textproduct: Des Moines

KEY MESSAGES

- Moderate to heavy snow continues this afternoon, tapering off this evening across Iowa.

- Winds increase this evening and into Sunday morning, gusting 35+ mph. Blowing snow will reduce visibility and impact travel into Sunday.

- Colder Sunday into next week with highs in the teens to around 20 degrees. Lows in the single digits on either side of zero.

- Additional light snow Monday brings 1-2" to southern Iowa.

DISCUSSION

Issued at 216 PM CST Sat Nov 29 2025

The surface low is centered across northwest Missouri this afternoon with the northwestern side deformation zone stretching across Iowa. A band of heavy snow with high snow rates and visibility under 1/4 mile is currently set up across the Des Moines metro and east towards Grinnell. This has resulted in a number of accidents on the interstate already this afternoon. Light to moderate snow continues to fall across much of the rest of the state. The edge of precipitation has reached western portions of Iowa. Heaviest snow is ongoing and expected to last another couple hours, tapering off from west to east through this late afternoon and evening. Totals have been highest along the Highway 20 corridor so far today with widespread reports of 8-12+ inches. North and south of this corridor amounts ranging from 3-8 inches have been common. Expect another 2-4 inches of additional snow through the rest of this event.

As snow tapers off today northwest winds will increase with subsidence and strong cold air advection behind the system as the pressure gradient remains enhanced. Soundings indicate 25-35+ kts through the boundary layer overnight, tapering off Sunday morning. Despite falling snow ending, the layer of fresh powder for today will still be easily blowable, reducing visibility and blowing back onto previously cleared roads. Winds diminish midday Sunday as the low pushes further east, and clouds clear out. Lighter winds and sunshine should help with snow removal efforts on Sunday. Even so, much colder air filters in behind this system with highs on Sunday in the teens to near 20 degrees on Sunday with the wind making it feel more like 0 degrees. Overnight lows will fall to the single digits and below zero but the wind will die off and should not result in much of a wind chill.

On Monday an upper level wave dropping across the Rockies will undergo lee cyclogenesis and eject across the central plains. The low is set to track across Missouri with the northern deformation zone passing over southern Iowa. GFS soundings across southern to central Iowa show a deep isothermal layer within the dendritic growth zone for several hours on Monday. And while omega is modest during this period, the deep DGZ should allow for larger dendrite growth and enhance snow ratios. Areas south of I-80 may see an additional 1-2" Monday. A few subtle waves pass across the area this week, but with little available moisture the forecast is dry. The most notable impact of these waves will be periods of colder air pulled across Iowa.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 541 PM CST Sat Nov 29 2025

Snow will taper over the next 5 hours, but MVFR and locally IFR vsbys remain possible through the night due to BLSN. Gusts over 30kts are also possible overnight as northwest winds increase. Winds will ease through the morning and so will the BLSN, in tandem. IFR stratus will lift to MVFR, but will be stubborn to clear by 18z. Left a FEW/SCT MVFR mention and will assess stratus behavior ahead of the 06z issuance.

DMX WATCHES/WARNINGS/ADVISORIES

Winter Storm Warning until 6 AM CST Sunday for IAZ004>007- 015>017-023>028-033>039-044>050-057>062-070>075-081>086- 093>097. Winter Weather Advisory until 6 AM CST Sunday for IAZ092.