A very strong low pressure system lifted northeast from north central Nebraska into east central South Dakota during the evening of the 9th.  The system was very dynamic, being a negatively tilted trough in the mid and upper levels of the atmosphere.  A strong gradient was in place across Iowa, with winds of 75 kts within two thousand feet of the surface.  The dry slot lifted across the state and strong winds formed in the subsidence region.  An area of showers rotated into the dry slot over the northwest third of the state.  The rain resulted in cooling in the low levels through evaporational cooling to help bring the winds down to the surface.  In addition a few areas around the rest of the state reported breakthrough winds near high wind category.  One location was in Marion County at Pella, where a 59 MPH wind gust was recorded.  Another break through area occurred in Polk County in Ankeny, where high winds resulted in minor damage to a house there.  The greatest area of high winds was in a band about 40 to 50 miles wide extending from northeast of Denison, northeast into Hancock County.  Sustained winds of 30 to 35 MPH were recorded, with gusts of near 60 MPH at several locations.  Two semi-tractortrailer trucks were overturned by the winds.  One was near Britt, in Hancock County, the other near Thompson in Winnebago County.

High Wind in POLK, IOWA
From 09-FEB-09 22:30:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: NWS Employee

High Wind in HANCOCK, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Broadcast Media

High Wind in POCAHONTAS, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

High Wind in WRIGHT, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

High Wind in SAC, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 51.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in HUMBOLDT, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in CARROLL, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: AWOS

High Wind in MARION, IOWA
From 09-FEB-09 22:30:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 51.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in CALHOUN, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

High Wind in WEBSTER, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 52.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

High Wind in KOSSUTH, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

High Wind in WINNEBAGO, IOWA
From 09-FEB-09 18:00:00 to 09-FEB-09 23:30:00 (CST-6)
Magnitude: 50.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Broadcast Media