textproduct: Des Moines

KEY MESSAGES

- Milder on Tuesday, especially in snow free areas.

- Wintry precipitation placement challenges later Wednesday into early Thursday. Accumulating snowfall is possible in a band over some portion of Iowa, but there is uncertainty in where this will set up.

- Existing and possible new snow cover will impact Friday temperature forecast. Temperatures do look to trend lower this weekend.

DISCUSSION

Issued at 156 PM CST Mon Feb 23 2026

The weather over Iowa today is tranquil with surface high pressure passing through the region with a Nor'easter raging near the 40/70 benchmark and a ridge over the western US. There are a few mid and high level clouds over the state with a more expansive area just to the west over Nebraska. At the moment, however, a clear sky that allows great viewing of the swath of snow over the state from southwest to northeast. This snow area poses great challenges to the temperatures forecast, especially late this week, that will be detailed below. As the surface high pressure slides to the east this afternoon, our low level flow will become from the south and later southwest before a cold front pushes through the state later on Tuesday. Warm air advection will precede the front along with plenty of mid and high level clouds. Temperatures will push well into the 40s in the snow free areas and perhaps low 50s along the Missouri border. For areas that have snow on the ground, temperatures will be lower than the initial National Blend of Models (NBM) and have blended in 25th percentile NBM to account for the snow. The front that will move through the state will be associated with a shortwave trough and surface low tracking along the US/Canada border into the Great Lakes. Most of the precipitation is forecast to fall north of Iowa where there will be stronger forcing closer to the low. However, cross sections show saturation aloft reaching far northern Iowa, which is trying to work its way down to the surface Tuesday afternoon. The saturation is rather fleeting and the degree of dry air in the sub-cloud layer results in a continued dry forecast.

The shortwave passing on Tuesday will aid in developing a broad, low amplitude trough over the Great Lakes and Ohio Valley while at the same time sheared out energy topping the ridge will flow into this developing trough. The track of this energy, which right now looks to be through Nebraska/Kansas into the Ozarks, should bring accumulating snow and rain into some portion of the state as moisture overruns the now stalled out front well south of Iowa. The placement of this precipitation varies greatly over the state with model trends not lending confidence to one solution over another. Timing wise, precipitation looks to arrive later Wednesday over central Iowa exiting by sunrise Thursday. Beyond Thursday, temperatures on Friday are too high from the initial NBM in the areas that have or will have snow. This is partially a result of models being too warm earlier in the week, which results in more melting of the snow pack than what will likely be reality and thus allows for more warming vs energy devoted to melting snowpack. In addition, there will be new snow that falls Wednesday/Wednesday night with placement issues already discussed that will temper the warmth. As another cold front surges through the region late this week or early this weekend, temperatures will trend toward seasonal levels. While moisture may be limited this weekend, there is a signal for snow with phased thermodynamic and kinematic forcing in the area.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1113 AM CST Mon Feb 23 2026

VFR ceilings and visibility will prevail throughout the entire forecast period. Winds are currently from the northwest over eastern Iowa but will become from the south/southwest this evening. Low level wind shear is possible overnight into tomorrow with a frontal passage, but mentions of low level shear were removed from FOD, MCW, and ALO due to shear being minimal at best. Mention for shear was kept at DSM and OTM due to a stronger signal, but impacts are expected to be marginal.

DMX WATCHES/WARNINGS/ADVISORIES

None.