Alert archive / Georgia / Severe Thunderstorm Watches in 2009
Severe Thunderstorm Watch 99
The Storm Prediction Center issued this severe thunderstorm watch at Mar 31, 2009, 5:25 PM EDT for 8 counties in Florida; 14 counties in Georgia. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2009, 5:25 PM EDT (21:25 UTC)
- Expired
- Apr 1, 2009, 12:00 AM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 22 counties
Baker County, FL, Columbia County, FL, Duval County, FL, Gilchrist County, FL, Hamilton County, FL, Nassau County, FL, Suwannee County, FL, Union County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Brantley County, GA, Camden County, GA, Charlton County, GA, Clinch County, GA, Coffee County, GA, Echols County, GA, Glynn County, GA, Jeff Davis 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- 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
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 5:46 PM EDT | Severe Thunderstorm Warning | JAX | Atkinson, Coffee, Jeff Davis | 44 min |
| Mar 31, 7:43 PM EDT | Severe Thunderstorm Warning | JAX | Hamilton, Suwannee | 62 min |
| Mar 31, 8:38 PM EDT | Tornado Warning | JAX | Hamilton, Suwannee | 52 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, 9.4 hours before the alert went out and 186 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2169 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 243 m²/s²
- 0-3 km storm-relative helicity
- 172 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 12:32 PM EDT | Mesoscale Discussion | SPC | Escambia, Holmes, Okaloosa, Santa Rosa, Walton | 88 min |
| Mar 31, 2:05 PM EDT | Severe Thunderstorm Watch | SPC | Bay, Calhoun, Dixie, Escambia, Franklin, Gadsden and 14 more | 8 hr |
| Mar 31, 4:15 PM EDT | Mesoscale Discussion | SPC | Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 10 more | 90 min |
| Mar 31, 5:17 PM EDT | Mesoscale Discussion | SPC | Baker, Bradford, Clay, Columbia, Duval, Nassau and 2 more | 28 min |
| Mar 31, 6:12 PM EDT | Mesoscale Discussion | SPC | Bay, Calhoun, Escambia, Gadsden, Gulf, Holmes and 11 more | 93 min |
| Mar 31, 7:59 PM EDT | Mesoscale Discussion | SPC | Baker, Columbia, Hamilton, Jefferson, Lafayette, Leon and 5 more | 91 min |
Nearby
Severe Thunderstorm Watches in Georgia, 2009Severe Thunderstorm Watches in Florida, 2009Every severe thunderstorm 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.