textproduct: Des Moines

KEY MESSAGES

- Monitoring for potential flash flooding early this morning, but bulk of threat is further south in northern Missouri. - A lull in rain and storms bulk of daytime today, but storms return tonight. Renewed concerns for flash flooding and severe storms with all hazards possible.

- After a break in storms and rainfall on Saturday, chances return to the state later Sunday into Monday.

SHORT TERM /THROUGH SATURDAY/

Issued at 338 AM CDT Fri Jun 5 2026

Scattered showers and a few thunderstorms have been ongoing much of the night into the early morning hours with ejecting shortwave energy and a 30-40 knot LLJ keeping precipitation going. The heaviest rainfall has occurred across northern Missouri where several Flash Flood Warnings have been issued with rainfall rates of up to 1 to 2 inches per hour and rainfall totals of 2-4" or more in some locations. Although many locations outside of the far North have seen showers/storms, it hasn't been as efficient as areas further south in northern Missouri. Adjustments to the Flood Watch are likely in the next few hours.

Besides the ongoing showers/storms the other thing of note is the stratus that has developed on the back side. This cloud cover looks to hang on for awhile today and may have implications on our high temperatures and atmosphere recovery for later today. Do still expect a lull in activity from mid morning through much of the daytime hours. Besides the cloud cover, soundings still show a CAP in place and CAMs have started to key in on initiation holding off until near to after 00Z when the LLJ begins to ramp up again. The location of the boundary is going to be a significant driver in the location of convection. Tonight's training storms occurred across northern MO which was largely not captured by most models outside of the RRFS. Many, the RRFS included, would suggest far southern Iowa is the main area of storm development, but CAMs overall vary from Hwy 30 to near to south of the IA/MO border. It's reasonable to think there could be a northward shift of this boundary, but as far north as Hwy 30 seems overall unlikely at this point. Moisture transport will lead to surging dew points into the 60s and maybe even 70s. Clearing (or lack there of) may ultimately affect the extent of instability but models suggest the potential for ballooning MLCAPE of 3000-4000 J/kg but weaker bulk shear of 25-30 knots over southern Iowa. Large hail and damaging winds are certainly possible. A tornado can't be ruled out, especially near the boundary. See the SPC Day 1 Slight Risk (Level 2 of 5) for further details. Further north, in the northeast specifically, a few storms may clip this area from activity that develops in MN/WI.

Will also need to continue to watch the hydro threat with the renewed storms tonight given a similarly favorable environment with pwats 1.5-1.75", warm cloud depths, and all of the recent rainfall from tonight. Will evaluate the need for another Flood Watch following the completion of the overnight rain and where the boundary appears to set up. See the WPC Day 1 Slight (Level 2 of 4) for further details. Will also continue to watch rises on area rivers with within bank rises already ongoing or likely and minor flooding not out of the question per HEFS output.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/

Issued at 300 PM CDT Thu Jun 4 2026

Additional rounds of showers and thunderstorms are expected to continue into Saturday morning, mainly over southern Iowa in relation to where the frontal boundary is progged to generally stall for the day. Another lull is expected on Saturday with additional storms possible on Saturday night and again into Sunday as another surge of moisture pushes nwd.

Confidence on convective details at this range remain low, and the timing and location of showers and storms will be better known in the coming days as models better capture these features. Temperatures should remain at or above seasonal averages.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 655 AM CDT Fri Jun 5 2026

LIFR to VFR conditions ongoing across the state early this morning with some fog and low stratus behind the departing showers in east central Iowa. Stratus will be slow to lift over the next few hours, but overall improvement towards VFR is expected west to east mid morning to around midday. Some cloud cover looks to stick around today, though some clearing may happen at times as well. Then attention turns towards tonight when another round of showers and storms look to develop, especially over southern Iowa. Have started with prob 30 groups at KDSM and KOTM though adjustments in time and impacts are likely as confidence in storm location development increases.

DMX WATCHES/WARNINGS/ADVISORIES

Flood Watch until 7 AM CDT this morning for IAZ026>028-036>039- 046>050-057>061-070>074-081>083-092>094.