textproduct: Des Moines

KEY MESSAGES

- The forecast is dry through the coming work week with slowly warming temperatures.

- A bit breezy through Sunday, though not nearly as much as it was on Saturday.

- Rain chances and more changeable weather conditions may return next weekend, but forecast details are still in flux at this range.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 128 PM CDT Sat Oct 17 2026

We got off to a cool start this morning, with much of our service area experiencing the first freeze of the season. A few stations such as the Des Moines airport and Lamoni remained just above freezing around 34-35, but most other stations fell to 32 or below, and in most of our northern and western counties the temperature fell below 30 degrees.

The surface ridge that was draped across much of Iowa last night is sliding southeastward today, and will reside roughly along or just north of the Ohio River valley by Sunday morning. Meanwhile, a broad low pressure trough is forming along the lee of the Rockies, and the pressure gradient between the trough and the ridge will be located more across our area from this afternoon through Sunday afternoon. This will result in fresh south to southwest breezes during that time. Temperatures will remain a bit below seasonal normals this afternoon, combining with the breezes to keep things a bit chilly outside despite the resplendent sunshine. The breeze will then help temperatures stay up tonight, with lows around sunrise Sunday more in the lower 40s or so throughout our forecast area. However, any more sheltered spots where winds to light overnight may cool into the mid/upper 30s. On Sunday temperatures will rebound due to airmass modification, with highs generally in the mid 60s making for a glorious autumn day.

From Sunday night through Monday night the surface pattern will loosen up, resulting in lighter winds. A broad high pressure area will persist to our east, roughly over the Great Lakes region, with light southeasterly breezes in our area entraining dry air out of that ridge. Dry, clear conditions with light winds will support a continued warming trend during the day, and good cooling conditions overnight but again with a slow modification trend continuing. NBM temperatures in this regime, from Sunday through Monday night, are a bit too low during the day and a bit too high during the night as it appears to be overdone with its surface humidity/dewpoints. Have thus continued the trend of bumping up daytime temps and bumping down nighttime temps. The result is Monday afternoon highs approaching 70 degrees in our southeastern counties, with Sunday night and Monday night lows generally in the upper 30s to mid 40s. Additional freezes are not anticipated in the near future.

LONG TERM /TUESDAY THROUGH FRIDAY/

Issued at 128 PM CDT Sat Oct 17 2026

By Tuesday morning, a broad 500 MB high pressure ridge will be located over most of the central and eastern U.S. However, a weak shortwave will be moving off the Rockies and over the High Plains. This feature will pass slowly near Iowa on Tuesday into Wednesday, bringing some mid/high level clouds across the region during that time. A few model solutions even attempt to spit out light rainfall, however, forecast soundings indicate substantial dry air in the lower/near-surface levels with flow out of the Great Lakes ridge, which should preclude any meaningful chances of precipitation. Meanwhile, despite some increase in cloud cover, airmass modification should allow for continuation of a slow warming trend with temperatures peaking in the lower 70s or so on Wednesday afternoon.

From late Wednesday into Friday a more pronounced 500 MB ridge will build over the central U.S., including Iowa, supporting continued dry weather and slow warming. Highs in the 70s are forecast both Thursday and Friday. Eventually, by the end of the week, a deep 500 MB trough will move into the western U.S. Rockies and bring a return of more changeable weather and some rain chances by next weekend. Any details of timing/location of rain chances and other sensible weather fields are still in flux at this range, but will steadily come into better focus as this week progresses.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1228 PM CDT Sat Oct 17 2026

VFR conditions are expected for the foreseeable future, with no precipitation, obscurations, or low clouds anticipated. SSW breezes will gust to around 20 KT at times today and again on Sunday, but will drop off overnight tonight. As this occurs, winds just off the deck will pick up a bit overnight, resulting in LLWS concerns. This will be minimized toward the southeast and maximized toward the northwest, so have introduced LLWS groups at FOD and MCW after 05Z but not at the other terminals.

DMX WATCHES/WARNINGS/ADVISORIES

None.