Alert archive / Mississippi / Mesoscale Discussions in 2005

Mesoscale Discussion 557

April 11, 200516 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 11, 2005, 1:17 PM CDT for 16 counties in Mississippi. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Apr 11, 2005, 1:17 PM CDT (18:17 UTC)
Expired: Apr 11, 2005, 2:15 PM CDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Alcorn County, MS, Benton County, MS, Coahoma County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Yalobusha County, MS

The radar

The Columbus AFB radar (KGWX), 103 km from the middle of the area, began a volume at 18:17 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 152Apr 11, 1:35 PM CDT

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 6.3 hours before the alert went out and 79 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: 530 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 522 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 5.3

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
Apr 11, 3:56 AM CDT	Mesoscale Discussion	SPC	Attala, Carroll, Claiborne, Copiah, Hinds, Holmes and 10 more	64 min
Apr 11, 6:17 AM CDT	Mesoscale Discussion	SPC	DeSoto, Tunica	118 min
Apr 11, 9:41 AM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Carroll, Claiborne, Copiah and 23 more	2 hr
Apr 11, 10:15 AM CDT	Tornado Watch	SPC	Adams, Bolivar, Calhoun, Carroll, Chickasaw, Claiborne and 14 more	9 hr
Apr 11, 12:12 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Carroll, Claiborne, Copiah and 23 more	2 hr
Apr 11, 1:35 PM CDT	Tornado Watch	SPC	Alcorn, Benton, Calhoun, Chickasaw, Itawamba, Lafayette and 10 more	5 hr
Apr 11, 1:41 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Claiborne, Copiah, Covington, Franklin and 15 more	2 hr
Apr 11, 2:05 PM CDT	Tornado Watch	SPC	Amite, Attala, Choctaw, Clarke, Clay, Copiah and 28 more	7 hr
Apr 11, 6:35 PM CDT	Tornado Watch	SPC	Forrest, George, Greene, Hancock, Harrison, Jackson and 3 more	4 hr
Apr 11, 6:52 PM CDT	Mesoscale Discussion	SPC	Amite, Attala, Choctaw, Clay, Copiah, Covington and 23 more	83 min

Nearby

Mesoscale Discussions in Mississippi, 2005 Every mesoscale discussion in 2005

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.