Flurries, Gusty Winds, and Snow Chances Ahead

KEY MESSAGES:

Today: Light snow and rain south of Interstate 80, with temperatures hovering around freezing. Some slick spots on roads are possible due to slush, but accumulation on grassy surfaces will be minimal.

Thursday: Snow is expected, primarily in central and southern Iowa, with potential for advisory-level snowfall. Travel impacts are possible during the day.

Colder Weather: Winter conditions will take hold starting Thursday, with temperatures dropping into the teens by early next week. Snowfall amounts and winter weather impacts are still being monitored.

Short-Term Forecast (Today through Wednesday)

Confidence: Medium

A 500mb low pressure system has continued to deepen overnight, bringing precipitation to Iowa, primarily focused along and south of Interstate 80. As the system moves east, rain and snow will continue to shift southeast, with temperatures hovering around freezing through the morning in the southeast. Although the melting layer is shallow, temperatures are warm enough to limit accumulation on grassy surfaces. However, roadways could still be slick due to slush, and localized higher amounts of snow are possible along a deformation axis forming over eastern Iowa.

Throughout the afternoon, gusty winds up to around 30 mph will accompany light flurries. Cold air advection (CAA) will steepen lapse rates in the planetary boundary layer (PBL), contributing to the flurries, but due to shallow saturation and subsidence, snowfall will remain light. The gusts will decrease quickly as cloudiness dwindles, and we can expect clearing skies in the western parts of the state. Temperatures will remain near freezing for much of the day, with lows expected to drop into the teens in the northern and western areas overnight due to radiational cooling.

Thursday and Beyond: Snow and Winter Conditions

Confidence: Medium to High

The next significant weather system arrives Thursday, bringing snow primarily to central and southern Iowa. This time, temperatures will be cold enough to ensure snow as the primary precipitation type. Lift is expected to maximize in the mid-morning to midday hours, with around 50% of ensemble members predicting at least 1 inch of snow for the day. There are factors that could lead to higher snowfall amounts, especially due to the magnitude of forcing and its overlap with the dendritic growth zone (DGZ). Forecasts suggest the potential for advisory-level snowfall in a narrow band, and this will need to be closely monitored. Travel impacts are likely, especially during the daytime on Thursday.

After Thursday’s snow event, colder winter conditions will settle in. An energetic trough from the Pacific Northwest will dive southeastward, bringing colder temperatures to the region. Although deterministic models are trending southward with snowfall forecasts, it’s important to monitor the forecast closely as this system develops. Iowa may experience some winter weather impacts, though the exact details are still uncertain.

Looking Ahead

As we move into early next week, an upper-level closed low will descend upon the Great Lakes region, ushering in even colder air from an Arctic high in Canada. Highs are expected to drop into the teens early next week, with cold temperatures likely sticking around through at least the rest of the workweek. Snowfall from the weekend system will be more confined to the southern parts of the state, but overall winter conditions are set to take hold, with the potential for snow and other winter weather impacts to be monitored closely.

Stay informed as the weather continues to evolve, especially as we approach Thursday’s snow event and the colder temperatures expected next week. Be prepared for slick roads, gusty winds, and winter weather impacts as the season settles in.