Alert archive / Florida / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 70
The Storm Prediction Center issued this severe thunderstorm watch at Mar 28, 2011, 2:43 AM EDT for 18 counties in Florida. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 28, 2011, 2:43 AM EDT (06:43 UTC)
- Expired
- Mar 28, 2011, 5:53 AM EDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Alachua County, FL, Baker County, FL, Bradford County, FL, Columbia County, FL, Dixie County, FL, Franklin County, FL, Gilchrist County, FL, Hamilton County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Levy County, FL, Madison County, FL, Marion County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Wakulla County, FL
The radar
The Tallahassee radar (KTLH), 105 km from the middle of the area, began a volume at 06:45 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
- 20%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- 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
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 28, 3:08 AM EDT | Severe Thunderstorm Warning | JAX | Alachua, Gilchrist | 52 min |
| Mar 28, 3:41 AM EDT | Severe Thunderstorm Warning | TAE | Taylor | 49 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, 6.7 hours before the alert went out and 103 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
- 1716 J/kg
- Mixed-layer CIN
- -11 J/kg
- Mixed-layer LCL
- 717 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km storm-relative helicity
- 71 m²/s²
- 0-3 km storm-relative helicity
- 137 m²/s²
- Significant tornado parameter
- 1.1
- Supercell composite
- 4.1
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 28, 1:59 AM EDT | Mesoscale Discussion | SPC | Alachua, Baker, Bradford, Columbia, Dixie, Gadsden and 11 more | 91 min |
| Mar 28, 6:31 AM EDT | Mesoscale Discussion | SPC | Charlotte, Collier, Glades, Hendry, Lee, Martin and 3 more | 59 min |
| Mar 28, 6:48 AM EDT | Severe Thunderstorm Watch | SPC | Broward, Charlotte, Collier, DeSoto, Glades, Hendry and 7 more | 5 hr |
| Mar 28, 5:49 PM EDT | Mesoscale Discussion | SPC | Broward, Charlotte, Collier, Hendry, Lee, Miami-Dade and 1 more | 56 min |
| Mar 28, 6:12 PM EDT | Mesoscale Discussion | SPC | Baker, Calhoun, Columbia, Gadsden, Gulf, Hamilton and 9 more | 63 min |
Nearby
Severe Thunderstorm Watches in Florida, 2011Every severe thunderstorm watch in 2011
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.