Alert archive / Florida / Tornado Watches in 2020
Tornado Watch 489
The Storm Prediction Center issued this tornado watch at Sep 15, 2020, 6:45 AM CDT for Baldwin County, Mobile County, Alabama; 13 counties in Florida. It was in force for 11 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 15, 2020, 6:45 AM CDT (11:45 UTC)
- Expired
- Sep 15, 2020, 6:00 PM CDT
- In force
- 11 hr
- Issued by
- the Storm Prediction Center
- Strongest gust expected
- 60 kt
Counties Baldwin County, AL, Mobile County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Franklin County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Wakulla County, FL, Walton County, FL, Washington County, FL
The radar
The Eglin Afb radar (KEVX), 96 km from the middle of the area, began a volume at 11:45 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
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 10%
- One or more gusts of 65 knots or more
- 10%
- 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
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 15, 10:54 AM CDT | Flash Flood Warning | TAE | Bay | 31 hr |
| Sep 15, 12:27 PM CDT | Flash Flood Warning | TAE | Walton | 22 hr |
| Sep 15, 3:35 PM CDT | Flash Flood Warning | MOB | Baldwin | 8 hr |
| Sep 15, 3:56 PM CDT | Flash Flood Warning | TAE | Bay, Holmes, Walton, Washington | 30 hr |
| Sep 15, 4:36 PM CDT | Flash Flood Warning | MOB | Okaloosa, Santa Rosa | 7 hr |
| Sep 15, 5:09 PM CDT | Flash Flood Warning | MOB | Mobile | 8 hr |
| Sep 15, 5:49 PM CDT | Flash Flood Warning | MOB | Baldwin | 5 hr |
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, 11.8 hours before the alert went out and 252 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
- 288 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 831 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- 62 m²/s²
- 0-3 km storm-relative helicity
- 61 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted.
686 WWUS20 KWNS 151142 SEL9 SPC WW 151142 ALZ000-FLZ000-CWZ000-152300- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 489 NWS Storm Prediction Center Norman OK 640 AM CDT Tue Sep 15 2020 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southwestern Alabama Florida Panhandle Coastal Waters * Effective this Tuesday morning and evening from 640 AM until 600 PM CDT. * Primary threats include... A couple tornadoes possible SUMMARY...The tornado threat with Hurricane Sally will increase in immediate coastal areas through the remainder of the morning. The threat then should shift gradually northward/inland this afternoon, as Sally's center very slowly approaches landfall, based on the National Hurricane Center forecast. The tornado watch area is approximately along and 30 statute miles north and south of a line from 5 miles south of Mobile AL to 45 miles east of Panama City FL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 12045. ...Edwards
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 15, 6:17 AM CDT | Mesoscale Discussion | SPC | Baldwin, Conecuh, Covington, Escambia, Geneva, Mobile | 2 hr |
| Sep 15, 10:15 AM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile | 3 hr |
| Sep 15, 2:16 PM CDT | Mesoscale Discussion | SPC | Baldwin, Escambia, Mobile | 119 min |
| Sep 15, 5:23 PM CDT | Mesoscale Discussion | SPC | Escambia | 2 hr |
| Sep 15, 5:48 PM CDT | Tornado Watch | SPC | Baldwin | 12 hr |
Nearby
Tornado Watches in Florida, 2020Tornado Watches in Alabama, 2020Every tornado watch in 2020
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.