textproduct: Des Moines

KEY MESSAGES

- A few showers and storms are expected tonight and Wednesday. The severe weather threat is low.

- Storms possible Saturday night and early Sunday followed but much warmer and more humid conditions for early next week.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 207 PM CDT Tue Jun 23 2026

Another afternoon of widespread cumulus development across Iowa. Increasing southerly flow over western Iowa has allowed dew points to increase into the low 60s, though diurnal mixing has led to these lowering a bit early this afternoon. That does somewhat reflect the lack of deep layer moisture currently over the state and that is any convective initiation at this time. Similar to Monday, there are some areas that have more vertical extent occurring, in particular east central Iowa with hints this will arc north/northwest towards the Waterloo and perhaps Mason City areas. This region will also have a region of 0-3 km CAPE developing along a gradually northeast lifting boundary. Also similar to yesterday, with the weak boundary and the vertical stretching component of the 0-3 km CAPE, there remains a low chance for a funnel or two, though that potential may be northeast of the forecast area soon. Overall, shower and a few non-severe thunderstorms are expected tonight as modest short wave energy moves over a region of low static stability. An upper closed low will be over northern Minnesota on Wednesday morning. This upper low will rotate a vorticity lobe into northeast Iowa, which could spark a few thunderstorms. In addition, A few storms may fire along a boundary that will be passing through the state with the focus over the southeast.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 207 PM CDT Tue Jun 23 2026

Zonal/westerly flow aloft will be in place Thursday and Friday. Still monitoring the evolution of building lower Mississippi Valley sub-tropical high and and upper low descending into the western CONUS. This will lead to a strong push of warm advection across Iowa as a steepening southwest flow develops. This may bring a few thunderstorms to the state followed by heat and humidity for Sunday and into early next week. Heat index values could approach 105 degrees in some areas. At some point, the evolution of the western trough relaxing and the sub-tropical high nudging north, may lead to the ring of fire MCS complexes rolling along the northern periphery of the sub-tropical high and potentially impacting Iowa.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1244 PM CDT Tue Jun 23 2026

VFR cumulus is developing across the state to begin the period with bases in the 4-5 kft range and will be BKN at times. The main challenge in the period is shower and a few thunderstorms possible, mainly overnight and potential for associated MVFR vsbys and cigs. A boundary will pass through late tonight and Wednesday and shift the light south/southwest winds to more westerly.

DMX WATCHES/WARNINGS/ADVISORIES

None.