textproduct: Des Moines

KEY MESSAGES

- Cold conditions to start the week, but milder on Tuesday, especially in the snow free areas.

- A 12 to 18 hour window of wintry precipitation is forecast Wednesday into early Thursday. Accumulating snowfall is possible in northern portions of the state.

- Big temperature spread/low confidence in temperatures late this week into next weekend.

DISCUSSION

Issued at 149 PM CST Sun Feb 22 2026

GOES-East upper level water vapor imagery shows a shortwave trough scooting southeastward over Iowa early this afternoon. Much of the expansive stratus area is to the east of this shortwave track over eastern Minnesota, Wisconsin, and northeastern Iowa. However, there are stratus streaks (best viewed - perhaps oddly - in the Blowing Snow RGB) accompanying this wave over western Minnesota and a small area of the eastern Dakotas. These streaks along with the expectation that the stratus will sink southward this evening will bring cloud cover back towards an Estherville to Des Moines to Centerville line. Forecast soundings do try to briefly saturate just above the dendritic growth zone to produce flurries this evening over our northeastern forecast area, but the depth of saturation is quite shallow so have opted to keep forecast dry. The saturation is fleeting as a zone of high pressure pushes into the forecast area drying out the column resulting in clouds dissipating. With the high also allowing for winds to diminish toward sunrise Monday, particularly over western Iowa, this will foster a cold morning with temperatures falling to around zero degrees and wind chills ranging from 5 degrees below zero to 15 degrees below zero.

While highs on Monday will still be in the upper teens and 20s, mid- level heights will be on the rise. This combined with a southerly to westerly warm air advection flow on Tuesday will offer milder conditions, especially in the snow free parts of the state. In these areas, the initial National Blend of Models (NBM) is well into the 40s and is close to the 50th percentile and only a few degrees lower than the 75th percentile for highs Tuesday. MOS guidance is actually similar if not cooler than NBM so will hold temperatures at the initial guidance for now in the snow free areas. For highs within the swath of snow cover, this area will be on the cooler side of guidance and the NBM continues to show the snow footprint well, but temperatures are still a bit too warm. Interestingly, the MOS guidance in these areas is at or a few degrees higher than the NBM with modeled snowfall matching well with satellite imagery. In addition, a shortwave trough and surface low pressure passing north of Iowa will send a cold front through the state later on Tuesday, resulting in breezier winds from the west and northwest. The precipitation with this system looks to stay mostly north and northeast of central Iowa where the stronger QG convergence will be placed. This system will shunt the Pacific moisture southward and while low level theta-e advection will begin ahead of the next shortwave trough arriving Wednesday into Thursday, the moisture return will be limited. The precipitation axis is bouncing around in its placement in the deterministic, ensemble, and AI models, but most of these agree that some portion of central Iowa is still on track for a 12 to 18 hour period of wintry weather and likely accumulating snowfall to some portion of northern Iowa as well. Beyond Thursday, temperatures Friday into next weekend show great spread between the 25th and 75th percentile - some pushing near 35 degrees on Saturday. Thus, confidence in the deterministic NBM forecast temperatures is low.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1024 PM CST Sun Feb 22 2026

Low stratus continues to dissipate as dry air moves in over Iowa, which has led to an increasing likelihood for clouds to decrease sooner than expected, as all terminals should return to VFR conditions around 06z if not shortly afterward. Outside of high clouds streaming in later in the day, mostly clear skies are largely anticipated, as any lower clouds generally remain east of the state. Winds will continue to decrease, turning light and variable as high pressure settles overhead, then turning southerly into the evening.

DMX WATCHES/WARNINGS/ADVISORIES

None.