August 28th, 2008 Severe Wind and Tornado Event


Between 6:25 and 6:40 PM CDT, a continuous swath of damaging downburst winds and two weak tornadoes occurred over parts of southwest Shelby and far northern Monroe counties in northeast Missouri.  The damage was confined to a corridor about 1 mile wide from 1.5 miles south of Clarence to 6 miles southwest of Shelbina over north-central Monroe county.  Damage was mainly confined to silos, barns, power poles and numerous large trees.  A large bow echo system that moved across parts of northeast Missouri was responsible for the damaging winds and weak tornadoes over this area.  A second a smaller swath of continuous damaging downburst winds extended from 3/4 mile west of Bethel to just south of Bethel to 2 miles east-southeast of Bethel in northeast Shelby county Missouri.  Damage was confined to medium and large trees.  


 Tree and Structural Damage Along U.S 151 south of Clarence, Missouri
 (Click on image for a larger image).








Damage between County Roads 118 and 114 (Southeast of Clarence, MO) 
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 (Left) Tornado cuts through a line of large trees, (Center) Two of four silos destroyed, 3) remains of a barn.



 (Left) Scour marks from the tornado in a bean field, (Center) Parts of one silo thrown 1/3 mile to the southeast.




 (Left) One of two hog buildings damaged by the weak tornado; (Center) Two silos damaged; (Right) Debris from the silos tossed a 1/4 to 1/2 mile southeast from its original site.

 Reflectivity and Doppler velocity data from KLSX (STL)

(Far left) Radar reflectivity imagery for 6:32 PM CDT. (Near left) Base velocity for this same time. The reflectivity pattern shows a bow echo moving across southern Knox and Shelby counties. The corridor of damage shown on the damage map (above) occurred along the southern periphery of the storm's Rear Inflow Jet.  A small circulation likely formed along the leading edge of the line of storms and moved southeast aiding in the production of the damaging winds and weak tornadoes.  (Click on image for a larger image).



 (Far Left) Reflectivity at 6:41 PM CDT; (Near left) Base velocity data from KLSX at 6:41 PM CDT.  The bow echo at this time continues to move east-southeast at 40 to 45 mph. The narrow corridor of wind and tornadic damage continues along the southern periphery of the core of the storm's Rear Inflow Jet over far northern Monroe county MO.  While minor to moderate wind damage occurred in the vicinity of the core of the RIJ. is the U.S. government's official web portal to all federal, state and local government web resources and services.