Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 2222
The Storm Prediction Center issued this mesoscale discussion at Dec 25, 2012, 6:05 PM CST for 11 counties in Alabama. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Dec 25, 2012, 6:05 PM CST (00:05 UTC)
- Expired
- Dec 25, 2012, 7:30 PM CST
- In force
- 85 min
- Issued by
- the Storm Prediction Center
Counties Bibb County, AL, Chambers County, AL, Chilton County, AL, Clay County, AL, Coosa County, AL, Elmore County, AL, Jefferson County, AL, Randolph County, AL, Shelby County, AL, Talladega County, AL, Tallapoosa County, AL
The radar
The Birmingham radar (KBMX), 38 km from the middle of the area, began a volume at 00:05 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, 0.1 hours before the alert went out and 39 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
- 22 J/kg
- Mixed-layer CIN
- -78 J/kg
- Mixed-layer LCL
- 563 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 696 m²/s²
- 0-3 km storm-relative helicity
- 921 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.5
The text
As transmitted, in the capitals the NWS used until 2016.
464
ACUS11 KWNS 260005
SWOMCD
SPC MCD 260005
ALZ000-260130-
MESOSCALE DISCUSSION 2222
NWS STORM PREDICTION CENTER NORMAN OK
0605 PM CST TUE DEC 25 2012
AREAS AFFECTED...CNTRL AL
CONCERNING...SEVERE THUNDERSTORM WATCH 697...
VALID 260005Z - 260130Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 697
CONTINUES.
SUMMARY...DAMAGING WIND THREAT MAY INCREASE ACROSS SRN PORTIONS OF
WW 697 THROUGH 02Z.
DISCUSSION...NRN PORTION OF LONG-LIVED QLCS HAD LOST ITS MORE
PROMINENT BOWING STRUCTURE COMPARED TO 1-2 HOURS AGO. ALTHOUGH
CONVECTION IS ROOTED ABOVE THE PBL...AN OBSERVED WIND GUST OF 28 KT
WAS SAMPLED BY THE TCL ASOS. DESPITE THE WEAK ELEVATED BUOYANCY AND
COOL SURFACE TEMPERATURES DOWNSTREAM /MIDDLE TO UPPER 50S/...MERGING
OF THE QLCS WITH THE PRE-FRONTAL CONFLUENCE BAND MAY YIELD AN UPTICK
IN CONVECTIVE INTENSITY ON THE NOSE OF THE 700 MB JET. A RETURN TO A
PERSISTENT BOWING STRUCTURE APPEARS PROBABLE...MOVING OUT OF WW 695
INTO THE SRN PORTION OF WW 697 IN THE NEXT HOUR...WITH AN ASSOCIATED
THREAT FOR DAMAGING WINDS.
..GRAMS.. 12/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BMX...
LAT...LON 33498746 33698695 33608591 33308540 33028530 32798534
32578550 32568612 32698710 32848757 33498746SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 25, 7:08 PM CST | Mesoscale Discussion | SPC | Autauga, Baldwin, Butler, Chilton, Clarke, Clay and 14 more | 67 min |
| Dec 25, 8:49 PM CST | Mesoscale Discussion | SPC | Barbour, Bullock, Coffee, Covington, Crenshaw, Dale and 9 more | 56 min |
| Dec 25, 9:23 PM CST | Tornado Watch | SPC | Baldwin, Barbour, Bullock, Chambers, Coffee, Covington and 12 more | 6 hr |
| Dec 25, 11:10 PM CST | Mesoscale Discussion | SPC | Barbour, Dale, Geneva, Henry, Houston, Lee and 1 more | 95 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.