Alert archive / Mississippi / Mesoscale Discussions in 2009

Mesoscale Discussion 2168

October 30, 200920 counties in Alabama; 48 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Oct 30, 2009, 2:11 PM CDT for 20 counties in Alabama; 48 counties in Mississippi. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued: Oct 30, 2009, 2:11 PM CDT (19:11 UTC)
Expired: Oct 30, 2009, 3:45 PM CDT
In force: 94 min
Issued by: the Storm Prediction Center

All 68 counties

Choctaw County, AL, Clarke County, AL, Colbert County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Marengo County, AL, Marion County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Washington County, AL, Winston County, AL, Alcorn County, MS, Attala County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Greene County, MS, Itawamba County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lafayette County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Lee County, MS, Lincoln County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Perry County, MS, Pike County, MS, Pontotoc County, MS, Prentiss County, MS, Rankin County, MS, Scott County, MS, Simpson County, MS, Smith County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Walthall County, MS, Wayne County, MS, Webster County, MS, Winston County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 128 km from the middle of the area, began a volume at 19:12 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.

Tornado Watch 786Oct 30, 5:20 PM CDT

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 7.2 hours before the alert went out and 135 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: 471 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 595 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 268 m²/s²
0-3 km storm-relative helicity: 311 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 3.5

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 30, 10:22 AM CDT	Mesoscale Discussion	SPC	Pickens	83 min
Oct 30, 12:22 PM CDT	Tornado Watch	SPC	Choctaw, Clarke, Colbert, Cullman, Fayette, Franklin and 15 more	8 hr
Oct 30, 4:57 PM CDT	Mesoscale Discussion	SPC	Choctaw, Clarke, Colbert, Fayette, Franklin, Greene and 12 more	93 min
Oct 30, 5:20 PM CDT	Tornado Watch	SPC	Autauga, Bibb, Blount, Butler, Calhoun, Chilton and 29 more	3 hr
Oct 30, 2:03 AM CDT	Mesoscale Discussion	SPC	Adams, Benton, Bolivar, Carroll, Claiborne, Coahoma and 21 more	57 min

Nearby

Mesoscale Discussions in Mississippi, 2009 Mesoscale Discussions in Alabama, 2009 Every mesoscale discussion in 2009

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.