textproduct: Des Moines

KEY MESSAGES

- Another round of showers and isolated thunderstorms today from mid-morning into this evening. The threat for severe weather is reduced today.

- Additional rounds of thunderstorms are likely through much of next week. A daily risk of severe weather remains but details and timing will need to be fine tuned.

- Warmer and humid conditions for much of this week with highs in the 70s and 80s.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 433 AM CDT Sun Apr 12 2026

Well, we had some early morning excitement as a cluster of storms developed around 230am in far north- central Iowa, one of which became severe and produced at least half dollar sized hail across Winnebago County. Those storms have now moved off to the north and east.

Otherwise, similar thinking over the next few days. A large and deep upper level closed low is moving onshore along the PacNW resulting in broad southwesterly flow across the middle sections of the CONUS. Southerly low level flow continues to pump a warmer and more humid airmass into Iowa, with sfc Td values this morning in the 50s north to lower 60s south.

After an early morning lull in the precipitation, a subtle upper shortwave is expected to eject newd across the Corn Belt today. This will result in another push of low level moisture/thetaE across the region resulting in an uptick in showers and thunderstorms especially after 14-15z (9-10am). The latest guidance has continued to back off on the threat for severe weather today as plentiful cloud cover and weak mid level lapse rates should limit instability, with MUCAPE of 1000 J/kg or less. As such, the SPC has removed the Marginal Risk (Level 1) of severe weather today, which makes good sense. The highest chances /70-90%/ of showers and isolated storms today will be across SE sections of the CWA, generally along and south of a line from Grinnell, to Pella, to Lamoni. More scattered activity will occur north of this line. It will be breezy to windy today with south winds of 15 to 30 mph. High temps will rebound nicely with highs in the 70s south /more rainfall/ to around 80 in the northwest where more sun is possible.

Tonight, models are depicting mostly dry conditions. However, there is some evidence of the nocturnal low level jet re- emerging over the Midwest, so we'll need to keep a close eye on this.

Monday still looks interesting, and challenging. A more apparent sfc low will reform across NE/SD/MN, with a warm front extending eastward. As noted previously, a seasonally strong elevated mixed layer /EML/ will advect in from the west on Monday afternoon, with model soundings depicting a strong capping inversion very likely hindering convective initiation over much of the the warm sector, including Iowa. In fact, just about all of the CAM solutions show no convection over IA through 00Z Tue. It appears the most likely zone of CI and severe weather will be in the vicinity of the warm front, which at this point is forecast over southern, or perhaps even central MN! Due to remaining uncertainty over these mesoscale details, the SPC decided to keep the Slight Risk (Level 2 of 5) over portions of northern Iowa. Should a storm be able to form, the thermodynamic and kinematic environment would be supportive of severe weather. We've seen these setups often in the past, and in most instances the cap wins out, at least until after dark when the LLJ may again provide the impetus for storm development. Bottom line, keep up with the forecast.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 433 AM CDT Sun Apr 12 2026

Very little change to the thinking on Tuesday and beyond. The broad SW upper flow regime will remain in place with a series of impulses/shortwaves moving through the mean flow. The location of associated sfc low development and frontal position will play a key role in convective development, and the attendant risk for severe weather. In these patterns, the daily updates are required because the convective evolution on the "current day" will strongly influence subsequent days. Please refer to the SPC Outlooks for more details.

We are confident that it will feel spring, and perhaps summer like this week with highs in the 70s and 80s and overnight lows in the 50s and 60s.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 636 AM CDT Sun Apr 12 2026

Isolated to scattered showers are ongoing, but still expecting Predominantly VFR conditions through the mid-morning hours before another round of showers and thunderstorms begins to move into the area from the south/southwest. These showers are likely to drop CIGs and VSBYs into the MVFR category at KDSM/KOTM, possibly IFR at times with any heavy showers. Further north, showers are expected to remain scattered, with generally VFR conditions continuing. Winds will increase out of the south by 15z, with sustained winds of 15 to 20kts with gusts of 30 to 40 kts common. Rainfall should push east of the area by 03z. The model guidance is suggesting the possibility of low stratus /at least MVFR to IFR/ developing after 06z, something to monitor in future updates.

DMX WATCHES/WARNINGS/ADVISORIES

None.