textproduct: Des Moines

KEY MESSAGES

- Light rain chances over western into north central Iowa lifting out of the state overnight. A few additional showers southwest into central Iowa on Tuesday.

- Additional, periodic rain and storm chances from midweek into early next week with dry intervals between these chances. Widespread shower and storm chances are forecast later Wednesday into Wednesday night and then again late Thursday night through at least Saturday.

- For Wednesday's storm chances, a few strong storms are possible and it cannot be completely ruled out a severe storm or two.

- Temperatures remain seasonal if not above normal through the next week.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 140 PM CDT Mon Oct 26 2026

The forecast over the next week can be summarized as featuring seasonal if not above normal temperatures paired with interval chances for showers and at times thunderstorms. For the next couple of days, there are a series of shortwave troughs moving through the northern and southern stream flow that will bring rain chances to various portions of the state. The first round of showers is ongoing this afternoon over northwest and far northern Iowa where the strongest low level thermodynamic forcing is located, which is on the northwestern periphery of a zone of mid-level ridging that is centered over the central Gulf Coast States. This forcing is ahead of a northern stream shortwave trough, which will lift northeastward into Minnesota by Tuesday morning bringing an end to the showers over Iowa. With more cloud cover and the showers that have occurred at times today over northern Iowa in our forecast area, this has resulted in lowering temperatures below the initial National Blend of Models (NBM) forecast.

While the showers will have ended over northern Iowa by sunrise Tuesday as the northern stream wave pulls away, a southern stream shortwave trough will be advancing towards southeastern Iowa. This may lead to a few showers, but coverage of any showers is expected to be more minimal over the state compared to what it is/was today. This is expected as forecast soundings and cross sections show a ribbon of saturation of great vertical depth from southwest into northeast Iowa with weak forcing within this layer/ribbon. While anywhere in this ribbon could see light rain, have focused low (~20%) chances over southwest into central Iowa for now where the relatively strongest lift is forecast. Outside of this light rain area, there is a good amount of dry air overtop the low level saturation so limited sunshine/good amount of cloud cover is expected elsewhere in the state. NBM once again looks too aggressive with warmth, especially over northern and western Iowa, and have adjusted highs down in these areas by 2 to 3 degrees with lesser to no change in our southeastern forecast area. A shower or two may remain possible Tuesday night, but the decreasing depth of saturation and the weak lift precludes any mention above 15% at this time.

Yet another shortwave trough - from the northern stream this time - will press eastward over the northern states and southern Canadian prairies on Wednesday with a surface cold front stretched through the northern into the central Plains. Ahead of this front, breezy winds from the south and warm conditions will prevail. This front will bring more widespread shower and thunderstorm chances later Wednesday into Wednesday night. Appreciable instability is forecast to pool along this boundary along with favorable low level kinematics and deep layer shear pointing to at least a few strong storms. This is hinted at in this morning's day 3 SPC outlook. A few isolated, elevated severe storms are possible, which is supported by the AI/ML severe probabilities; however, the weak lapse rates may negate this severe potential.

LONG TERM /THURSDAY THROUGH MONDAY/

Issued at 140 PM CDT Mon Oct 26 2026

Any storms are expected to have ended by sunrise Thursday morning as the front clears the forecast area stalling just south of Iowa. After a short dry period Thursday, this boundary will lift back northward over the state as low level theta-e advection ensues Thursday night into Friday ahead of the next southern stream shortwave. The shower and storm chances will be prolonged Friday into at least Saturday, though there are likely to be some breaks. Further, will need to monitor diurnal ranges as highs may be too high and lows too low in the cloudy and damp period. Even if temperatures were lowered now, they would still be seasonal as typical late October highs are in the upper 50s to around 60 degrees. With the southern stream wave lifting over Iowa on Sunday, this may bring some drier conditions back over the state late in the weekend. By early next week, a few deterministic models are more amplified or negatively tilted with a trough approaching the region; however, ensembles and AI guidance are generally lower amplitude and less wound up. The takeaway is that a trough of some variety and tilt will be moving through the region early next week and this should spur a continuation of more active weather/shower and storm chances Monday into Tuesday. Confidence in any details beyond this are low at this time.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 626 PM CDT Mon Oct 26 2026

IFR cigs currently over far northwest Iowa and lower cigs will be moving east/southeast over the next 24 hrs. Expect cigs to lower to MVFR at KFOD/KMCW Tuesday morning. Expect VFR conditions to prevail at KDSM/KALO/KOTM though an isolated shower may occur at KDSM late tonight. Easterly wind will turn more southerly during the period.

DMX WATCHES/WARNINGS/ADVISORIES

None.