textproduct: Des Moines

KEY MESSAGES

- Scattered thunderstorms through early this evening. A few severe storms remain possible.

- Mostly dry tonight into Saturday.

- Additional thunderstorm chances late Saturday night into Sunday.

- Active weather will persist through much of next week.

SHORT TERM /THROUGH SATURDAY/

Issued at 243 PM CDT Fri Aug 7 2026

Thunderstorms are ongoing over north central Iowa in advance of a boundary that is moving in from the northwest. MLCAPE values of 2000- 3000 J/kg along with mid-level lapse rates at 8-8.5 C/km have led to strong initial updrafts with 65 dBZ over 20 kft occurring. The primary storm initialization is on a pre-frontal trough that has extended into northern Iowa from west to east. Expect much of the activity this afternoon to remain associated with the current storm cluster with the potential for some additional development back west/southwest along the pre-frontal trough. These storms will maintain a damaging wind and large hail threat through the remainder of the afternoon as the entire system settles south/southeast. These storms should exit south into Missouri by early this evening.

The remainder of tonight into much of Saturday is expected to be dry. Much drier dew points will settle into the state behind the boundary with dew point values falling into the low 50s north to low to mid 60s south. Deep layer drying will also be occurring which will further support the dry forecast.

LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/

Issued at 243 PM CDT Fri Aug 7 2026

Return flow begins Saturday night as high pressure moves to the east of the state. Strong theta- e advection and an increasing low level jet of 40-45 kts will lead to increasing instability and thunderstorm chances.

Upper high pressure over Hudson Bay combined with upper high pressure over the Four Corners region, will lead to progressive westerly flow over much of the northern CONUS with periodic embedded short waves passing across Iowa. This flow will also keep a surface boundary in the Midwest area and resulting in several chances for thunderstorms before Canadian high pressure arrives early next week. PWAT values of 1.50-2.00" will be common during active storm periods that could lead to an aggregate heavy rain threat through the week. Temperatures will be seasonal and mainly in the 80s through midweek the gradual cooling as the Canadian high pressure approaches for the end of next week.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 644 PM CDT Fri Aug 7 2026

Lingering areas of MVFR ceilings are expected to remain over the next few hours near and behind the passing boundary that is over central Iowa. Storm potential largely remains near/at KOTM before 03z, before dry conditions are expected to return for all sites. Patchy fog is possible mainly at the eastern terminals where residual moisture from the rain, plus light winds and clearing skies are expected, with less confidence further west where drier conditions are noted. Northwest winds are expected to shift southeasterly across the forecast area after 12-15z Saturday, with VFR conditions expected through the remainder of the current TAF period.

DMX WATCHES/WARNINGS/ADVISORIES

None.