Posted at 2:09 PM on August 8, 2009
by Paul Huttner
NWS doppler radar loop at 2pm shows possible tornadic supercell with rotation and large hail moving toward northern Sioux Falls.
Update 3:15pm: It appears the severe threat has largely passed in Sioux Falls. Severe storms remain a threat in southwest Minnesota and northwest Iowa.
Batten down the hatches in and north of Sioux Falls. Tornado warnings are posted for this storm headed through early this afternoon. Southwest Minnesota towns in the Pipestone area should be on alert for this storm as we approach 3pm.
Additional storms are developing southwest of Sioux Falls and moving northeast. These storms are producing damaging winds and extreme hail up to grapefruit size.
FSD: Pipestone [Pipestone Co, MN] law enforcement reports HAIL of quarter size (E1.00 INCH) at 03:14 PM CDT --
FSD: 6 Ne Tyndall [Bon Homme Co, SD] trained spotter reports HAIL of baseball size (E2.75 INCH) at 02:40 PM CDT --
FSD: 1 W Montrose [Mccook Co, SD] storm chaser reports HAIL of golf ball size (E1.75 INCH) at 02:08 PM CDT --
FSD: 11 Ssw Mitchell [Davison Co, SD] amateur radio reports HAIL of grapefruit size (E4.00 INCH) at 12:45 PM CDT --