Alert archive / Alabama / Mesoscale Discussions in 2012
Mesoscale Discussion 2223
The Storm Prediction Center issued this mesoscale discussion at Dec 25, 2012, 7:08 PM CST for 20 counties in Alabama; Jackson County, Mississippi. It was in force for 67 min.
The area
The outline as issued.
The facts
- Issued
- Dec 25, 2012, 7:08 PM CST (01:08 UTC)
- Expired
- Dec 25, 2012, 8:15 PM CST
- In force
- 67 min
- Issued by
- the Storm Prediction Center
All 21 counties
Autauga County, AL, Baldwin County, AL, Butler County, AL, Chilton County, AL, Clarke County, AL, Clay County, AL, Conecuh County, AL, Coosa County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Lowndes County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Randolph County, AL, Shelby County, AL, Talladega County, AL, Tallapoosa County, AL, Wilcox County, AL, Jackson County, MS
The radar
The Birmingham radar (KBMX), 126 km from the middle of the area, began a volume at 01:10 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, 1.1 hours before the alert went out and 126 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.
175
ACUS11 KWNS 260109
SWOMCD
SPC MCD 260108
GAZ000-ALZ000-FLZ000-MSZ000-LAZ000-260215-
MESOSCALE DISCUSSION 2223
NWS STORM PREDICTION CENTER NORMAN OK
0708 PM CST TUE DEC 25 2012
AREAS AFFECTED...FAR SERN LA/MS...SWRN TO CNTRL AL
CONCERNING...TORNADO WATCH 695...696...
VALID 260108Z - 260215Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 695...696...CONTINUES.
SUMMARY...TORNADO WATCH 695 AND SEVERE THUNDERSTORM WATCH 697 ARE
SET TO EXPIRE AT 02Z. PORTIONS OF THESE WW/S WILL BE REPLACED OR
LOCALLY EXTENDED AS COORDINATION WITH AFFECTED WFO/S OCCURS PRIOR TO
EXPIRATION.
DISCUSSION...LONG-LIVED QLCS EXTENDED FROM NEAR BHM TO JUST E OF MSY
AT 01Z...PROGRESSING EWD AROUND 30-35 KT. THIS LINE SHOULD ATTEMPT
TO ACCELERATE BY LATE EVENING AS 700 MB JET INTENSIFIES EWD ALONG
THE LINE...YIELDING INCREASING DAMAGING WIND POTENTIAL...PRIMARILY
ALONG AND S OF THE SURFACE WARM FRONT FROM NEAR MGM TO ABY. HERE
TO...AN ISOLATED SIGNIFICANT TORNADO RISK STILL EXISTS IN THE
NEAR-TERM AND SHOULD LARGELY EVOLVE INTO WW 696 GIVEN 0-1 KM SHEAR
OF 40-45 KT.
FARTHER N...DOWNSTREAM AIR MASS IS NOT PARTICULARLY UNSTABLE N OF
THE FRONT PER SURFACE OBSERVATIONS AND 00Z BMX RAOB...BUT GIVEN THE
DEGREE OF FORCING AND KINEMATIC PROFILES...A THREAT FOR DAMAGING
WINDS SHOULD PERSIST ACROSS CNTRL AL INTO PARTS OF WRN GA /DETAILED
IN MCD 2221/.
..GRAMS.. 12/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FFC...BMX...MOB...LIX...
LAT...LON 30058938 30878846 32278743 33248682 33538658 33718627
33728582 33518532 33118522 31858642 30708735 30318751
30058938SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 25, 6:05 PM CST | Mesoscale Discussion | SPC | Bibb, Chambers, Chilton, Clay, Coosa, Elmore and 5 more | 85 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, 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.