textproduct: Des Moines

KEY MESSAGES

- Breezy and dry conditions through the rest of today with gusts near 25mph and highs in the 80s.

- Shower and storm chances return Friday night into Saturday morning. Additional storm chances will continue through the weekend and next week.

- A pattern change will lead to warming temperatures and higher humidity. Heat indices will be in the 90s.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 1213 PM CDT Wed Aug 26 2026

A boundary has passed through Iowa overnight and is currently pushing east out of the state. Behind it, drier air has entered the area as evident on water vapor imagery. This leads to dewpoints in the low 60s. Tonight, a surface high moves into the area leading to much lighter winds. This high pressure and light winds may lead to some patchy fog but dewpoints will be too low for widespread fog. While low, patchy fog potential looks best across far southern Iowa.

Dry air remains around the state tomorrow leading to more pleasant conditions with highs in the low to mid 80s. Tomorrow night the high will move out of the area before our next shortwave arrives. The day Friday will still remain dry, although surface flow from the south will lead to warmer air being advected into the state with highs being a few degrees warmer. Despite this southerly flow at the surface, moisture transport is cut off by the influence of the surface high still departing to the east.

Northwesterly flow remains in the midlevels and moisture transport looks much better there. The shortwave will enter the region and enhance the Low Level Jet (LLJ), providing forcing for elevated showers and storms, mainly in northern and western Iowa where more moisture is available. Unsurprisingly, point soundings show there is a fair bit of dry air across northern Iowa that would need to be saturated for rain to reach the ground. If storms do form and move across northern Iowa, this layer of dry air could lead to sporadic gusty winds. If the aforementioned surface high moves farther south than modeled, this could help with better low level moisture and would lead to higher chances for showers and storms. Sounding profiles do look much better across northeastern Iowa as this goes on through Saturday morning as a better plume of low level moisture catches up to this system.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 1213 PM CDT Wed Aug 26 2026

Behind the showers and storms Saturday morning, breezy conditions are expected due to a tight pressure gradient and strong flow at the low levels. High pressure is still pancaking the Four Corners region leading to a broad upper level ridge and keeping Iowa in northwest flow through Saturday. Over the weekend the high is expected to weaken as the ridge is broken down by a potent trough that enters the Pacific Northwest. This will end up leading to a pattern change with warmer temperatures and more humid conditions through the end of the weekend and into next week. As the pattern changes, additional storm chances are possible with any shortwave that rides eastward across the broad upper-level ridge.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 625 PM CDT Wed Aug 26 2026

VFR conditions ongoing and expected to continue through the TAF period. Gusty winds and diurnal cumulus that developed today should continue to dissipate here around sunset with lighter winds out of the north to northwest, but may become variable at times, and mainly clear skies overnight. Still monitoring the potential for patchy fog overnight with light winds and clear skies but dry air keeps confidence in development low. Expecting more diurnal cumulus to develop on Thursday.

DMX WATCHES/WARNINGS/ADVISORIES

None.