Alert archive / Alabama / Mesoscale Discussions in 2012

Mesoscale Discussion 77

January 26, 201211 counties in Alabama; 9 counties in Mississippi; Lawrence County, Tennessee

The Storm Prediction Center issued this mesoscale discussion at Jan 26, 2012, 5:35 PM CST for 11 counties in Alabama; 9 counties in Mississippi; Lawrence County, Tennessee. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Jan 26, 2012, 5:35 PM CST (23:35 UTC)
Expired
Jan 26, 2012, 6:30 PM CST
In force
55 min
Issued by
the Storm Prediction Center
All 21 counties

Colbert County, AL, Fayette County, AL, Franklin County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Marion County, AL, Pickens County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Alcorn County, MS, Clay County, MS, Itawamba County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Noxubee County, MS, Prentiss County, MS, Tishomingo County, MS, Lawrence County, TN

The radar

The Columbus AFB radar (KGWX), 48 km from the middle of the area, began a volume at 23:36 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 nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 11.6 hours before the alert went out and 157 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.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2012-01-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 274 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 12:00Z on 2012-01-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
274 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
478 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

283 
ACUS11 KWNS 262335
SWOMCD
SPC MCD 262335 
ALZ000-TNZ000-MSZ000-270030-

MESOSCALE DISCUSSION 0077
NWS STORM PREDICTION CENTER NORMAN OK
0535 PM CST THU JAN 26 2012

AREAS AFFECTED...NERN MS/NWRN AL/MIDDLE TN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 262335Z - 270030Z

THUNDERSTORMS CAPABLE OF SMALL HAIL AND GUSTY WINDS WILL BE POSSIBLE
OVER THE NEXT HOUR OR TWO...BEFORE QUICKLY DIMINISHING AFTER DARK.
DUE TO THE BRIEF/MARGINAL NATURE...A WW SHOULD NOT BE NEEDED.

AN AREA OF CLEARING OCCURRING BEHIND A SQUALL LINE /NOW LOCATED IN
WRN GA AND THE CNTRL FL PANHANDLE/ HAS SUPPORTED MARGINAL
DESTABILIZATION ACROSS A SMALL CORRIDOR IN NERN MS AND AL. FORCING
FOR ASCENT...IN COMBINATION WITH SURFACE CONVERGENCE IS SUPPORTING A
SMALL LINE OF THUNDERSTORMS THAT MAY BE CAPABLE OF SMALL HAIL AND
GUSTY WINDS...GIVEN COOLING MIDLEVEL TEMPERATURES AND THE MAGNITUDE
OF STRONGER FLOW PERSISTING ACROSS THE AREA. VERY WEAK INSTABILITY
WILL GENERALLY LIMIT MORE SIGNIFICANT SEVERE POTENTIAL...WHILE
DIURNAL COOLING QUICKLY LEADS TO STABILIZATION...FURTHER LIMITING
SEVERE POTENTIAL SHORTLY.

..HURLBUT.. 01/26/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OHX...BMX...HUN...MEG...JAN...

LAT...LON   34858700 33708727 32888774 32768852 33368879 34298879
            34898866 35178834 35248739 34858700

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 26, 2:05 AM CSTMesoscale DiscussionSPCMobile, Washington2 hr
Jan 26, 4:18 AM CSTTornado WatchSPCBaldwin, Choctaw, Clarke, Conecuh, Escambia, Mobile and 3 more7 hr
Jan 26, 7:29 AM CSTMesoscale DiscussionSPCBaldwin, Choctaw, Clarke, Conecuh, Escambia, Mobile and 3 more91 min
Jan 26, 9:34 AM CSTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bullock, Butler, Calhoun and 24 more86 min
Jan 26, 9:55 AM CSTTornado WatchSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 34 more7 hr
Jan 26, 2:16 PM CSTMesoscale DiscussionSPCBarbour, Dale, Henry, Houston, Lee, Russell119 min
Jan 25, 8:23 PM CSTMesoscale DiscussionSPCAmite, Jefferson Davis, Lawrence, Lincoln, Marion, Pike and 2 more97 min

Nearby

Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Tennessee, 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.