textproduct: Des Moines

KEY MESSAGES

- Local river valley fog tonight.

- Breezy to gusty winds on Tuesday.

- Scattered showers and thunderstorms possible Thursday night

SHORT TERM /THROUGH TONIGHT/

Issued at 234 PM CDT Mon Oct 5 2026

Widespread mostly sunny skies were across Iowa gain this afternoon. High pressure was beginning to move to the east today as while low pressure was entering the Lee side of the Rockies to the west. The trough will continue to move east tonight with strong theta-e advection developing across Iowa later tonight into Tuesday morning. Despite the theta-e advection, no saturation is anticipated as the air mass over the state is very dry, therefore, no precipitation is expected. A few areas with river valley fog is possible again tonight but the over all coverage should be less than this morning with a more sustained wind expected. The increased pressure gradient and diurnal mixing will lead to gusty southwest winds. High temperatures will be in the 70s to near 80 in a few locations. Side note for today.

LONG TERM /TUESDAY THROUGH MONDAY/

Issued at 234 PM CDT Mon Oct 5 2026

Little change in the overall pattern through Friday as the upper level flow remains a modified westerlies leading to mild and mostly dry conditions. The caveat being Thursday night and Friday morning as a few showers and storms could develop by another round of moisture return with surface low pressure moving to the east and return flow commences. Upper low pressure will descend into the Pacific Northwest this weekend leading to a gradual amplification of southwest flow into Iowa. This will lead to warmer temperatures this weekend, with more widespread 80s possible. A bit beyond the 7 day forecast and perhaps the next widespread weather potential for Iowa arrives mid next week as the upper low shifts east into the Plains and may bring thunderstorms back to Iowa.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 632 PM CDT Mon Oct 5 2026

Surface high pressure will allow for categorical VFR TAFs through the 00Z TAF window. Winds are forecast to diminish over the next couple of hours but as a disturbance moves toward the region, a low level jet will develop. This could allow for a few hours of LLWS at KFOD and KMCW before turbulent mixing negates LLWS. However, confidence on the window of LLWS before mixing is low; therefore, left LLWS out of the TAF. Winds are forecast to increase across all sites Tuesday morning. Lastly, river valley fog is possible overnight and impacts to terminals are possible.

DMX WATCHES/WARNINGS/ADVISORIES

None.