Alert archive / Florida / Tornado Watches in 2020
Tornado Watch 507
The Storm Prediction Center issued this tornado watch at Nov 11, 2020, 8:04 AM EST for 9 counties in Florida. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Nov 11, 2020, 8:04 AM EST (13:04 UTC)
- Expired
- Nov 11, 2020, 5:00 PM EST
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Strongest gust expected
- 60 kt
Counties Charlotte County, FL, Collier County, FL, DeSoto County, FL, Hardee County, FL, Hillsborough County, FL, Lee County, FL, Manatee County, FL, Pinellas County, FL, Sarasota County, FL
The radar
The Tampa radar (KTBW), 135 km from the middle of the area, began a volume at 13:04 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
- 5%
- 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
- 20%
Warnings issued inside it
13 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 11, 11:54 AM EST | Tornado Warning | TBW | Manatee, Sarasota | 20 min |
| Nov 11, 12:21 PM EST | Tornado Warning | TBW | Pinellas | 24 min |
| Nov 11, 12:24 PM EST | Tornado Warning | TBW | Hillsborough, Manatee | 21 min |
| Nov 11, 12:44 PM EST | Tornado Warning | TBW | Pinellas | 16 min |
| Nov 11, 12:50 PM EST | Tornado Warning | MFL | Broward, Collier, Hendry, Palm Beach | 25 min |
| Nov 11, 12:50 PM EST | Tornado Warning | TBW | Hillsborough, Pinellas | 25 min |
| Nov 11, 1:13 PM EST | Tornado Warning | TBW | Pinellas | 11 min |
| Nov 11, 1:53 PM EST | Severe Thunderstorm Warning | MFL | Collier, Miami-Dade, Monroe | 22 min |
| Nov 11, 2:13 PM EST | Severe Thunderstorm Warning | MFL | Broward, Collier, Hendry, Miami-Dade, Monroe | 47 min |
| Nov 11, 2:55 PM EST | Severe Thunderstorm Warning | MFL | Collier, Miami-Dade, Monroe | 65 min |
| Nov 11, 4:40 PM EST | Tornado Warning | TBW | Manatee, Sarasota | 20 min |
| Nov 11, 4:54 PM EST | Severe Thunderstorm Warning | MFL | Collier, Miami-Dade, Monroe | 36 min |
| Nov 11, 4:58 PM EST | Tornado Warning | TBW | Hillsborough, Manatee, Pinellas, Sarasota | 32 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
Tampa Bay, FL (KTBW), launched 12:00Z, 1.1 hours before the alert went out and 135 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
- 87 J/kg
- Mixed-layer CIN
- -42 J/kg
- Mixed-layer LCL
- 985 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 122 m²/s²
- 0-3 km storm-relative helicity
- 124 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 11, 4:36 AM EST | Mesoscale Discussion | SPC | Charlotte, Collier, Lee, Monroe | 2 hr |
| Nov 11, 11:56 AM EST | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Hardee, Hillsborough, Lee and 2 more | 2 hr |
| Nov 11, 2:14 PM EST | Mesoscale Discussion | SPC | Broward, Glades, Monroe, Palm Beach | 61 min |
| Nov 11, 4:01 PM EST | Mesoscale Discussion | SPC | Charlotte, Collier, DeSoto, Hardee, Hillsborough, Lee and 3 more | 59 min |
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.