textproduct: Des Moines

KEY MESSAGES

- Areas of patchy fog possible this morning. - A cooler, drier airmass settles over Iowa today, bringing comfortable conditions and slightly below average temperatures.

- Rain and thunderstorm chances return to the state Late Sunday.

SHORT TERM /THROUGH TONIGHT/

Issued at 125 AM CDT Sat Aug 22 2026

The cold front has cleared central Iowa, with a dry and comfortable airmass building in behind it. Quiet conditions established overnight will persist through Saturday afternoon. Patchy Fog remains possible early Saturday morning, though confidence in widespread coverage is limited due to dry air advecting in from the north. The highest probability for fog will reside along low river valleys and portions of southern Iowa, where boundary layer moisture and higher dew points linger.

Surface high pressure expanding across Northern Plains will maintain comfortable conditions today, keeping dew points in the 50s to lower 60s. High temperatures will be noticeably cooler than Friday, dipping slightly below seasonal averages in a few locations; making for a great day to be outdoors. Quiet weather continues Saturday night, though cloud cover will gradually increase across western Iowa as a weak shortwave passes over the High Plains. Measurable precipitation is unlikely with this feature, but better chances for showers and thunderstorms arrive Sunday night.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 230 PM CDT Fri Aug 21 2026

Iowa remains seated between a ridge centered over the Four Corners region and a trough over the Great Lakes. If either of these systems shift, that will change how far east or west moisture gets back into the area by Sunday night, which is when the next shortwave looks to move through, potentially bringing more precipitation chances into Sunday morning. At the moment, however, deterministic guidance is still struggling with the timing of this system. With this comes some degree of disagreement with placement, all of which will be better assessed in the coming days. This upper level pattern looks to remain rather stagnant, with the potential for additional shortwaves to move through the region next week.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1039 PM CDT Fri Aug 21 2026

Skies are clear for the most part across the state except for some lingering smoke aloft. This may continue into tomorrow but is not expected to be impactful. Some patchy fog development remains possible tonight, particularly at KOTM, but given the extra breeze behind the front and dry air advection, seems unlikely at this point. Cumulus may develop at KDSM/KOTM terminals tomorrow but will likely stay VFR.

DMX WATCHES/WARNINGS/ADVISORIES

None.