Alert archive / Alabama / Severe Thunderstorm Watches in 2020
Severe Thunderstorm Watch 34
The Storm Prediction Center issued this severe thunderstorm watch at Feb 12, 2020, 4:34 PM CST for 28 counties in Alabama. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Feb 12, 2020, 4:34 PM CST (22:34 UTC)
- Expired
- Feb 12, 2020, 9:27 PM CST
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 28 counties
Bibb County, AL, Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL
The radar
The Birmingham radar (KBMX), 100 km from the middle of the area, began a volume at 22:34 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
- 5%
- Ten or more severe wind reports
- 60%
- One or more gusts of 65 knots or more
- 20%
- 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
- 70%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 12, 5:14 PM CST | Severe Thunderstorm Warning | BMX | Lamar | 30 min |
| Feb 12, 5:26 PM CST | Severe Thunderstorm Warning | BMX | Marion | 34 min |
| Feb 12, 5:29 PM CST | Severe Thunderstorm Warning | HUN | Lauderdale, Limestone | 31 min |
| Feb 12, 5:38 PM CST | Severe Thunderstorm Warning | BMX | Winston | 52 min |
| Feb 12, 6:05 PM CST | Severe Thunderstorm Warning | HUN | Limestone, Madison | 25 min |
| Feb 12, 6:30 PM CST | Severe Thunderstorm Warning | HUN | Jackson, Madison | 45 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
Birmingham, AL (KBMX), launched 12:00Z, 10.6 hours before the alert went out and 99 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
- 619 m above ground
- 0-6 km bulk shear
- 79 kt
- 0-1 km storm-relative helicity
- 377 m²/s²
- 0-3 km storm-relative helicity
- 424 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 |
|---|---|---|---|---|
| Feb 12, 1:46 PM CST | Mesoscale Discussion | SPC | Colbert, Fayette, Franklin, Lamar, Marion, Pickens | 119 min |
Nearby
Severe Thunderstorm Watches in Alabama, 2020Every severe thunderstorm 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.