Alert archive / Alabama / Mesoscale Discussions in 2007

Mesoscale Discussion 2113

October 18, 200742 counties in Alabama; 5 counties in Florida; George County, Mississippi

The Storm Prediction Center issued this mesoscale discussion at Oct 18, 2007, 3:52 PM CDT for 42 counties in Alabama; 5 counties in Florida; George County, Mississippi. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Oct 18, 2007, 3:52 PM CDT (20:52 UTC)
Expired: Oct 18, 2007, 5:15 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center

All 48 counties

Autauga County, AL, Baldwin County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Butler County, AL, Calhoun County, AL, Chambers County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Clay County, AL, Coffee County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Etowah County, AL, Geneva County, AL, Hale County, AL, Jefferson County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Randolph County, AL, Russell County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tallapoosa County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, George County, MS

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 8.9 hours before the alert went out and 137 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: 234 J/kg
Mixed-layer CIN: -85 J/kg
Mixed-layer LCL: 632 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 246 m²/s²
0-3 km storm-relative helicity: 331 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 182052
SWOMCD
SPC MCD 182052 
FLZ000-ALZ000-MSZ000-182215-

MESOSCALE DISCUSSION 2113
NWS STORM PREDICTION CENTER NORMAN OK
0352 PM CDT THU OCT 18 2007

AREAS AFFECTED...SRN/ERN AL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 182052Z - 182215Z

TRENDS ARE BEING MONITORED CLOSELY FOR THE POSSIBILITY OF AN
ADDITIONAL WW.

BROKEN BAND OF STORMS SEEM TO BE ADVANCING EAST OF INITIATING
LOW-LEVEL CONFLUENCE ZONE OVER EASTERN MISSISSIPPI...AIDED BY 30-40
KT SOUTHWESTERLY MEAN ENVIRONMENTAL FLOW.  WITH SOUTHEASTERLY STORM
RELATIVE INFLOW EMANATING FROM RAIN-COOLED AIR MASS ASSOCIATED WITH
WEAKENING CONVECTIVE CLUSTER OVER THE EASTERN GULF COAST REGION...
THE LONGEVITY OF ONGOING STORMS PROGRESSING EAST OF THE MISSISSIPPI
BORER INTO WESTERN ALABAMA IS IN QUESTION.  IT WOULD APPEAR THAT
WEAKENING TRENDS MAY ENSUE WITH EASTWARD PROGRESSION.  BUT...UNTIL
THIS OCCURS...SIZABLE LOW-LEVEL HODOGRAPHS BENEATH A 30+ KT
SOUTHWESTERLY 850 MB JET STREAK WILL REMAIN SUPPORTIVE OF ISOLATED
TORNADO POTENTIAL.

..KERR.. 10/18/2007

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

ATTN...WFO...TAE...BMX...HUN...MOB...LIX...

30648874 31508856 32348817 32938762 33818669 34438604
33158531 32208517 31148542 30508576 30318779

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 18, 3:02 AM CDT	Mesoscale Discussion	SPC	Baldwin, Choctaw, Clarke, Conecuh, Escambia, Marengo and 4 more	58 min
Oct 18, 10:26 AM CDT	Mesoscale Discussion	SPC	Colbert, Franklin, Lamar, Lauderdale, Lawrence, Limestone and 2 more	2 hr
Oct 18, 11:15 AM CDT	Mesoscale Discussion	SPC	Baldwin	90 min
Oct 18, 1:31 PM CDT	Tornado Watch	SPC	Colbert, Cullman, Fayette, Franklin, Greene, Hale and 13 more	9 hr
Oct 18, 5:39 PM CDT	Mesoscale Discussion	SPC	Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 4 more	66 min
Oct 17, 7:09 PM CDT	Tornado Watch	SPC	Adams, Attala, Bolivar, Carroll, Choctaw, Claiborne and 45 more	7 hr
Oct 18, 12:27 AM CDT	Mesoscale Discussion	SPC	Alcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 28 more	93 min
Oct 18, 1:31 AM CDT	Tornado Watch	SPC	Alcorn, Benton, Coahoma, DeSoto, Lafayette, Marshall and 7 more	4 hr
Oct 18, 4:08 AM CDT	Mesoscale Discussion	SPC	Alcorn, Benton, Coahoma, DeSoto, Lafayette, Lee and 8 more	67 min

Nearby

Mesoscale Discussions in Alabama, 2007 Mesoscale Discussions in Florida, 2007 Mesoscale Discussions in Mississippi, 2007 Every mesoscale discussion in 2007

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.