Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 1657
The Storm Prediction Center issued this mesoscale discussion at Jul 30, 2012, 11:21 PM CDT for 11 counties in Alabama; 10 counties in Mississippi. It was in force for 114 min.
The area
The outline as issued.
The facts
- Issued
- Jul 30, 2012, 11:21 PM CDT (04:21 UTC)
- Expired
- Jul 31, 2012, 1:15 AM CDT
- In force
- 114 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 21 counties
Fayette County, AL, Franklin County, AL, Greene County, AL, Jefferson County, AL, Lamar County, AL, Marion County, AL, Pickens County, AL, Shelby County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Calhoun County, MS, Chickasaw County, MS, Clay County, MS, Itawamba County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS
The radar
The Columbus AFB radar (KGWX), 11 km from the middle of the area, began a volume at 04:23 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.
The watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Birmingham, AL (KBMX), launched 00:00Z, 4.4 hours before the alert went out and 155 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
- 771 J/kg
- Mixed-layer CIN
- -144 J/kg
- Mixed-layer LCL
- 1852 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 39 m²/s²
- 0-3 km storm-relative helicity
- 145 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.5
The text
As transmitted, in the capitals the NWS used until 2016.
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</html>SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 31, 1:02 AM CDT | Mesoscale Discussion | SPC | Bibb, Blount, Chilton, Cullman, Fayette, Hale and 10 more | 88 min |
| Jul 31, 1:23 AM CDT | Severe Thunderstorm Watch | SPC | Autauga, Bibb, Bullock, Chambers, Chilton, Clay and 19 more | 6 hr |
| Jul 31, 5:48 AM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Bullock, Chambers, Chilton, Clay and 19 more | 57 min |
| Jul 31, 7:47 AM CDT | Mesoscale Discussion | SPC | Choctaw, Clarke, Conecuh, Covington, Escambia, Geneva and 3 more | 58 min |
| Jul 31, 11:01 AM CDT | Mesoscale Discussion | SPC | Baldwin, Clarke, Mobile, Washington | 59 min |
Nearby
Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Mississippi, 2012Every mesoscale discussion in 2012
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.