textproduct: Des Moines

KEY MESSAGES

- Accumulating snow late this afternoon into Friday morning. A narrow band of heavier snow amounts will set up over central Iowa with amounts decreasing quickly outside of this band. A Winter Weather Advisory is in effect over much of central Iowa.

- Increasing winds and falling temperatures tonight into Friday with cooler, more seasonal, temperatures Friday into the weekend.

UPDATE

Issued at 328 AM CST Thu Feb 19 2026

Very challenging snow forecast for today. Still looking at the potential for some light precipitation to develop this morning in the warm air advection wing of the incoming system though dry air remains a limiting factor. If anything were to reach the ground, it would be most likely as light rain or a couple sprinkles given the location and timing, though largely expecting the dry air to win out this morning. Profiles start to saturate this afternoon with precipitation chances increasing from midday into early afternoon from western into portions of central Iowa as the deformation zone arrives. This precipitation may initially begin as rain or a rain/snow mix before changing to snow.

The biggest change to the going forecast is the location of the heaviest band of snow. Model guidance is in pretty good agreement that there will be a band of heavier snow amounts somewhere across central Iowa. The most likely is a band of 2-5" with an even narrower corridor of 6+". The OOZ guidance between CAMs and global models was all on board with a more southerly track extending from west central to northeast Iowa, including portions of the I-80 and US-30 corridors. As can happen with narrow band snow systems, some of the latest 6Z guidance has started a small trend back north. It is still looking unlikely the snow will occur over far northern Iowa so the Winter Weather Advisory from yesterday afternoon was shifted southward last evening and only a small change eastward early this morning. The footprint of the advisory may still be too large and adjustments may still be needed. There remains considerably uncertainty with exactly where the greatest impacts will be felt but light to moderate amounts are generally expected within the advisory area, with a narrow area of heavier amounts, but snow totals may vary greatly from one side of a county to another. As an example, a county in northern Iowa could see near to less than 1" in the far north side of the county and 2-3" or more on the southern side of the county. This makes headline decisions difficult when full counties have to be included. Additionally, the warm ground temperatures and any rain early make snow accumulation amounts tricky but may be counteracted by the rate of snow. Snow rates near or exceed 1" per hour at times leading to poor visibility and quickly accumulating snow on roadways resulting in challenging and slick road conditions. The snow type will certainly be wet. There is also good agreement of increasing winds out of the north with gusts to 20-30 mph. With the wet nature, blowing snow itself will be less of a concern, but visibility may be impacted as snow falls. The main takeaways are hazardous winter weather conditions will be felt across portions of central Iowa today as snow accumulates which may impact the evening commute. Only other change was cooled temperatures considerably for today with the quickly increasing cloud cover and the warm sector largely held to the south of Iowa.

DISCUSSION

Issued at 301 PM CST Wed Feb 18 2026

On the heels of the departing low pressure northeast into Wisconsin by early Thursday will be the arrival of another dynamic surface low pressure system into the western Central Plains. Iowa is expected to remain relatively dry through the morning to early afternoon hours, though CAMS have been indicating some potential for very light rain with the lift of the warm air advection wing through the state, though soundings indicate that dry air will quite substantial yet, which would likely keep any precipitation from reaching the ground. The focus with this system primarily rests on the arrival of the deformation zone associated with this low pressure system, which has trended later in terms of arrival, with a band of snow setting up into Iowa by late Thursday afternoon to evening and passing east/northeastward into Friday morning. Models guidance continues to show differences on the overall tracking of this band of snow, with CAM guidance mostly keeping this band over portions of north to north-central Iowa, while experimental AI guidance and the deterministic NAM are placing this band closer to the I-80 corridor. Given overall model trends over the past few days, as well as considerations of where the colder air allowing for snowfall through the column, the current thinking is for accumulating snow to generally reside more into north-central to northern Iowa. In terms of the mesoscale details, deep lift through a generally well saturated sounding, including the DGZ per northern Iowa sounding guidance suggests the increasing potential for a period of 1-2 inch snow rates for a short period Thursday evening, which given these rates would allow for this snow to stick rather quickly even as surface temperatures may still be slightly above freezing. Given this potential, have issued a Winter Weather Advisory over north to north-central Iowa in coordination with neighboring offices to outline this potential. Amounts below an inch are possible further south Thursday evening into Friday. The main important takeaways are that a band of efficient snowfall is expected to move into Iowa by late Thursday afternoon to evening, though the exact location remains uncertain given the differences mentioned above, and will likely still see at least some slight shift in the amounts, with trends being monitored very closely. Outside of the precipitation, a tightening pressure gradient in response to the deepening low pressure will lead to breezy conditions across Iowa as well Thursday. However, with the expected temperatures closer to freezing, this snow is expected to be more on the wet side, which will keep the blowing snow potential very minimal. The primary impacts of concern will be hazardous travel due to lowered visibility and slick roads.

As any lingering precipitation decreases through Friday morning, cooler air will continue to spread across Iowa through the day from increasing northwest flow. Highs are expected to be in the upper 20s to 30s. Into the weekend, cooler and generally dry conditions look to continue, with the Saturday system of question in earlier forecast packages now trending drier as the weak shortwave from the south looks to struggle with the large area of cool and dry air from the incoming Canadian surface high pressure. Therefore, have leaned on a mainly dry weekend forecast.

AVIATION /06Z TAFS THROUGH 06Z FRIDAY/

Issued at 1102 PM CST Wed Feb 18 2026

The two main impacts over the next 24 hours are the shifting winds and arriving winter storm. Gusty winds will continue to calm through the overnight before increasing again to 20-25 kts after 18z. Westerly winds will shift to northerly by midnight, and shift further to northeasterly by 12z. As the storm arrives midday tomorrow, the forecast becomes increasing complex and uncertain. A band of rain and snow will set up somewhere in central Iowa, reducing visibilities and bringing with it lowered ceilings, and likely MVFR to IFR conditions beyond 21z. The exact track of the heaviest precipitation is still uncertain, though at this time recent trends have shown snow impacting KDSM and KALO, but could impact KMCW, KFOD, and KOTM as well. Current TAFs largely reflect MVFR conditions tomorrow evening, but the heaviest snow bands could induce IFR conditions and future TAFs will be updated as necessary.

DMX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from 3 PM this afternoon to 6 AM CST Friday for IAZ023-024-033>035-044>047-057>059-070>072-081-082. Winter Weather Advisory from 6 PM this evening to 6 AM CST Friday for IAZ025>028-036>039-048>050-060>062-073-074.