Update: 9:20 pm. Series of Doppler radar images showing severe rotation west of Stewartville. The image below shows a reflectivity display. Note the extreme wind shear causing the tornadic cell to "tilt" over to one side, to the right of the general motion of upper level winds (west/northwest or 290 degrees).


Tornado watch for much of southern MN (does NOT include Twin Cities) until 1 am Thursday morning. At least 6 tornado touchdowns in Minnesota (as of 9:00 pm). The most notable: large, violent tornado hits the Austin area with reports of damage & injuries, possibly a "multi-vortex" tornado with multiple funnels rotating around a common center/wall cloud. The lingering threat is greatest east of Owatonna and Austin, toward Stewartville, Rochester, Cannon Falls and the Winona area. Residents of far southeastern MN should stay alert and stay tuned for possible warnings.
(Click on the image to bring it full screen and read the tornado warning text for the Owatonna area).

Update: 9:00 pm. Reports of a large, damaging tornado in the Austin area, and the threat is not over yet. Cars have been flipped over in the Austin area with injury reports and considerable debris. Power is out throughout the city. A "multivortex" tornado (several tornadoes all spinning around a common center) was observed with this supercell thunderstorm. Tornadoes often form in "families", one tornado touches down, matures and then dies out. Minutes later the same parent thunderstorm spawns a second tornado farther south/east, in the warm, humid air, unaffected by rain/hail-cooled air. This process can continue for many hours, resulting in multiple tornadoes from the same supercell thunderstorm.


Update: 8:45 pm. Very worried about Owatonna area: Doppler storm relative velocity field showing very strong rotation directly over the town - supercell has a long history of producting tornadoes/funnel clouds.


Update: 8:30 pm. Funnel clouds spotted near Waseca.

* Greatest tornado risk: Austin area. Large tornado on the ground, impacting northern/eastern suburbs of Austin area!

* Tornado warnings posted for southeastern MN counties through the evening hours.

* Greatest risk near Owatonna, Faribault, Austin and Rochester/Stewartville area.

* Strong/severe storms may move into the Twin Cities metro area later tonight - conditions ripe.

* Computer models print out some 1-2" rainfall amounts over the next few days, potential for tropical dew points.

* First Minnesota tornado of the year touches down in Wilkin county (far west central MN) around 4:40 pm. No reports of injuries/damage.

8:34 pm (Greatest threat appears to be just east/northeast of Austin, tornadic supercell moving toward Elkton and Dexter area).