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 SUNDAY/

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 /SUNDAY 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 /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1054 PM CDT Fri Aug 7 2026

While KOTM will see remaining cloud cover given lingering shower and storm activity near and ahead of the boundary into southeast Iowa, VFR conditions are expected to return across all terminals. Patchy fog remains possible mainly at the eastern terminals where recent rainfall has occurred, paired with light winds and clearing skies. Any fog should lift after sunrise, with skies otherwise hazy from lingering wildfire smoke through the day. Winds will shift from northwest to southeast into mid- late morning. Monitoring for the potential for shower and storm activity late in the period and beyond, but confidence is too low at this time to include directly at any terminals.

DMX WATCHES/WARNINGS/ADVISORIES

None.