textproduct: Des Moines

KEY MESSAGES

- A line of severe storms will move across Iowa late afternoon and evening. A few non-severe showers and storms possible ahead of the main line. The line of storms will have wind as the primary hazard, though tornadoes and hail are possible.

- Cooler Friday through the weekend. Multiple rounds of showers and thunderstorms possible this weekend and early next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 207 PM CDT Thu Apr 23 2026

A few spotty showers have developed in the moist plume extending into Iowa, though have been fairly sort lived with little mechanism to sustain development. Meanwhile, convection has fired along and just ahead of the cold front pushing across Nebraska and into western Iowa. This will push across Iowa this evening, reaching the I-35 corridor around 7-9pm and pushing east after midnight. There was some concern that prefrontal convection would prevent more robust development with the main line of storms. While this has not yet materialized, the widespread stratus has put a bit of a damper on instability. There is little DCAPE out there and with moist soundings through the low levels, that may prevent better cold pool development except in northern Iowa where there is drier air in place. This would impact wind potential with the line as it blows through. A pool of 2500+ J/kg SBCAPE is in place across western to central Iowa with the Creston sounding showing 1900+ ECAPE as some may not be realized due to entrainment. Shear is largely parallel to the boundary. This could limit some of the tornado threat unless a bowing section can take better advantage of line normal shear. Tornado threat would be highest with initial convection that is more likely to be surface based, along with the low LCLs around 500m. Hail concerns will also be greatest with initial discrete convection when lapse rates are steeper around 7-8 C/km. As the line grows upscale with column moistening and pushes east later this evening threats will start to diminish.

LONG TERM /FRIDAY THROUGH THURSDAY/

Issued at 207 PM CDT Thu Apr 23 2026

Relatively cooler conditions settle in Friday through the weekend and much of the upcoming week. While cooler that recent days, average highs this tie of year are in the mid 60s, so temperatures will be closer to what is "typical" for this time of year. The pattern remains active This weekend and next week as several embedded shortwave eject east from a longwave trough parked across Alberta and Saskatchewan. The first is rather weak and may skim the area on Saturday. Then a more robust wave lifts out of Missouri towards the area on Sunday. This will interact with the main longwave trough finally digging east Sunday into Monday. As this interacts with the system lifting out of Missouri thunderstorms are expected into Iowa. Placement of the warm sector will impact severe threats into Iowa and will be better determined in the next few days.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 623 PM CDT Thu Apr 23 2026

Main aviation concern in the short term will focus on progression of line of strong to severe thunderstorms through central Iowa.

Thunderstorms with heavy rain will impact all terminals with low-end MVFR to IFR conditions likely. Cannot rule out brief LIFR, but will monitor trends for this threat. Have maintained greatest impacts at DSM/FOD/MCW as intensity should be highest at these sites before slight decreases east of I-35. Can't rule out brief 40+ knot gusts as leading edge of storms move in but will pinpoint timing better before inserting mention at DSM with later amendments.

Tonight, skies should clear quickly once TSRA depart. Will maintain some lower coverage of low/mid clouds for the early morning Friday before sunny to mostly sunny skies prevail across the area for the bulk of the daytime Friday. Winds may increase early in the morning, potentially around 20-25 knots our of the northwest, with a gradual decrease towards the end of the period.

DMX WATCHES/WARNINGS/ADVISORIES

None.