A volatile pattern was in place over the central U.S. with a strong long wave trough moving through the area.  On the 29th, a strong push of warm to record warm air moved over the state.  A piece of energy from the long wave trough moved northeast with the surface low passing through Iowa.  The cold front went through during the day with temperatures falling through the day.  The main part of the system pushed northeast out of the base of the trough during the night of the 29th into the day on the 30th.  Precipitation expanded across the state.  At first it fell as snow or a mixture of light rain and snow.  As colder air moved into the state, the rain changed over to all snow.  The system was quite dynamic and that was evident by satellite pictures showing a prominent deformation zone on the southwest part of the system.  This produced light to moderate snow to the southwest of Iowa through the night.  During the predawn and early morning hours, a speed max jet segment moved up the east side of the upper level trough and enhanced the snowfall rates.  Much of the snow from this event fell with the passage of the jet segment between 0400 and 0900 CST with snowfall rates of 1 to 2 inches per hour in a narrow band.   The heaviest snowfall occurred from Des Moines, northeast into the Waterloo area.  Waterloo reported 7.5 inches of snow, with Des Moines receiving 6.4 inches.  Six and one half inches fell in Poweshiek County near Grinnell, with 6 inches in Tama County near Toledo.  In addition to the snow, winds increased during the day as low pressure moved out of Missouri into the lower Great Lakes and intensified.  Sustained winds over 25 MPH were reported with frequent gusts in the 30 to 50 MPH range.  This caused considerable blowing and drifting of snow with local whiteout conditions.  Interstate 30 was closed north of Ames for several hours.  Accidents were numerous due to refreezing of water on the roads from the warm conditions initially.   Most schools closed and many businesses closed for the day because of the hazardous conditions.

Winter Storm in UNION, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in CASS, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in CLARKE, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in LUCAS, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in ADAIR, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BLACK HAWK, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BUTLER, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BREMER, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in MADISON, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WARREN, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in MARION, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in GUTHRIE, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in DALLAS, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in POLK, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in STORY, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in RINGGOLD, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in TAYLOR, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in ADAMS, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 10:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WAYNE, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in DECATUR, IOWA
From 29-JAN-13 22:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in MONROE, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in APPANOOSE, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in MAHASKA, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WAPELLO, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in HARDIN, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in POWESHIEK, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in JASPER, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in TAMA, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in MARSHALL, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in GRUNDY, IOWA
From 30-JAN-13 00:00:00 to 30-JAN-13 12:00:00 (CST-6)
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Trained Spotter