An intense low pressure area moved southeast from Winnipeg through the upper Great Lakes during the early morning hours of the 12th, through the day.  The low was 985 mb and set up a tight pressure gradient across Iowa.  Very warm air was drawn north ahead of the low pressure systems trailing cold front, setting the stage for an adiabatic atmosphere.  The vorticity center tracked southeast through Wisconsin as the 500 mb jet ribbon set up over Iowa.  Strong winds began before sunrise and reached high wind criteria by the mid to late morning hours.  Winds blew through much of the day with sustained winds of 35 to 45 MPH reported in most areas.  Scattered gusts were above 50 kts, or 58 MPH.  Winds approached 60 MPH in Calhoun County at Farnhamville and in the Mason City areas.  Damage to trees and gutters was reported in the Cedar Falls area in Black Hawk County.  The strongest winds was at Brooklyn in Poweshiek County with a gust recorded at 64 MPH.  A gust of 60 MPH was measured southwest of Mason City.  The WFO in Johnston reported a 59 MPH wind gust in Polk County.  To the north, in Story County, in what was reported as the largest tent structure ever built, high winds totally destroyed a demonstration tent.

High Wind in HAMILTON, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in CERRO GORDO, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 52 MG
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in POWESHIEK, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 56 MG
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in POLK, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 51 MG
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in CALHOUN, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 50 MG
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in KOSSUTH, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in MARSHALL, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 40 MS
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WEBSTER, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WINNEBAGO, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in BREMER, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in GRUNDY, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in STORY, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 37 ES
Property damage: 150K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in TAMA, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in JASPER, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in EMMET, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 MS
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in HUMBOLDT, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in FRANKLIN, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in BLACK HAWK, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 52 EG
Property damage: 75K
Reported by: TRAINED SPOTTER

High Wind in BOONE, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in HANCOCK, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in HARDIN, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 50 MG
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in PALO ALTO, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in POCAHONTAS, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in BUTLER, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WORTH, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 ES
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC

High Wind in WRIGHT, IOWA
From 12-DEC-04 10:00:00 to 12-DEC-04 17:00:00 (CST)
Magnitude: 35 MS
Property damage: 50K
Reported by: AWOS,ASOS,MESONET,ETC