A late season snow event took place over Iowa during the day on the 5th.  Strong low pressure developed over Kansas on the 4th and advanced northeast into northwest Missouri by the early morning hours of the 5th.  The low then moved east-southeast to be over southern Illinois by the evening of the 5th.  A strong push of warm and relatively moist air took place ahead of the low, while cold air moved in on the back side of the surface low.  Initially, precipitation with the system was in the form of rain showers and isolated thunderstorms.  The airmass was unstable with showalter indices around -4 C. across the south half of the state.  As the cold air settled southeast, the rain changed over to snow from the northwest with a brief period of ice pellets occurring during the changeover.  Once the rain changed over to snow it became heavy with visibility reduced to one quarter of a mile or less at many locations.  At the same time, northeast to north winds of 25 to 35 MPH with higher gusts accompanied the snow.  Temperatures remained at or a little above freezing during the event, which limited the amount of blowing snow.  During the late morning and early afternoon hours, a line of thunderstorms developed in the deformation band snow between Story City and Waterloo.  Reports of snowfall rates of over 5 inches per hour were received.  As the storms moved across Interstate 35 north of Story City, 3 inches of snow fell in a 30 minute period.  This resulted in numerous accidents and subsequently a 18 mile long section of the interstate was closed for a period of 3 hours due to gridlock.  The interstate was closed north of Story City to U.S. Highway 20.  A band of 6 to 10 inches of snowfall took place in the thunderstorm area from near Boone in Boone County to Conrad in Grundy County.  Some of the heavier snowfall totals included over 10 inches in Grundy County at Conrad, 10 inches in Hardin County at Eldora, 8 to 9 inches in Hamilton County at Jewell, and around 7 inches in Hardin County west of Iowa Falls, Hamilton County south of Williams, and in Boone County south of the Boone Airport.  In addition to the numerous accidents caused by the heavy, wet snow, scattered power outages also occurred as the snow took down tree limbs in a few places.

Winter Storm in CARROLL, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Storm in GREENE, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Winter Storm in BOONE, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: NWS Employee

Winter Storm in GRUNDY, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BLACK HAWK, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Storm in STORY, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Storm in MARSHALL, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in TAMA, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 5.00K
Crop damage: 0.00K
Reported by: COOP Observer

Winter Storm in DALLAS, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in POLK, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Winter Storm in CRAWFORD, IOWA
From 05-APR-09 09:00:00 to 05-APR-09 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BREMER, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WRIGHT, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in FRANKLIN, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Winter Storm in BUTLER, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WEBSTER, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in HAMILTON, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Winter Storm in HARDIN, IOWA
From 05-APR-09 05:00:00 to 05-APR-09 15:00:00 (CST-6)
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Law Enforcement