An Alberta Clipper type low pressure passed to the north of Iowa during the day on the 11th as the vorticity center slid southeast across the area passing just northeast of Iowa.  Very strong northwest winds were in place in the mid and upper levels of the atmosphere.  Wind speeds were 130 kts between 9 and 10 km ASL, with 60 to 70 kt winds extending downward to within 1.5 km of the surface.  A strong cold front dropped southeast across the state during the afternoon.  Strong subsidence behind he front transported the stronger winds down to the surface for a period of a few hours.  Winds were sustained in the 35 to 45 MPH range with occasional gusts of 60 to 65 MPH.  An interesting thing with this event was the occurrence of the first convective system of the season.  A line of thunderstorms developed just to the southwest of the vorticity center along the cold frontal boundary.  As the cold front mentioned above moved southeast, a narrow line of thunderstorms developed along the front.  The line was very fast moving.  Combined with the already strong ambient winds, very strong gusts occurred with the line along with whiteout conditions in brief heavy snow and blowing snow.  It was fortunate that there was no significant existing snow cover in Iowa.  If there had there would have been a significant blizzard event.  Though visibility was reduced to near zero with the thunderstorms, the period of visibility reduction was under 30 minutes.  The strongest wind occurred in Franklin County at Latimer where a 74 MPH wind gust was recorded at 1352 CST.  Wind were estimated at 70 MPH in Cerro  Gordo County in  Mason City proper at 1330 CST.  The winds downed two large parking lot light poles.  Wind gusts to around 75 MPH overturned 9 semi-tractortrailer trucks near Mason City on U.S. Highway 65.  The winds also blew down several utility poles as well.  Winds gusted to 60 MPH or more in the greater Waterloo area as the line passed.  In Black Hawk County, the ASOS site at the Waterloo Airport recorded a 69 MPH wind gust with the passage of the thunderstorms at 1434 CST.  Thunderstorms also produced 60 MPH winds at 1415 CST in Butler County as they moved through the Clarksville area.  High winds in Bremer County blew down a barn near the town of Tripoli.  Overall, damage was light with the event due to the fact that it occurred during the cold season since the trees were bare.

High Wind in HAMILTON, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in HANCOCK, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in HARDIN, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in HUMBOLDT, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in KOSSUTH, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 51 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in PALO ALTO, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 52 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in POCAHONTAS, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in RINGGOLD, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in SAC, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WEBSTER, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WINNEBAGO, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WORTH, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WRIGHT, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 53 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in BLACK HAWK, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 60 M
Property damage: 10K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in BUTLER, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 52 M
Property damage: 7K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in EMMET, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in FRANKLIN, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 64 M
Property damage: 10K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in CALHOUN, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 52 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in GRUNDY, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in CERRO GORDO, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 65 E
Property damage: 100K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in CARROLL, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 55 M
Property damage: 5K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in BREMER, IOWA
From 11-FEB-03 13:15:00 to 11-FEB-03 16:00:00 (CST)
Magnitude: 50 M
Property damage: 45K
Reported by: AWOS,ASOS,MESONET,ETC