textproduct: Des Moines

KEY MESSAGES

- Showers and drizzle ending by evening, temps in the 50s overnight.

- Partly to mostly cloudy on Monday. A stray shower is possible. Highs in the 70s.

- Next chance for showers and thunderstorms is late Tuesday afternoon into Wednesday morning. An isolated strong/severe storm is possible. Below average temperatures will continue for most of this week with highs in the 70s to lower 80s.

SHORT TERM /THROUGH MONDAY/

Issued at 153 PM CDT Sun Jun 21 2026

The rainfall event will continue to wind down this afternoon into this evening, and the Flood Watch was cancelled around 1pm. Weak upper forcing and lingering moisture convergence will allow for light showers or drizzle to persist in the east through late this afternoon. The highest storm total rainfall amounts ranged from 2" to 3" over portions of southern and central Iowa, which is actually pretty impressive considering the lack of convective elements and virtually no lighting. A few rivers are experiencing within bank rises, but no river flooding is currently anticipated. With the abundant cloud cover and rainfall, temps struggled to move today, with readings remaining in the 60s in most places as of 2pm. In fact, these readings are very close to the record "low max" temps for the date (DSM is 63F, ALO is 62F. both from 1902). Not the greatest conditions for Father's Day, sorry to all Dad's out there!

Tonight, sfc high pressure will build into Iowa resulting in light and variable winds. Depending on the amount of clearing, the light winds and residual low level moisture is a favorable setup for at least patchy fog to develop. Guidance is not terribly bullish attm, but something will need to monitor this evening.

Monday...the sfc high remains in place over IA and much of the Midwest with upper level shortwave ridging developing by afternoon. Model soundings and time sections show a "dirty" look, with moisture remaining in both low and mid-levels. Thus, expecting a partly to mostly cloudy day with a coolish highs in the 70s. Several CAMs (e.g. HRRR) due try to develop isolated showers tomorrow afternoon as very modest instability develops. These rogue showers would be most likely across northern Iowa.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 153 PM CDT Sun Jun 21 2026

The synoptic pattern this week will begin with a predominately northwest upper flow regime over the upper Midwest and Corn Belt, with upper ridging along the west coast and the development of a broad trough along the far northern CONUS.

On Tuesday, a weak sfc low will develop over ND/MN with a weak cold front trailing swd into the Plains. Much of Tuesday will be dry, but modest moisture return ahead of the front may produce weak/moderate instability by late afternoon into the evening, especially across northern/western Iowa. This will lead to a 30-60% chance of showers/storms, mainly after 00Z Wed. The SPC has introduced a Marginal Risk (Level 1 of 5) for late Tuesday. Thinking the best chance for severe weather is likely north and west of this forecast area (supported by latest AI Guidance) but something to monitor. Highs on Tuesday will remain in the 70s.

Mainly dry conditions are expected Wednesday and Thursday, and with the persistent northwest flow, temperatures will remain below average. The next precipitation chances arrive Friday into the weekend as additional low amplitude shortwaves track through the region. There are the usual timing/placement uncertainties at this timeframe, so the typical 20-40% PoPs seem reasonable for now. By the weekend, a deeper upper trough is forecast to develop over the western US, resulting in a transition to a more southwest upper flow. This will usher in a more typical warm and humid summer pattern with highs rebounding back to near or above normal - 80s to lower 90s.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1231 PM CDT Sun Jun 21 2026

Mostly VFR with some MVFR conditions are expected at KFOD, KMCW, and KALO with IFR conditions expected at KDSM and KOTM. Showers are making their way out of the area and should be clear by 00z. Behind the showers, MVFR to IFR ceilings are going to move in at southern terminals while northern terminals will see MVFR to VFR ceilings. Uncertainty exists with how long these ceilings will last. Should there be any clearing overnight tonight, conditions are favorable for fog to develop across the area. At this time, there is too much uncertainty with potential coverage of fog and how much clearing takes place to mention it in the TAFs. Otherwise, light winds are expected for most of the period. Overnight winds will be light and variable before taking on an easterly direction towards the end of this TAF period. Through the day tomorrow, scattered cumulus is expected and will be addressed in future issuances.

DMX WATCHES/WARNINGS/ADVISORIES

None.