Tornado Outbreak March 12 2006

The following is a chronological listing of the tornadoes which have been confirmed thus far for March 12^th, with the time and location of the initial touchdown and Fujita rating.

Time Location County F-Scale

820 am CST Linwood Leavenworth F0

912 am CST Sibley to Orrick to S of Richmond Jackson & Ray F1

950 am CST 2 WSW Carrollton Carroll F0

1046 am CST 1 N Huntsville to NE of Moberly Randolph F0

227 pm CST Amsterdam Bates F0

350 pm CST 2 NE La Monte to S of Blackwater Pettis & Cooper F0

350 pm CST 2 E Calhoun to 4 SSE Green Ridge Henry & Pettis F1

412 pm CST 5 SW Sedalia to just SW of Smithton Pettis F2*

417 pm CST Just W of Otterville Cooper F0

430 pm CST 2 SW Fayette Howard F0

751 pm CST 3 NE Warrensburg to 4 W Houstonia Johnson & Pettis F0

752 pm CST Butler to 3 SE Blairstown Bates & Henry F2 *

807 pm CST 4 S Sweet Springs to 2 E Marshall Saline F2

819 pm CST 3 S Marshall to 4 N Arrow Rock to Saline & Howard F3

2 E Armstrong

825 pm CST 3 NE Napton to 4 N Arrow Rock Saline F0

840 pm CST 2 NE Leeton to just S of Johnson & Pettis F2

La Monte

910 pm CST 5 SSW Moberly to just S of Randolph F3*

Renick to the county line

* These tornadoes were the ones that resulted in fatalities.

These 17 tornadoes were confirmed by damage surveys out of a preliminary count of 32 tornado reports received into the National Weather Service on Sunday. A total of 201 large hail and/or damaging wind reports were also received into the National Weather Service office in Pleasant Hill, from locations across much of western and central Missouri, and adjacent northeast Kansas. Virtually every county of the 44 served by the Pleasant Hill office experienced a severe thunderstorm on Sunday.

The initial round of four tornadoes (shaded in red on the map posted on the Pleasant Hill web site) formed from a supercell thunderstorm that moved through a rather cold and dry airmass at ground level. The temperature at the Kansas City International Airport, at the time of the tornado near Linwood), was in the lower 40s. Much warmer air existed aloft though, that allowed the storm to produce intermittent tornadoes from the northwest side of the Kansas City metro area, east-northeast into central Missouri. The storm also produced extensive hail and wind damage as it cycled, or reorganized, and moved across the Northland. The most intense tornado from supercell storm struck along the Missouri River near Sibley, then tracked east-northeast through Orrick in Ray County. F1 damage was confirmed in this area by an NWS survey team.

The second round of tornadoes (shaded in blue on the map) occurred during the mid-afternoon hours. Further assessment has brought the number of tornadoes from this round of storms back to six, as what was thought to be one tornado from eastern Henry County through western Cooper County actually ended up being three tornadoes. The most significant tornado from the afternoon round touched down at approximately 4:12 pm in far southwest Pettis County, then moved east-northeast across southern Pettis County before dissipating. This tornado produced F2 damage to several structures south and southeast of Sedalia. One of the tornado fatalities occurred with a resident attempting to evacuate a mobile home to the south of Sedalia. The other tornadoes from the second round include a F0 tornado which affected areas from Amsterdam to near Adrian in Bates County. Damage was noted to the Amsterdam Fire Department. A third touchdown was noted by spotters just northeast of La Monte in Pettis County (this would be a second storm north of the one that produced the F2 south of Sedalia). This tornado moved northeast, crossed I-70 and then dissipated just east of Blackwater in Cooper County. Damage from this tornado caused traffic problems along I-70 west of Boonville for a time. A brief F0 tornado also touched down briefly southwest of Fayette in Howard County, at around 4:25 pm.

A separate tornado was rated with the Pettis County storm further south and west, from the F2 tornado track. This tornado touched down in eastern Henry County, tracked across far northwest Benton County, and re-entered Pettis County before dissipating around 4:05 pm. This storm then cycled and produced the other Pettis County F2 tornado detailed above. The last tornado from this storm, a brief F0 touchdown, was observed just west of Otterville. An aerial damage survey found evidence of tornado damage in this location as well.

The final round of seven tornadoes (shaded in green) struck the region after sunset Sunday evening. These tornadoes also were the most intense of the outbreak, and also the most dangerous as they occured after dark. Two distinct supercell thunderstorms produced this series of tornadoes from Johnson County, Missouri, northeast through Saline, Howard and Randolph Counties.

The first tornado of this round struck near Butler (in Bates County) around 7:52 pm, then moved northeast to areas west and north of Urich in Henry County around 8:10 pm to 8:15 pm. F2 damage was noted north of Urich, and this tornado took the life of a man north of Urich. This tornado dissipated just southeast of Blairstown in northern Henry County around 8:25 pm. A second tornado formed from this supercell storm approximately three miles northeast of Leeton (in Johnson County, Missouri) around 8:40 pm. The tornado tracked across eastern Johnson County to the south of Whiteman Air Force Base (AFB), then dissipated to the southwest of La Monte in Pettis County. Damage of F2 intensity was noted south of Whiteman AFB, where roofs were completely removed from several frame houses along Y Highway.

The remaining tornadoes formed from the second supercell storm. The first tornado from this supercell touched down approximately 3 miles northeast of Warrensburg around 7:54 pm. The tornado moved northeast, producing F0 damage through northeast Johnson and northwest Pettis Counties. The tornado lifted briefly south of Sweet Springs, but a new tornado track again along this same path approximately 3 miles southeast of Sweet Springs. The tornado intensified near I-70, and produced F2 damage just northeast of I-70 near Exit 71, where several houses lost their roofs. A semi was also blown on top of cars, where motorists were attempting to seek shelter under the overpass. Highway overpasses are not safe locations to seek shelter from a tornado, and several injuries were noted in this location as evidence of this truth. This tornado moved northeast and then turned more north, crossing U.S. Highway 65 approximately 3 miles south of Marshall, missing the county seat by just a few miles before dissipating east of Marshall around 8:23 pm. A third tornado actually formed south of the second tornado near U.S. 65 south of Marshall, and for a time two tornadoes were on the ground simultaneously about 2 to 3 miles apart. Photographs from this area are quite similar to the Palm Sunday tornado outbreak of 1965. As the second tornado dissipated east of Marshall, a fourth tornado touched down at 8:25 pm west of Arrow Rock. Based on anecdotal observations by spotters and chasers, this tornado merged with tornado #3 and this led to a strengthening of the third tornado (similar to what occurred on March 13, 1990 east of Hesston, KS) and quickly led to the third tornado becoming over a quarter mile wide and intensifying to F3 strength. F3 damage was noted near the Missouri River to a farmstead.

The third tornado from this northern supercell (now just one on the ground) passed north of Arrow Rock and produced F2 damage to the northwest of Fayettte. The last tornado associated with this supercell developed to the south-southwest of Moberly, or just to the east of Higbee, in far southern Randolph County, at approximately 9:10 pm. The tornado moved northeast to just south of Renick, where F2 damage was noted to several homes and mobile homes. This tornado took the lives of four Randolph County residents. The tornado produced F3 damage where a farmhouse was destroyed, just before it moved northeast and into Monroe County. Details on the Monroe County portion of this tornado track can be found on the St. Louis NWS web site.

A preliminary tally of tornado reports received on Sunday across the United States March 12-13 can be found at http://www.spc.noaa.gov/climo. Additional details on the Fujita-Pearson damage scale can be found at http://www.spc.noaa.gov/faq/tornado/f-scale.html.