textproduct: Des Moines

KEY MESSAGES

- Enhanced Risk (Level 3 of 5) issued for parts of Central Iowa for late tonight into Tuesday morning. Damaging winds are the primary concern.

- Another round of severe storms possible Tuesday night into Wednesday. A Marginal Risk (Level 1 of 5) issued for all of Central Iowa.

- On and off thunderstorm chances continue through most of the week, with severe weather and heavy rain possible at times.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 307 PM CDT Mon Aug 10 2026

Monday

Visible satellite imagery shows a mix of sun and clouds across central Iowa this afternoon. Skies remain somewhat hazy due to elevated wildfire smoke advecting into the region via northwesterly flow. This smoke is anticapiated to remain aloft, limiting impacts on surface air quality. High temperatures will climb into the upper 80s to lower 90s statewide. Heat indices will reach the 90s to near 100F across southern Iowa, remaining just below Heat Advisory criteria. While rich moisture and heat will yield substantial instability (MUCAPE 4000-5000 J/kg), strong convective inhibition (CIN) will keep the atmosphere capped through the day. Storm chances increase late Monday night into early Tuesday wildfire smoke will remain aloft over Iowa through Wednesday.y morning as a nocturnal LLJ strengthens over the Central Plains. CAMS are in good agreement that a storm cluster will originate over South Dakota and northeast Nebraska, tracking into northwest Iowa early Tuesday morning.

As convection moves into northwest Iowa, extreme instability (3000- 4000 J/kg MLCAPE) will foster highly supportive environment for severe storms. Forecast soundings indicate a dry sub-cloud layer resulting in a cold pool development with the cluster of storms which will lead to a damaging wind threat. However, a robust capping inversion remains in place across northern Iowa, which may restrict storms from fully tapping into deeper instability. A critical factor to monitor is the northward extent of the LLJ. Numerical guidance remains consistent in positioning the LLJ axis across southern and central Iowa. Should the LLJ shift further north, increased warm air advection and low level shear could erode the cap, allowing for storms to tap into the instability core and escalating the damaging wind threat. The SPC has placed all of northern Iowa into a Enhanced Risk (level 3 of 5) to highlight the threat for damaging winds.

Tuesday

Showers and storms from the early morning convection are expected to clear out by early Tuesday afternoon. We begin to warm like Monday and we set our sights on another shortwave that will come out of the Rockies. As the shortwave comes across the high plains, another round of showers and storms will fire in the Dakotas. This has similar looks to what could happen tonight into early Tuesday morning. Instability looks to build into the afternoon and there appears to be enough for severe storms. We will continue to iron out the details as we get closer as Monday's nights storms could play a role.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 307 PM CDT Mon Aug 10 2026

Most of Wednesday morning will be dry but we are watching the potential for showers and storms Wednesday afternoon into Thursday. Medium range guidance look to bring ample moisture in and with PWATs over 2", heavy rainfall could occur.. Excessive Rainfall Outlooks has central Iowa in a Slight Risk for flash flooding. Embedded shortwaves look to track across the Plains and into central Iowa keeping us active with showers/storms through the end of the week.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 637 PM CDT Mon Aug 10 2026

Scattered afternoon cumulus around 2500 to 3500 ft are slowly dissipating early this evening, leaving primarily VFR conditions through the evening. However, we will see showers and storms increasing after midnight, primarily over northern Iowa. Confidence is moderate to high that storms will move through the area early Tuesday morning, but exact timing is less certain. Therefore, TAFs capture the currently expected time windows for storms at KFOD, KMCW and KALO and will be refreshed as confidence increases. Strong winds could also accompany the line of storms, and this is referenced in the TEMPO groups. Showers or storms are possible as far south as KDSM, depending on the strength of the system, but confidence is lower so have opted for PROB30 SHRA at this time.

After the storms move out tomorrow morning, VFR conditions are expected through the remainder of the day with light and somewhat variable winds.

DMX WATCHES/WARNINGS/ADVISORIES

None.