textproduct: Des Moines

KEY MESSAGES

- Light snow possible across northern Iowa tonight into early Saturday. Snow amounts generally under an inch.

- Winter system moves through late Saturday night through Sunday, with strong winds on Sunday leading to potential blizzard conditions. Highest snowfall accumulations expected over northern and north central Iowa. A brief period of freezing rain possible as rain transitions to snow Sunday morning.

- A few thunderstorms possible central and south on Sunday morning. Hail would be the main concern with any storms.

- Wind gusts of 45 to 55 mph are possible during the day on Sunday.

SHORT TERM /THROUGH MONDAY/

Issued at 301 PM CDT Fri Mar 13 2026

The strong winds from last night and this morning gusted up to 69 mph, but have lessened considerably today. While much less than last night, breezy northwesterly winds do still continue today, generally around 15 to 20 mph with gusts up to 35 mph. As pressure gradients wane this afternoon and evening, we'll also see winds generally decrease through tonight, becoming light by early tomorrow morning. A brief period of high pressure will move through overnight before surface low pressure builds from the west ahead of a prominent winter system slated to impact the midwest this weekend.

Our first sign of arrival for this system will actually be tonight into early Saturday, as a wing of theta-e advection lifts northward into the state. Moisture availability aloft will be plentiful with this wing, but lacking at the surface, meaning top-down saturation will need to take place before snow reaches the ground. This has been trending drier with recent guidance, but have maintained at least light snow accumulations (under an inch) along the Iowa/Minnesota border.

The main synoptic wave will approach the area through the day on Saturday, streaming warmer air and a healthy plume of moisture up into the state into the evening and overnight hours. This will result in a broad swath of heavy snowfall mainly over Minnesota and Wisconsin, and potentially far northern Iowa Saturday night into early Sunday. That said, the recent trend in guidance has been farther north with this initial band overnight Saturday into Sunday, with most of guidance keeping snow out of Iowa through 12z on Sunday. To account for this drier trend Saturday night, have pushed the start time for the Winter Storm Watch back to 06z on Sunday, which may still be too early if the band doesn't wiggle back southward.

While the initial band of snow is trending north, these solutions also result in more instability being pulled up into Iowa early Sunday morning. Dry mid-level air may inhibit storm development, but a few rumbles of thunder can't be ruled out as the low passes overhead Sunday morning, especially along the warm front. Hail would be the main concern with any storms, and severity looks low given instability values generally under 500 J/kg. That said, the Colorado State University machine learning severe probabilities are keying on some hail probabilities over Iowa and the storm prediction center does have an outlook for general thunder and a marginal risk for severe weather in far southeastern Iowa early Sunday, so will want to at least keep the potential for storms in mind.

Given the guidance today, what looks like the main story of this system will be the TROWAL development and wrap around precipitation occurring behind the surface low passage during the day on Sunday, in addition to very strong winds developing behind the low. The GFS and NAM are most bullish on this wrap around snowfall, showing anywhere from 3 to 6 inches on average, with even higher amounts along northern Iowa pushing 10"+ by Monday morning. These two solutions also show the surface low deepening overhead, while other solutions have it deepen farther east instead, which results in heavier snowfall amounts over eastern Iowa and lower amounts in central Iowa, generally in the 0 to 2" range. Therefore, confidence is low in the amount of snow that will fall on Sunday but confidence is high for strong winds developing with gusts of 45 to 55 mph possible, similar to this morning. Any snow that does occur on Sunday with these winds will lead to blizzard-like conditions, at least while the snow is falling. Therefore, while there is a lower likelihood of the initial heavy snow band impacting northern Iowa Saturday night into Sunday, and uncertainty still exists with total snow amounts during the day on Sunday, the winter storm watch will remain in place for much of central into northern Iowa for the potential blizzard conditions on Sunday. Even if we don't get snow, winds will be approaching high wind criteria over much of the state as well, so wind headlines will eventually be needed. Strong winds will continue into Monday morning. Depending on the amount of snow that falls on Sunday, blowing snow could persist into early Monday morning, impacting the Monday morning commute as well.

Finally, as if there wasn't enough to consider already with this system, we are also monitoring potential for some freezing rain and/or ice pellets as the cold air initially arrives on Sunday morning. This likely wouldn't be long lived, as liquid precipitation transitions over to a snowfall with the colder temperatures, but a few hours of freezing rain may still lead to a light glazing of ice before snow falls on top of it. This threat looks most likely over northern Iowa early Sunday morning, but could develop in portions of central Iowa as well.

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/

Issued at 301 PM CDT Fri Mar 13 2026

Winds will remain breezy but steadily diminish through Monday afternoon and evening. Temperatures will be much cooler on Monday with highs only reaching the teens to low 20s. These cooler temperatures then continue into into Tuesday with one more weaker system bringing snow potential Tuesday night into Wednesday. Beyond Wednesday, ridging then builds in from the west, warming temperatures through the end of next week. This should help to melt any snow on the ground, with the return of highs in the 50s and 60s possible by next weekend.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 644 PM CDT Fri Mar 13 2026

VFR conditions ongoing and largely expected to continue through the TAF period. Although Prob30 for light snow remains at KFOD/KMCW, the chances continue to decrease with very dry air limiting precipitation from reaching the ground. May still need to remove but didn't quite have the confidence to pull mentions completely. Any lingering gusty winds will continue to diminish this evening, shifting to be out of the east by early Saturday before increasing to over 12 knots, gusts to 20-25 knots, and becoming out of the southeast by the afternoon.

DMX WATCHES/WARNINGS/ADVISORIES

Winter Storm Watch from late Saturday night through Monday morning for IAZ004>007-015>017. Winter Storm Watch from Sunday morning through Monday morning for IAZ023>028-033>039-044>050-057>062.