Winter Storm Warning: Tracking Rain & Snow Across Eastern Iowa

Winter Storm Warning: A storm system approaching from the west will bring rain Thursday afternoon that mixes with and changes to snow Thursday evening, creating slick spots on roadways tonight into Friday morning and making the commute treacherous.

Winter Storm Warning: timing and immediate impacts

Cloudy skies and cooler temperatures will precede the changeover from rain to snow after sunset. The transition is expected Thursday evening as colder air moves in. That change will create slick spots on roads tonight into Friday morning, increasing the risk of hazardous driving conditions during evening and morning commutes.

Expected snowfall totals

The heaviest accumulation is forecast north of a line stretching from Waterloo to Prairie du Chien, where 2 to 4 inches of snow are possible. Areas south of that line are expected to see lighter amounts, ranging from a trace to 2 inches. The forecast notes that a few degrees of temperature difference could shift those totals, so final amounts remain sensitive to small changes in temperature.

Travel and weekend outlook

Drivers should prepare for slippery conditions tonight into Friday morning; road surfaces could be uneven with pockets of snow and residual wet spots that freeze. Friday is expected to be windy but drier as the system moves out, with conditions clearing afterward. Temperatures are projected to remain chilly through the weekend.

• Major impacts tonight: rain changing to snow, slick spots, treacherous commute.
• Snow totals: 2–4 inches north of the Waterloo–Prairie du Chien line; trace to 2 inches south.
• Friday: windier and drier, with lingering chilly temperatures into the weekend.

Analysis and forward look: If temperatures fall a few degrees earlier in the evening, the area seeing 2 to 4 inches could expand slightly; conversely, a warmer surface would reduce accumulations. With the heaviest snow focused north of the Waterloo–Prairie du Chien line, communities along and north of that corridor should be especially vigilant during the overnight hours. Motorists are advised to allow extra travel time and exercise caution on untreated or untreated-appearing surfaces tonight and Friday morning.