textproduct: Des Moines

KEY MESSAGES

- Cold again today but lighter winds for much of the day. Warmer on Tuesday, especially in the snow free areas.

- Challenging precipitation forecast for Wednesday night into Thursday. Potential this system trends south.

- Warmer Friday but temper expectations where the snow remains.

DISCUSSION

Issued at 402 AM CST Mon Feb 23 2026

A broad surface high pressure ridge bisects the CONUS early this morning from northwest Minnesota to along the western Iowa border to eastern Texas. Temperatures under the ridge over west central and northwest Iowa have fallen near to slightly below zero. Temperatures are warmer over eastern Iowa where northwest winds remain breezy and some stratus has been in place. The ridge of high pressure will move slowly east across Iowa today and will keep the seasonally cold conditions across the state. That cold air will remain even further enhanced by the snow that is across a large part of the forecast area. The wind will be much lighter today compared to Sunday therefore, it will not be a repeat of yesterday's shallow blowing snow that melted on roadways then froze, leading to very slick conditions and accidents. The departing high pressure along with low pressure moving across North Dakota and northern Minnesota will result in return flow and strong warm/theta-e advection into Iowa. A short wave moving across Minnesota and Wisconsin into Tuesday will also transition the upper flow more westerly which will bring the Pacific moisture stream across Iowa. This will bring mid to high level cloudiness to Iowa and will have an impact on high temperatures along with the frequently mentioned snow cover. Temperatures certainly will be warmer that the past several days but may not have been aggressive enough tamping them down due to the aforementioned obstacles. The system passing to the northwest may bring a quick passing of light rain. At this time, have the area precipitation free but it will be close with cross sections and soundings showing a brief window for saturation to be attempted near Mason City Tuesday afternoon but there is a fair amount of low level dry air to overcome.

Wednesday will be cooler as a boundary will pass through the state following the Tuesday system. Trying to find a reason why the Wednesday night/Thursday system won't continue to trend southward compared to model guidance. There is nothing in the flow blocking it from digging south with general troughing developing over the central CONUS and the upper high pressure system just west of the California Baja shifts slightly west, promoting even more troughing. Jet streak still in the western side of the approaching short wave energy as it moves into the region, would further promote digging south. Both the deterministic EC and GFS are at least now showing the strongest upper level energy now much further south into Kansas then Oklahoma. The NAM seems to be is playing catch up along with NBM guidance. Precipitation chances and amounts into Iowa may hinge on the amount of moisture lifting north and over topping of the sfc boundary, which there is some hint at S/SW flow yet at 850 mb and a descent Pacific mid-level stream. Not planning any changes at this time and will keep precipitation chances as is as there could be a quick passing of rain/snow before the southern system strengthens. NBM high temperatures on Friday seem unrealistic at this point, where there is current snow cover. Melting will be limited prior to then and there remains a chance to add to it Wednesday night/Thursday. Even the NBM 10th percentile looks too warm for the snow region. In contrast, the NBM 75th may be too cool in the snow free areas. Stay tuned. There is a lot to monitor this week with forecast challenges throughout.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 528 AM CST Mon Feb 23 2026

Stratus is eroding over eastern Iowa but may still have a brief period of BKN035 at KOTM early in the period. Otherwise diminishing northwest wind this morning that will turn southerly this afternoon with the passing of high pressure. Low level wind shear is possible late tonight with low level wind turning just off the surface. Mostly cloud free today with mid to high level clouds increasing overnight.

DMX WATCHES/WARNINGS/ADVISORIES

None.