Alert archive / Florida / Tornado Watches in 2007
Tornado Watch 675
The Storm Prediction Center issued this tornado watch at Sep 20, 2007, 11:19 PM EDT for 18 counties in Florida. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 20, 2007, 11:19 PM EDT (03:19 UTC)
- Expired
- Sep 21, 2007, 6:47 AM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
Counties Alachua County, FL, Bradford County, FL, Columbia County, FL, Dixie County, FL, Gilchrist County, FL, Hamilton County, FL, Lafayette County, FL, Lake County, FL, Levy County, FL, Madison County, FL, Marion County, FL, Orange County, FL, Putnam County, FL, Seminole County, FL, Sumter County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL
The radar
The Jacksonville radar (KJAX), 144 km from the middle of the area, began a volume at 03:21 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
- 10%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 5%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 30%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 11:28 PM EDT | Severe Thunderstorm Warning | JAX | Marion | 47 min |
| Sep 20, 11:51 PM EDT | Tornado Warning | JAX | Alachua | 39 min |
| Sep 21, 12:14 AM EDT | Severe Thunderstorm Warning | JAX | Marion | 46 min |
| Sep 21, 12:30 AM EDT | Severe Thunderstorm Warning | JAX | Alachua | 45 min |
| Sep 21, 1:00 AM EDT | Severe Thunderstorm Warning | JAX | Marion, Putnam | 45 min |
| Sep 21, 1:24 AM EDT | Severe Thunderstorm Warning | JAX | Alachua, Bradford | 51 min |
| Sep 21, 1:51 AM EDT | Severe Thunderstorm Warning | JAX | Putnam | 39 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 00:00Z, 3.3 hours before the alert went out and 146 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
- 2537 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 634 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 23 m²/s²
- 0-3 km storm-relative helicity
- 70 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.5
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 20, 10:56 PM EDT | Mesoscale Discussion | SPC | Alachua, Baker, Bradford, Citrus, Clay, Columbia and 13 more | 94 min |
| Sep 21, 2:35 AM EDT | Mesoscale Discussion | SPC | Alachua, Baker, Bradford, Columbia, Dixie, Franklin and 13 more | 115 min |
| Sep 21, 11:45 AM EDT | Mesoscale Discussion | SPC | Bay, Calhoun, Franklin, Gulf, Liberty, Wakulla and 1 more | 60 min |
| Sep 21, 5:37 PM EDT | Mesoscale Discussion | SPC | Bay, Calhoun, Escambia, Gadsden, Gulf, Holmes and 9 more | 53 min |
| Sep 21, 5:58 PM EDT | Tornado Watch | SPC | Bay, Calhoun, Franklin, Gadsden, Gulf, Holmes and 10 more | 7 hr |
Nearby
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.