A Severe Thunderstorm Warning was issued a few minutes ago and will be in effect until 5:30 for northern Lyon County in NW Iowa. Here is the official warning from the NWS in Sioux Falls.
BULLETIN – EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SIOUX FALLS SD
443 PM CDT WED AUG 27 2008

THE NATIONAL WEATHER SERVICE IN SIOUX FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR…
NORTHERN LYON COUNTY IN NORTHWEST IOWA
SOUTHERN ROCK COUNTY IN SOUTHWEST MINNESOTA

* UNTIL 530 PM CDT

* AT 444 PM CDT…NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING NICKEL SIZE HAIL. THIS
STORM WAS LOCATED 4 MILES SOUTHWEST OF LARCHWOOD…OR 9 MILES
NORTHEAST OF CANTON…MOVING NORTHEAST AT 34 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR…
LESTER…HILLS AROUND 455 PM CDT…
ROCK RAPIDS AROUND 505 PM CDT…

THIS STORM HAS A HISTORY OF PRODUCING LARGE HAIL. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS.

Only a few other showers and thunderstorms were around mainly located east of the present severe storm.