textproduct: Des Moines

KEY MESSAGES

- Intermittent shower chances through Friday. Isolated non- severe thunderstorms may occur.

- Frost/Freeze potential limited tonight due to cloud cover potential. Greater chance for Frost/Freeze Friday night into Saturday morning.

SHORT TERM /THROUGH SATURDAY/

Issued at 228 AM CDT Thu Apr 30 2026

Upper level low pressure is settling into the central Great Lakes region and will remain in that vicinity through Friday. Two distinct PV anomalies/short wave clusters will drop through the resultant northerly flow. The first will arrive today while the second system arriving late tonight into Friday. This will result in chances for showers and perhaps a few non-severe thunderstorms. The thunderstorm chances will be mainly across southern Iowa on Friday as static stability becomes low with low theta-e difference between the tropopause and the boundary layer along with some modest CAPE developing from surface instability. The other potential impact of the second system is increasing clouds tonight from north to south and the impact on frost/freeze potential. Will be holding off on any frost/freeze headlines because expected there will be a broad area of cloud cover and will limit low temperature potential tonight and the clouds will impact frost formation. There will still be pockets of frost where holes in the cloud cover occurs but pinpointing those areas while that system is still over northern Alberta is difficult. Friday night and Saturday morning will have a greater potential for frost/freeze with subsidence behind the departing system and surface high pressure arriving. There is a scenario where low temperatures reach the mid to upper 20s over northern Iowa as dew points in the 20s advect in and the potential for radiational cooling is increasing.

LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/

Issued at 228 AM CDT Thu Apr 30 2026

Saturday will remain cool but pleasant with light winds followed by warm advection Saturday night into Sunday as the northerly upper level flow relaxes and becomes more northwesterly. Upper level low pressure develops near Hudson Bay late Sunday and will result in long wave troughing through the Upper Midwest by mid next week. This will bring a cold front through the state Monday night and Tuesday. This will bring the next chance for precipitation along with another round of cooler weather. Upper level ridging will occur over the western CONUS during this time. That ridging will move east late next week and will bring a return to warmer weather.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 624 AM CDT Thu Apr 30 2026

Showers will move across the area this morning with minor vsby restrictions at times. A boundary moving south through the state will bring northerly winds to the area. The wind will be breezy at times this afternoon. The wind will become light and variable at times tonight. Increasing clouds and perhaps a few more shower are possible by late tonight but confidence is low enough to exclude any restrictions at this time.

DMX WATCHES/WARNINGS/ADVISORIES

None.