Alert archive / Alabama / Mesoscale Discussions in 2012

Mesoscale Discussion 141

February 22, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Feb 22, 2012, 2:08 PM CST for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Feb 22, 2012, 2:08 PM CST (20:08 UTC)
Expired: Feb 22, 2012, 4:15 PM CST
In force: 2 hr
Issued by: the Storm Prediction Center

All 88 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Cleburne County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Dade County, GA, Dawson County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Lumpkin County, GA, Murray County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Towns County, GA, Union County, GA, Walker County, GA, White County, GA, Whitfield County, GA, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Itawamba County, MS, Kemper County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Noxubee County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Tishomingo County, MS, Union County, MS, Webster County, MS, Winston County, MS, Cherokee County, NC, Clay County, NC, Graham County, NC, Bledsoe County, TN, Bradley County, TN, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Lincoln County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Polk County, TN, Rhea County, TN, Sequatchie County, TN

The radar

The Columbus AFB radar (KGWX), 87 km from the middle of the area, began a volume at 20:08 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, 8.1 hours before the alert went out and 89 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 27 J/kg
Mixed-layer CIN: -92 J/kg
Mixed-layer LCL: 635 m above ground
0-6 km bulk shear: 86 kt
0-1 km storm-relative helicity: 134 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

408 
ACUS11 KWNS 222009
SWOMCD
SPC MCD 222008
GAZ000-NCZ000-TNZ000-ALZ000-MSZ000-222215-

MESOSCALE DISCUSSION 0141
NWS STORM PREDICTION CENTER NORMAN OK
0208 PM CST WED FEB 22 2012

AREAS AFFECTED...PARTS OF NRN NS...THE NRN HALF OF AL...PARTS OF SRN
TN...NWRN GA...FAR WRN NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 222008Z - 222215Z

CONTINUED AIRMASS DESTABILIZATION SUGGESTS INCREASING POTENTIAL FOR
SEVERE STORMS THIS AFTERNOON.  WW WILL BE POSSIBLE IN THE NEXT 1-2
HOURS.

LATEST VISIBLE SATELLITE IMAGERY PAIRED WITH SURFACE AND OBJECTIVE
ANALYSES REVEAL A CLEARLY DESTABILIZING BOUNDARY LAYER...BENEATH
WHAT HAS BEEN A PERSISTENT CAPPING INVERSION.  AS THE BOUNDARY LAYER
CONTINUES TO WARM/SLOWLY MOISTEN...THE EWD SPREAD OF COOLER
AIR/STEEPER LAPSE RATES ALOFT ASSOCIATED WITH THE WEAK UPPER TROUGH
NOW PROGRESSING ACROSS THE MID MS VALLEY WILL RESULT IN ADDITIONAL
DESTABILIZATION OVER THE NEXT FEW HOURS.

WHILE A LOW-LEVEL FOCUS FOR STORM DEVELOPMENT REMAINS DIFFICULT TO
DISCERN -- AND THUS LOCATION OF A CONCENTRATED THREAT AREA REMAINS
UNCERTAIN...INCREASINGLY STRONG/VEERING FLOW WITH HEIGHT IS
PROVIDING A KINEMATIC ENVIRONMENT SUPPORTIVE OF ORGANIZED/ROTATING
STORMS.  THIS -- AND THE INCREASINGLY FAVORABLE THERMODYNAMICS --
SUGGEST THAT ANY STORMS WHICH CAN DEVELOP WILL LIKELY
ORGANIZE/INTENSIFY...WITH DAMAGING WINDS AND HAIL POSSIBLE ALONG
WITH SOME ISOLATED TORNADO POTENTIAL.

ATTM...CU FIELD APPEARS MOST ROBUST ACROSS NERN MS AND EWD ACROSS
NRN AL AND INTO THE SRN APPALACHIANS.  WITH THIS AREA ON THE NRN
FRINGE OF THE BETTER THERMODYNAMIC ENVIRONMENT AND NEAR THE SRN
BOUNDARY OF STRONGER UPPER FORCING ASSOCIATED WITH THE PROGRESSING
WAVE...THIS AREA APPEARS ATTM TO BE THE MOST LIKELY INITIATION ZONE
FOR INITIAL CONVECTION.

..GOSS.. 02/22/2012

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

ATTN...WFO...GSP...MRX...FFC...OHX...BMX...HUN...MEG...JAN...

LAT...LON   32728894 32918977 33399003 34588919 35638555 35588375
            34828331 32988640 32688806 32728894

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 22, 5:49 PM CST	Mesoscale Discussion	SPC	Blount, Cullman, DeKalb, Etowah, Jackson, Lawrence and 6 more	86 min

Nearby

Mesoscale Discussions in Alabama, 2012 Mesoscale Discussions in Georgia, 2012 Mesoscale Discussions in Mississippi, 2012 Every 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.