textproduct: Des Moines

KEY MESSAGES

- A few isolated storms skim northern Iowa overnight tonight.

- Additional thunderstorms in southwest Iowa Friday evening and overnight.

- Mostly dry and sunny through the weekend!

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 222 PM CDT Thu Aug 20 2026

High pressure has allowed for tranquil conditions across the area today with a few diurnally driven clouds in southern Iowa. Farther north a shortwave is moving across the upper midwest, resulting in a few thunderstorms across Minnesota. A few high clouds have moved across northern Iowa associated with this wave. The cold front trails across South Dakota and into Nebraska this afternoon and will move east, pushing across Iowa overnight and on Friday. Better forcing will be across Minnesota near the surface low and scattered thunderstorms are expected there, extending along the front. A few of these may skim northern Iowa overnight. While an isolated stronger storm is possible, these will largely be confined north and west of the area where forcing and instability are better phased.

Much of Friday will then be dry with northwest flow helping to bring high level smoke from fires across the Pacific northwest. Another embedded wave riding along the western US ridge will slide across Nebraska and southwest Iowa Friday evening. This will bring another chance for scattered thunderstorms. Forcing is again modest and focused largely west of the area, but with 1500+ J/kg MLCAPE and 40 kts of shear, a few stronger to severe thunderstorms are possible in the evening.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 222 PM CDT Thu Aug 20 2026

Any lingering storms in far southern Iowa should clear out early Saturday morning with dry conditions through the weekend. Another embedded shortwave will move across Iowa late Sunday evening into Monday, slowing from model solutions 24 hours ago. The upcoming work week looks to remain active with embedded shortwaves continuing to ride along the western US ridge with northwest flow across Iowa. A more robust system looks to move across the area on Tuesday and will be the next opportunity for more organized convection. At this time range differences remain with the GFS favoring a southerly track over the Euro northerly track.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 638 PM CDT Thu Aug 20 2026

VFR conditions ongoing and largely expected to continue through the TAF period. Clouds and lower ceilings are expected to skim KMCW this evening as showers and occasional storms pass nearby. These ceilings are expected to remain VFR and showers largely expected outside of the 5 mile radius around KMCW. There is a chance for a shower/storm impacting KMCW, but confidence is below 30% needed for a prob 30 group, but will monitor trends closely. A few other showers may develop in portions of central Iowa into Friday morning but overall chances are below 20% and coverage will be isolated at best, so no precip mentions included.

DMX WATCHES/WARNINGS/ADVISORIES

None.