Snow and Below-Average Temperatures Expected Through the Weekend

KEY MESSAGES

• Thursday Snow (90-100% confidence): Snow is expected, especially across central and southern Iowa, with 1-3 inches possible and locally higher amounts. The northern extent of the snow remains uncertain.

• Below Average Temperatures: Cold air will settle in through the weekend, with temperatures staying below average for at least the next week.

• Weekend System (Sunday): A large system is expected to impact the region on Sunday, with the highest snowfall amounts likely south of Iowa, but this may change. Keep monitoring the forecast.

Short-Term Forecast (Today through Thursday)

Confidence: High

Iowa is seeing colder air move in as northwest winds bring dry, cool conditions. Wind gusts of up to 30 mph will continue through the morning hours, especially in the northern and eastern parts of the state. Despite breaks in the clouds, temperatures will remain cold, with highs only in the 20s and 30s.

Tonight, cloud cover will increase as a clipper system moves in from the Pacific Northwest. The system is expected to bring snow, with amounts ranging from 1 to 3 inches across central Iowa. While there’s a high degree of confidence in the general snow forecast, localized snowfall amounts may be higher, particularly along the I-80 corridor. Several factors, including vertical motion, instability in the dendritic growth zone (DGZ), and potential for higher snow ratios, could lead to increased snowfall in certain areas. Some models are showing potential for snow amounts of 3-4 inches in localized areas.

Extended Forecast (Friday through Sunday)

Confidence: Medium

As snow from Thursday night clears out, the colder temperatures will become more pronounced, with highs for the weekend expected to drop into the teens. The biggest concern beyond Thursday is the large system expected on Sunday. Ensemble guidance shows that the highest snowfall amounts may be focused on areas south of Iowa, with parts of northern Missouri and eastern Iowa seeing the heaviest snow. Around 40% of model members suggest more than 4 inches of snow for far southern Iowa, but there is still significant uncertainty regarding the system's exact track and intensity.

Currently, snowfall amounts are forecast to be moderate, but the potential for higher snow totals remains as snow ratios could exceed 10:1. Confidence in exact snowfall amounts remains low (around 20%), and the forecast will need to be monitored as we get closer to the event.

Looking Ahead

A major shift in weather patterns is expected to take place next week, with an upper-level low settling over the Great Lakes region, bringing an extended period of below-average temperatures. Highs will remain in the teens, with lows approaching zero, making for a prolonged cold snap. Snow from the weekend system could add to the cold, but the focus will be on frigid temperatures that could last through the workweek.