As with many snowfall events, a sizable low pressure system slid south of Iowa roughly from central Kansas into central and southeast Missouri.  As a result, Iowa was left solidly within the precipitation shield as warm air was brought up over the warm front and wrapped back into the low pressure system.  Temperatures ahead of the system were in the upper 30s to low 40s in most cases.  As temperatures cooled from infiltrating cold air rain turned over to snow, heavy at times. Snowfall generally began after 10 pm on the 23rd and lasted through much of the morning on the 24th before tapering off from northwest to southeast.  The heaviest snowfall amounts were seen over northern Iowa from about Estherville to Mason City and down to Waterloo, where as much as 12 to 18 inches of snow fell.  Areas further south saw a slower transition to snow and fewer bouts of heavy snowfall, resulting in amounts around 4 to 8 inches on the southern edges of the winter storm warning. However a period of freezing rain did lead to some ice accumulations in areas along Highway 30 prior to the period of snow.

Winter Storm in EMMET, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in PALO ALTO, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in KOSSUTH, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WINNEBAGO, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 11:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in HANCOCK, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 11:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WORTH, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in CERRO GORDO, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in WRIGHT, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in FRANKLIN, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BUTLER, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BREMER, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in HARDIN, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 15:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in GRUNDY, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BLACK HAWK, IOWA
From 23-MAR-18 22:00:00 to 24-MAR-18 16:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in POCAHONTAS, IOWA
From 24-MAR-18 00:00:00 to 24-MAR-18 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in HUMBOLDT, IOWA
From 23-MAR-18 23:00:00 to 24-MAR-18 13:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in HAMILTON, IOWA
From 24-MAR-18 00:00:00 to 24-MAR-18 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in CALHOUN, IOWA
From 24-MAR-18 01:00:00 to 24-MAR-18 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in GREENE, IOWA
From 24-MAR-18 01:00:00 to 24-MAR-18 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in POWESHIEK, IOWA
From 24-MAR-18 03:00:00 to 24-MAR-18 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reports of icing from freezing rain around one to two tenths of an inch combined with additional snowfall.

Winter Storm in WEBSTER, IOWA
From 24-MAR-18 00:00:00 to 24-MAR-18 13:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in STORY, IOWA
From 24-MAR-18 00:00:00 to 24-MAR-18 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reports of icing from freezing rain around two tenths of an inch to possibly as much as one quarter of an inch combined with snowfall amounts up to 4.5 inches.

Winter Storm in MARSHALL, IOWA
From 24-MAR-18 00:00:00 to 24-MAR-18 14:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reports of icing from freezing rain around two tenths of an inch combined with snowfall amounts up to 3 inches.

Winter Storm in TAMA, IOWA
From 24-MAR-18 00:00:00 to 24-MAR-18 17:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Reports of icing from freezing rain around one to two tenths of an inch combined with snowfall amounts up to 3 inches.