A powerful storm system moved from the Southern Plains on Wednesday morning into Michigan by early Friday morning. This brought a potent winter storm  to eastern Iowa through the period. Precipitation began as rain on Wednesday evening and quickly changed over to snow along and north of a line from Keokuk County to Linn County to Johnson County to Dubuque County. North of this line snow continued to fall heavily  at times through the night while to the south mainly rain with isolated thunderstorms occurred. A powerful cold front swept through eastern Iowa on Thursday morning changing the precipitation over to all snow from west to east by noon. In addition, winds switched to the northwest and increased rapidly to 25 to 35 mph with gusts as high as 60 mph.  This created blizzard conditions across all of eastern Iowa reducing visibility to a half mile or less for several hours. Thundersnow was reported at several locations Wednesday night into Thursday morning. Conditions began to improve rapidly from west to east on Thursday afternoon as the storm system departed to the east.

Blizzard in JONES, IOWA
From 19-DEC-12 18:00:00 to 20-DEC-12 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters reported from 5 inches at Scotch Grove to 5.7 inches at Monticello.  The highest wind gust observed was 33 knots by the Monticello AWOS.

Blizzard in BUCHANAN, IOWA
From 19-DEC-12 17:00:00 to 20-DEC-12 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter 4 miles west of Stanley in Buchanan County reported 12.0 inches of snow.  The AWOS in Independence reported a peak gust of 46 knots during the storm.

Blizzard in DELAWARE, IOWA
From 19-DEC-12 17:00:00 to 20-DEC-12 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter in Manchester reported 7.9 inches of snow.

Blizzard in DUBUQUE, IOWA
From 19-DEC-12 18:00:00 to 20-DEC-12 18:30:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

An official observer at Dubuque Regional Airport reported 14.2 inches of snow. A trained spotter in Peosta reported 6.5 inches of snow. The peak wind speed during the event was 42 knots.

Blizzard in JOHNSON, IOWA
From 19-DEC-12 17:58:00 to 20-DEC-12 20:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotters in Johnson County reported between 2.5 inches in Iowa City and 4.9 inches in North Liberty. The ASOS in Iowa City recorded a peak wind gust of 43 knots.

Blizzard in LINN, IOWA
From 19-DEC-12 17:00:00 to 20-DEC-12 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters reported snowfall totals ranging from 5.0 inches 1 mile west of Marion to 8 inches at Coggon.

Blizzard in JACKSON, IOWA
From 19-DEC-12 18:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A COOP observer 4 west of Maquoketa measured 8.0 inches of snow.

Blizzard in IOWA, IOWA
From 19-DEC-12 18:00:00 to 20-DEC-12 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reports ranged from 4.3 inches at Williamsburg to 7.0 inches at Victor.

Blizzard in CEDAR, IOWA
From 19-DEC-12 18:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer in Lowden reported blizzard conditions with visibility below a quarter of a mile. The same observer also measured 8.0 inches of snow.

Blizzard in KEOKUK, IOWA
From 19-DEC-12 20:00:00 to 20-DEC-12 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Blizzard in SCOTT, IOWA
From 20-DEC-12 10:00:00 to 20-DEC-12 20:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Snowfall totals in Scott County ranged from 3.3 inches in Walcott to 5.3 inches at the National Weather Service in Davenport to 7.0 inches in Parkview. The peak wind gust measured by the Davenport ASOS was 45 knots.

Blizzard in LOUISA, IOWA
From 20-DEC-12 10:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Blizzard in DES MOINES, IOWA
From 20-DEC-12 10:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter near Burlington reported 3 inches of snow. The ASOS at Burlington reported a peak wind gust of 42 knots.

Blizzard in MUSCATINE, IOWA
From 20-DEC-12 06:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall amounts in Muscatine County were around 6 inches. The peak wind gust measured at the Muscatine AWOS was 45 knots.

Blizzard in LEE, IOWA
From 20-DEC-12 10:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter reported 3 inches of snow in Donnellson. The Keokuk AWOS reported a peak wind gust of 44 knots during the event.

Blizzard in JEFFERSON, IOWA
From 20-DEC-12 01:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Blizzard in WASHINGTON, IOWA
From 20-DEC-12 00:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported 2 inches of snow in Washington. The Washington AWOS reported a peak wind of 46 knots.

Blizzard in HENRY, IOWA
From 20-DEC-12 06:00:00 to 20-DEC-12 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Blizzard in CLINTON, IOWA
From 20-DEC-12 10:00:00 to 20-DEC-12 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall reports ranged from 4.5 inches at Camanche to 5.5 inches at DeWitt and Charlotte. The peak wind gust at the Clinton AWOS was 44 knots.

Blizzard in VAN BUREN, IOWA
From 20-DEC-12 10:00:00 to 20-DEC-12 18:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall reports ranged from  4.0 inches of snow near Cantril to 7.6 inches of snow near Keosauqua.

Blizzard in BENTON, IOWA
From 19-DEC-12 17:00:00 to 20-DEC-12 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall reports in Benton Country ranged from 6.2 inches at Atkins to 11 inches 1 mile southeast of Vinton. The peak wind gust measured at the Vinton AWOS was 37 knots.