Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 463
The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2012, 3:46 PM CDT for 13 counties in Alabama. It was in force for 59 min.
The area
The outline as issued.
The facts
- Issued
- Apr 5, 2012, 3:46 PM CDT (20:46 UTC)
- Expired
- Apr 5, 2012, 4:45 PM CDT
- In force
- 59 min
- Issued by
- the Storm Prediction Center
Counties Blount County, AL, Calhoun County, AL, Cullman County, AL, Etowah County, AL, Fayette County, AL, Jefferson County, AL, Lamar County, AL, Marion County, AL, Pickens County, AL, St. Clair County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL
The radar
The Birmingham radar (KBMX), 84 km from the middle of the area, began a volume at 20:46 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 12:00Z, 8.8 hours before the alert went out and 83 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
- 315 J/kg
- Mixed-layer CIN
- -31 J/kg
- Mixed-layer LCL
- 754 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- -91 m²/s²
- 0-3 km storm-relative helicity
- -43 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -1.5
The text
As transmitted, in the capitals the NWS used until 2016.
179 ACUS11 KWNS 052046 SWOMCD SPC MCD 052046 ALZ000-052145- MESOSCALE DISCUSSION 0463 NWS STORM PREDICTION CENTER NORMAN OK 0346 PM CDT THU APR 05 2012 AREAS AFFECTED...PORTIONS OF NRN/CNTRL AL CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 052046Z - 052145Z THREAT FOR ISOLATED DAMAGING WINDS AND POSSIBLY LARGE HAIL MAY INCREASE DURING THE NEXT FEW HRS FOR PORTIONS OF NRN/CNTRL AL. ATTM...A NEW WW DOES NOT APPEAR NECESSARY. POTENT MIDLEVEL VORTICITY LOBE IS BEGINNING TO ACCELERATE EWD INTO NRN MS. LOOSELY ORGANIZED MCS IS OCCURRING COINCIDENT WITH THIS MIDLEVEL FEATURE IN AN ENVIRONMENT CHARACTERIZED BY TEMPERATURES IN THE LOW TO MID 70S AND DEWPOINTS IN THE MID 50S. THOUGH MLCAPE VALUES ARE ONLY AROUND 500 J/KG PER OBJECTIVE ANALYSIS GUIDANCE...STEEP LOW-LEVEL LAPSE RATES MAY AID IN AN ISOLATED DAMAGING WIND THREAT AS THE MCS MOVES INTO CNTRL/NRN AL. ..GARNER.. 04/05/2012 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...BMX...HUN... LAT...LON 34318814 34298579 33828565 33348648 33258827 34318814
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 5, 7:36 AM CDT | Mesoscale Discussion | SPC | Choctaw, Greene, Hale, Marengo, Perry, Pickens and 2 more | 54 min |
| Apr 5, 9:14 AM CDT | Severe Thunderstorm Watch | SPC | Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 34 more | 8 hr |
| Apr 5, 10:41 AM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Butler, Chilton, Choctaw, Clarke and 15 more | 94 min |
| Apr 5, 12:09 PM CDT | Mesoscale Discussion | SPC | Colbert, Cullman, Franklin, Lauderdale, Lawrence, Limestone and 4 more | 96 min |
| Apr 5, 1:12 PM CDT | Mesoscale Discussion | SPC | Barbour, Bullock, Chambers, Clay, Coffee, Covington and 11 more | 93 min |
| Apr 5, 1:21 PM CDT | Severe Thunderstorm Watch | SPC | Colbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more | 8 hr |
| Apr 5, 1:58 PM CDT | Severe Thunderstorm Watch | SPC | Coffee, Dale, Geneva, Henry, Houston | 6 hr |
| Apr 5, 3:06 PM CDT | Mesoscale Discussion | SPC | Colbert, DeKalb, Franklin, Jackson, Lauderdale, Lawrence and 4 more | 54 min |
| Apr 5, 3:49 PM CDT | Mesoscale Discussion | SPC | Geneva, Henry, Houston | 86 min |
| Apr 5, 6:14 PM CDT | Severe Thunderstorm Watch | SPC | Autauga, Bibb, Blount, Bullock, Calhoun, Chambers and 21 more | 3 hr |
| Apr 5, 6:15 PM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Blount, Bullock, Calhoun, Chambers and 23 more | 45 min |
Nearby
Mesoscale Discussions in Alabama, 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.