textproduct: Des Moines

KEY MESSAGES

- Rain with a few thunderstorms are possible Sunday morning. A few stronger storms could produce small hail up to quarter sized.

- Strong cold front passes across Iowa northwest to southeast through the day on Sunday. Rain transitions to a wintry mix with a light glaze of ice possible, mainly in northern Iowa. Then a full transition to snow that will last through Sunday night and taper off Monday morning. By Monday morning temperatures will be near 0 with wind chills in the -10s to -20s.

- Strong winds will gust 55-65+ mph, resulting in significant blowing and drifting of snow. White-out conditions are expected at times. Travel will become very dangerous.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 248 PM CDT Sat Mar 14 2026

A dynamic storm system is setting up to bring a variety of impacts to Iowa beginning overnight tonight. A large low pressure system will deepen as it passes across Iowa on Sunday. Initially in the warm air advection wing, showers will pass across Iowa early Sunday morning. A sharp cold front will then pass across the state from northwest to southeast, bringing a transition to a wintry mix, then all snow. Snow will continue through Sunday evening, tapering off overnight. By Monday morning temperatures will fall to near zero. This strong low will cause wind gusts of 55-65+ mph, resulting in significant blowing and drifting of snow. White-out conditions are possible at times and travel will become very dangerous. Each facet of the storm will be discussed in detail below.

Convection...

On Saturday afternoon the surface low was draped across northern Kansas through central Missouri. As the low shifts east this will lift across Iowa and into Minnesota and Wisconsin. Those areas are expected to see a heavy snow band set up with this trending north of Iowa compared to data earlier this week. While Iowa will largely miss out on snow from the warm air advection wing, a plume of 500 - 1000+ J/kg of MUCAPE will extend into Iowa along with 0-6 km wind shear of 40-50+ kts. Showers and thunderstorms are expected to develop in this warm sector early Sunday morning, as early as 3-4 am in the west and exiting east by 8-10 am. Expect to see mainly elevated hail with this convection on Sunday morning.

Temperatures and Precipitation Type...

A sharp cold front will pass across Iowa from northwest to southeast through the day on Sunday. Temperatures will drop sharply, starting the day in the 40s and 50s and ending in the single digits to near zero. Combined with strong winds (discussed below), wind chills by Monday morning will be very cold in the -20s north to -10s south. This could be particularly dangerous for anyone that becomes stranded while traveling or if the strong winds result in power outages.

Rain will transition to a wintry mix before switching over to snow by Sunday afternoon. A light glaze of ice is possible with that wintry mix. Snow may initially be wet and heavy, but as the column quickly cools will become lighter and fluffy. Soundings indicate a sharp cold front beneath the elevated warm nose, and this will help reduce the time period of heavy wet snow making it to the surface. A slushy layer may develop at snow onset as snow falls on previously wet ground from earlier liquid rain. As temperatures fall sharply, this will freeze quickly, likely creating a layer of ice beneath the snow that falls later in the day. These layers are notoriously difficult to remove. Snow will quickly become light and highly blowable, creating a dangerous situation with the expected strong winds. Snow tapers off early Monday morning.

Snow Amounts...

Snow to liquid ratios (SLRs) will be low initially due to the wintry mix. Despite deep isothermal layers through the dendritic growth zone (DGZ) and strong omega with a very cold sounding profile, SLRs will remain limited later in the event by the very strong winds. With gusts of 55-65+ mph anticipated, expect fragmentation of dendrites to reduce ratios. While the NBM produced 18-20:1 ratios, these were pulled back closer to 12-14:1.

While the heaviest snow band associated with the warm air advection wing is expected to set up north of the Iowa-Minnesota border, the deformation zone will still pivot across Iowa Sunday afternoon and evening. There is deep moisture advection into the area and snow amounts of 3-7+ inches remain possible across Iowa. Frontogenesis is strong through 700mb with the 700 mb front lagging the surface front, allowing for a prolonged period of lift to enhance snow totals. Ingredients are there for higher end totals of 6-10" to be realized in a few locations if the deformation zone sets up in the right place.

High Wind...

The back side of this low brings strong cold air advection, strong subsidence, and a tight pressure gradient - all the ingredients needed for a high wind event. Soundings indicate 60-70+ kts at 850mb with deep mixing to and beyond that layer. At the surface, an extremely tight 70-80 ubar/km pressure gradient is setting up across Iowa. All to say, very strong winds of 55-65+ mph are expected across all of Iowa on Sunday, tapering off on Monday morning. This will result in significant blowing and drifting of snow. White- out conditions are expected at times with travel becoming extremely dangerous. This wind could also result in power outages. And lastly, with the strong shear and available instability along the front, the snow squall parameter highlights Iowa into Missouri. While the Blizzard warning covers this hazard, it is important to note that, especially in southern Iowa, visibility could be highly variable through the event.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 242 PM CDT Sat Mar 14 2026

A shortwave will move across the midwest on Tuesday, grazing northern Iowa. This will bring another opportunity for light snow accumulation to northern Iowa. Thereafter, western US ridging shifts into the central US with high pressure keeping the area quiet and strong warm air advection into the area. Temperatures Wednesday and Thursday could be slightly overdone depending on how much snow needs to be melted, but by the end of the week and next weekend, temperatures are expected to warm through the 60s and make a run at low 70s.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 650 PM CDT Sat Mar 14 2026

Although VFR conditions are mainly in place to start the period, aviation conditions will degrade considerably through the period. Initially, MVFR conditions creep into northwest Iowa and then northern Iowa this evening. Rain showers begin north early overnight, transitioning to a wintry mix, and then becoming all snow Sunday morning. A similar transition will happen in central to southern Iowa, but is delayed until closer to Sunday midday (early afternoon for KOTM). Some thunderstorms will be possible early Sunday morning but confidence in impacts at at TAF site too low for inclusion. A light glaze of ice remains possible in mainly northern Iowa with the wintry mix. As the precipitation changes, visibilities will degrade to MVFR, becoming IFR to LIFR/VLIFR as the snow arrives with significant blowing/drifting of snow expected by around 18Z. Ceilings will similarly degrade with IFR or lower expected through much of the area through Sunday afternoon. Winds are the other main hazard with winds out of the southeast tonight gusting to 20-30 knots. The winds will switch to be out of the northwest as a strong cold front passes through Sunday morning with gusts of 40-50+ knots common Sunday afternoon and evening causing blizzard conditions with the falling snow.

DMX WATCHES/WARNINGS/ADVISORIES

Blizzard Warning from 7 AM Sunday to 7 AM CDT Monday for IAZ004>007-015>017-023>028-033>039. High Wind Warning from 1 PM Sunday to 4 AM CDT Monday for IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075- 081>086-092>097. Blizzard Warning from 1 PM Sunday to 7 AM CDT Monday for IAZ044>050-057>062-070>075-081>086-092>097.