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 TUESDAY/

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 /TUESDAY NIGHT THROUGH SUNDAY/

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 /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1119 PM CDT Sun Jun 21 2026

Low clouds have largely cleared the area, except in northeastern Iowa around Waterloo where intermittent MVFR ceilings are still being observed. Meanwhile, mid/high level clouds are spreading in from the west/northwest, but eroding as they reach central Iowa, so confidence is low in the degree of cloud cover at any given location overnight as these trends are not being well- handled by short-term models. If any areas are able to remain clear for several hours toward sunrise then fog may be able to form, most likely at Waterloo and possibly Mason City. Have included a TEMPO group for fog at Waterloo only, but amendments will likely be needed to handle these trends in near real-time. Conditions should improve to VFR everywhere by mid-morning Monday and beyond.

DMX WATCHES/WARNINGS/ADVISORIES

None.