textproduct: Des Moines

KEY MESSAGES

- Isolated to scattered showers this afternoon into early evening. Severe weather is not expected, but a few funnel clouds are possible.

- Patchy fog once again possible in northeast Iowa overnight into Friday morning.

- Another low chance for scattered storms Friday afternoon- evening, mainly in southern Iowa. Trending drier for Saturday.

- High pressure is expected to set up over the central U.S. this weekend into next week, bringing much warmer temperatures Sunday and beyond.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 232 PM CDT Thu Jul 9 2026

A few weak disturbances pass through the flow today and again tomorrow keeping low chances for showers/storms in the forecast. Today, this is mainly over portions of northern into central Iowa with storms already having popped up here early this afternoon. While not expecting any severe storms this afternoon with the better parameter space to the south of the state, a brief heavy downpour, gusty wind, or some lightning is certainly possible. Additionally, there is a possibility for a few funnel clouds with the activity over north central Iowa this afternoon, as highlighted well by the SPC mesoanalysis non-supercell tornado parameter, with some low values of 0-3 MLCAPE (75-150 J/kg) overlapping with an axis of surface vorticity. Covered this with a SPS through mid afternoon, and will evaluate if additional SPS are needed beyond. Some isolated storms may pop up further south into portions of south central/southern/southeastern Iowa this evening, with all activity waning by mid evening or so with the loss of diurnal heating and with the LLJ pointed to the south of the state.

Residual moisture in especially northeastern Iowa may lead to some patchy fog again overnight with the light and variable winds expected. After a dry start to the day, scattered storm chances return to mainly southern Iowa in the afternoon. Chances remain low (around 20% again) with the higher chances to the south of the IA/MO border. Shower/storm chances wane into early Saturday for the most part with CAMS/models trending further south with activity on Saturday afternoon/evening in southern Iowa. Far northern Iowa may be scraped by some dissipating showers/storms to the north of the state early but overall, forecast trending drier after the activity Friday afternoon/evening ends. The chances for severe weather remain low Friday with again the better parameter space to our south, though can't fully rule out a stronger storm near the IA/MO border as the stronger shear overlaps with sufficient instability just into far southern Iowa. Temperatures through Friday remain more seasonal and in the 80s.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 232 PM CDT Thu Jul 9 2026

This weekend and into early next week, a mid to upper level ridge is expected to build across the central and northern plains. This will drive a warming trend alongside relatively dry conditions across the region. Highs on Saturday will approach the mid-80s with upper 80s expected by Sunday. As we head into the new work week, most of our central Iowa will push into the lower 90s. Along with the building ridge, overnight lows are expected to remain elevated in upper 60s to lower 70s. By midweek, daytime highs will peak in the lower to mid 90s as the dry spell continues. Heat indices could push mid to upper 90s in a few spots.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 632 PM CDT Thu Jul 9 2026

VFR cumulus will dissipate shortly after sunset. Widely scattered showers and a few thunderstorms have dodged terminals thus far, and will also dissipate at the same time. Monitoring for fog potential, mainly in northern terminals tonight. River valley fog also possible with <30% chance of MVFR at this time. The determining factor will be the arrival of midlevel clouds from the west. Patchy fog also possible at KDSM. Have trended vsbys at KALO and KMCW lower and into MVFR after 10z and will evaluate for worse vsbys.

Midlevel clouds move in after 12z and cumulus will again form, which could create a BKN MVFR deck for a few hours as they lift. Monitoring for additional shower potential near KOTM similar to today's.

HYDROLOGY

Issued at 232 PM CDT Thu Jul 9 2026

Main hydrologic focus is now on river flood potential within the Cedar basin, especially the Shell Rock and Cedar Rivers. High rainfall amounts occurred in the upper Cedar basin last night, and questions exist regarding the evolution of the crest as it travels downstream.

For the Shell Rock River, a quick rise has occurred during the day and the crest has been traveling downstream. It is expected in the Shell Rock area later today or this evening.

For the Cedar River, current river forecasts reflect a shorter-lived but higher crest, vs. a longer-lived but broader crest. Recognizing the potential magnitude of this event especially in the WFO La Crosse service area, the U.S. Geological Survey is planning to make some extra flow measurements which will help provide a more comprehensive picture of the stream's response for this event. This information will help fine-tune downstream forecasts for example in the Waterloo-Cedar Falls area.

DMX WATCHES/WARNINGS/ADVISORIES

None.