Alert archive / Alabama / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 168
The Storm Prediction Center issued this severe thunderstorm watch at Apr 26, 2017, 11:02 PM CDT for 22 counties in Alabama. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2017, 11:02 PM CDT (04:02 UTC)
- Expired
- Apr 27, 2017, 5:00 AM CDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 22 counties
Autauga County, AL, Bibb County, AL, Chilton County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lowndes County, AL, Marengo County, AL, Marion County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL
The radar
The Birmingham radar (KBMX), 80 km from the middle of the area, began a volume at 04:01 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
- 10%
- 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
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
4 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 27, 12:06 AM CDT | Severe Thunderstorm Warning | BMX | Sumter | 39 min |
| Apr 27, 12:07 AM CDT | Tornado Warning | BMX | Pickens | 25 min |
| Apr 27, 12:33 AM CDT | Severe Thunderstorm Warning | BMX | Greene | 42 min |
| Apr 27, 12:56 AM CDT | Severe Thunderstorm Warning | BMX | Sumter | 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
Birmingham, AL (KBMX), launched 00:00Z, 4.0 hours before the alert went out and 79 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
- 1641 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 51 m²/s²
- 0-3 km storm-relative helicity
- 86 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 |
|---|---|---|---|---|
| Apr 27, 1:36 AM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Chilton, Choctaw, Clarke, Dallas and 11 more | 114 min |
| Apr 27, 9:42 AM CDT | Mesoscale Discussion | SPC | Barbour, Bullock, Coffee, Covington, Dale, Pike and 1 more | 2 hr |
| Apr 27, 12:30 PM CDT | Mesoscale Discussion | SPC | Barbour, Russell | 90 min |
| Apr 27, 3:23 PM CDT | Mesoscale Discussion | SPC | Barbour, Henry, Lee, Russell | 97 min |
| Apr 27, 6:26 PM CDT | Mesoscale Discussion | SPC | Barbour, Bullock, Crenshaw, Pike, Russell | 64 min |
Nearby
Severe Thunderstorm Watches in Alabama, 2017Every severe thunderstorm watch in 2017
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.