textproduct: Des Moines

KEY MESSAGES

- Breezy winds out of the northwest today with gusts up to 25 mph. Highs in the 80s through Friday.

- Shower/storm chances return late Friday night into Saturday morning with additional chances later in the weekend and into early next week.

- Warming temperatures into the weekend with heat indices in the 90s on Sunday.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 213 AM CDT Wed Aug 26 2026

Meager flow with a subtle reflection of a boundary was evident across central Iowa overnight. Calm winds were reported over most of southern Iowa where dew points remained in the 70s. This has allowed for the development of fog, especially in the Nish Valley. Looking behind the front, dew points were dropping into the 50s. The front should sink to the I-80 corridor by morning, the dry air advection eating into the fog north of it. Areas of fog under 2 miles will be possible in southern Iowa for the morning commute. It may potentially be dense (1/4 mi or less) close to the Missouri border and in the Nish Valley where the winds are lightest. The need for a Dense Fog Valley will be assessed through the morning. Fog will burn off and lift to low clouds, these eventually being pushed south with the front through the morning. We'll be left with mostly sunny skies and highs in the low 80s. Northwest winds will increase in the afternoon with gusts up to 25mph possible north of Highway 20.

Temperatures will be similar on Thursday, but with high pressure dropping the winds.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 231 PM CDT Tue Aug 25 2026

The upper ridge starts to move eastward on Friday as the eastern trough deamplifies flattening out the flow a bit into the weekend. The surface high pressure also moves off to the east during the daytime Friday. Several rounds of shortwave energy pass through the flow with moisture returning late Friday night into Saturday morning on the nose of the low level jet (overnight Friday night). This will bring the return of shower and storm chances (20-40%) especially west/north. Although there will be dry periods, active weather continues the later part of the weekend into early next week as well with several additional chances for showers/storms. Temperatures begin an upward climb again Saturday into Sunday with heat indices in the 90s on Sunday at this time range.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1234 AM CDT Wed Aug 26 2026

Light fog has developed this evening but so far has not expanded or worsened significantly. Some expansion overnight is likely, but is expected to remain southwest of the terminals, toward northern Missouri and Nebraska. The terminal most likely to be impacted is OTM, where a TEMPO for MVFR visibility has been introduced. That site remains AMD NOT SKED, but amendments could be needed at DSM or ALO overnight if fog expands more than current expectations. Other than fog potential, TAFs are VFR on Wednesday, with some modest wind gusts to around 20kts in the afternoon.

DMX WATCHES/WARNINGS/ADVISORIES

None.