A potent low pressure system tracked from eastern Oklahoma and Missouri into northern Illinois and the Great Lakes region, from December 28th to the early morning hours of the 29th. An unseasonably warm and moist airmass interacted with the system to produce heavy mixed precipitation across eastern Iowa. Thundersnow was reported in some areas, as well as heavy snow, sleet accumulations up to 2-4 inches, and a glaze ice amounts over a quarter inch. The ice and strong winds gusting to 50 mph resulted in widespread downed trees and powerlines, and power outages. The hardest hit areas, with glaze ice amounts of 1/4-1/2 inch, were located in southeastern Iowa. The highest amounts of combined snow and sleet, in the 5-7 inch range, occurred west and north of a line from Brighton, IA in Washington County, to Cedar Rapids, Anamosa, and Dubuque Iowa.

Winter Storm in WASHINGTON, IOWA
From 28-DEC-15 03:00:00 to 28-DEC-15 21:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer in Brighton reported freezing rain that changed over to a mix of sleet and snow. They estimated 0.20 to 0.30 inches of freezing rain accumulation and snow and sleet accumulation of 5.0 inches.

Winter Storm in JOHNSON, IOWA
From 28-DEC-15 04:00:00 to 28-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

COOP Observer and trained spotters reported a snow and sleet accumulation between 3.0 inches in Iowa City and North Liberty to 3.5 inches 1 west of Elmira.

Blizzard in CEDAR, IOWA
From 28-DEC-15 04:00:00 to 29-DEC-15 00:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP Observer in Lowden reported 5.0 inches of sleet and snow.

Winter Storm in SCOTT, IOWA
From 28-DEC-15 04:00:00 to 29-DEC-15 00:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Trained spotters reports ranged from 2.0 inches near Walcott to 3.8 inches 1 mile northwest of Davenport. The official NWS observation at the Davenport Municipal Airport was 3.6 inches. A trained spotter reported a quarter of an inch of ice accumulation in Walcott before precipitation changed over to sleet.

Winter Storm in CLINTON, IOWA
From 28-DEC-15 05:00:00 to 29-DEC-15 02:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP Observer in Clinton reported 2.5 inches of sleet.

Winter Storm in LINN, IOWA
From 28-DEC-15 05:00:00 to 28-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reports ranged from 3.3 inches near Beltram to 5.4 inches at Springville to  6.7 inches at Palo.

Winter Storm in LEE, IOWA
From 28-DEC-15 00:30:00 to 28-DEC-15 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A mix of sleet and freezing rain fell through the event. There was a light glaze on paved surfaces. There were also reports of 300 to 400 customers without power in Fort Madison.

Winter Storm in LOUISA, IOWA
From 28-DEC-15 05:00:00 to 28-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Unknown

Freezing rain fell during the morning and transitioned to sleet later in the day.

Heavy Snow in BENTON, IOWA
From 28-DEC-15 05:00:00 to 28-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snowfall reports in Benton County ranged from 6.0 inches by a COOP Observer in Vinton and a trained spotter in Belle Plaine to 7.2 inches on the southeast side of Atkins.

Winter Storm in VAN BUREN, IOWA
From 28-DEC-15 01:00:00 to 28-DEC-15 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A COOP Observer in Keosauqua reported 2.5 inches of sleet. Trained spotter reports in neighboring counties were about a quarter of an inch of ice before the changeover to sleet.

Winter Storm in DES MOINES, IOWA
From 28-DEC-15 02:00:00 to 28-DEC-15 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters reported between 0.20 and 0.25 inches of ice accumulation on the morning of December 28th. Ice was accumulating on trees. Several branches and small trees were down in the county. The largest branches were 4 to 5 inches in diameter. In addition to the freezing rain, a trained spotter reported an inch of sleet in Burlington.

Winter Storm in JEFFERSON, IOWA
From 28-DEC-15 02:00:00 to 28-DEC-15 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer in Fairfield reported 2.3 inches of sleet. There were no reports of ice accumulations.

Heavy Snow in JONES, IOWA
From 28-DEC-15 05:00:00 to 29-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A combination of snow and sleet fell across Jones County which ranged from 4.8 inches at Olin to 6.0 inches 2 miles south southwest of Anamosa, Monitcello, and Center Junction.

Heavy Snow in DELAWARE, IOWA
From 28-DEC-15 06:00:00 to 29-DEC-15 02:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported 6.0 inches of snow mile south of Edgewood in Delaware County.

Winter Storm in JACKSON, IOWA
From 28-DEC-15 06:00:00 to 29-DEC-15 03:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP Observer near Maquoketa reported 6.0 inches of snow and sleet.

Heavy Snow in DUBUQUE, IOWA
From 28-DEC-15 06:00:00 to 29-DEC-15 04:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

The official NWS observation taken at the Dubuque Regional Airport was 6.8 inches of sleet and snow.

Winter Storm in KEOKUK, IOWA
From 28-DEC-15 03:00:00 to 28-DEC-15 21:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer in Sigourney reported 4.0 inches of sleet and snow.

Winter Storm in MUSCATINE, IOWA
From 28-DEC-15 03:00:00 to 28-DEC-15 21:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotters reported 1.5 to 3.0 inches of sleet across Muscatine County.

Winter Storm in IOWA, IOWA
From 28-DEC-15 04:00:00 to 28-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reports of snow ranged from 4.3 inches on the northwest side of Parnell to 7.2 inches in Atkins which is in Benton County.

Heavy Snow in BUCHANAN, IOWA
From 28-DEC-15 06:00:00 to 28-DEC-15 22:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trained spotter reports in Buchanan County reported between 6 inches 1 mile east of Independence to 7.5 inches at Hazelton.

Winter Storm in HENRY, IOWA
From 28-DEC-15 02:00:00 to 28-DEC-15 19:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The COOP observer in Mount Pleasant reported 2.5 inches of sleet.