar 24, 12:23 PM EDTSevere Thunderstorm WarningCHSEvans, Tattnall53 min
Mar 24, 2:48 PM EDTSevere Thunderstorm WarningJAXBaker42 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

Jacksonville, FL (KJAX), launched 12:00Z, 2.8 hours before the alert went out and 107 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, Jacksonville, FL at 12:00Z on 2012-03-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 139 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, Jacksonville, FL at 12:00Z on 2012-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.193958Sfc1 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
139 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
982 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 10:16 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 8 more59 min
Mar 24, 12:29 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 4 more61 min
Mar 24, 4:19 PM EDTMesoscale DiscussionSPCBaker, Bradford, Clay, Columbia, Duval, Hamilton and 4 more86 min
Mar 24, 6:25 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 11 more65 min
Mar 24, 4:16 PM EDTMesoscale DiscussionSPCRichmond59 min
Mar 24, 5:52 PM EDTMesoscale DiscussionSPCChattooga, Dade, Walker53 min

Nearby

Severe Thunderstorm Watches in Georgia, 2012Severe Thunderstorm Watches in Florida, 2012Every severe thunderstorm watch in 2012

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.