textproduct: Des Moines

KEY MESSAGES

- Scattered showers and non-severe thunderstorms are expected off and on today into Monday morning. Pockets of heavy rain may occur which could lead to renewed or continued flooding in especially areas that have already received heavy rain in the last few days.

- Warm and humid conditions build this week with many areas exceeding 90 degrees by mid-week.

- Several chances for additional showers and storms midweek.

SHORT TERM /THROUGH MONDAY/

Issued at 308 AM CDT Sun Jun 7 2026

Early morning water vapor imagery shows the upper low over southern KS/northern OK with associated showers on the east side developing with increasing theta-e advection over MO which is expected to continue to lift northward with time into Iowa this morning. As this low lifts northeastward with time today through the Midwest, there will be several pushes of shortwave energy. The end result for Iowa is several rounds of scattered showers and storms translating to off and on chances for precipitation most of the day over most of the area. It will certainly not be a complete washout with dry periods at times, but this activity will last into Monday morning in eastern Iowa as the upper low/trough lifts into the Great Lakes region into Monday afternoon. Weak to locally moderate instability may lead to thunderstorm development at times with the main hazard lightning. Severe storms are not expected with weak shear and saturated soundings. Heavy rain and localized flooding remains a concern, however, with ample moisture off the Gulf resulting in pwats of near to exceeding 2", with continued warm cloud depths. The ingredients remain in place for efficient rainfall. NASA SPoRT 10 cm soil moisture percentiles as of 7 Jun are over 90% in much of southwest and south central Iowa which makes sense with all of the recent heavy rainfall in those areas. This indicates soils are predisposed to increased runoff which could renew or continue ongoing flooding. Low lying, poor drainage, and areas with current ponding or near fuller creeks are most at risk for flooding. Additional rises on creeks and streams is likely, but river flooding probabilities remain on the lower side with only minor within bank rises anticipated. QPF totals in model guidance are not wild, generally near to less than 1" over a widespread area with pockets of 1-2". However, localized probability matched mean QPF from the HREF does show some localized pockets of 2-3" which is also seen in some of the CAMs. The location of these higher pockets is not consistent run to run or amongst models, but should these higher rain amounts fall in locations like southern Marion County with flooding ongoing, renewed flash flooding may occur. Should you encounter any flooded roadways remember to turn around, don't drown.

Temperatures today will be held down with the cloud cover and rain/storms but still in the 80s and it will certainly feel muggy with dew points in the 60s to 70s. Temperatures will be similar in the east on Monday where cloud cover holds on longer while areas to the west into portions of central Iowa warm into the upper 80s. It will feel even hotter with the higher dew points remaining sending feel-like temperatures into the low to even mid 90s, the hottest conditions in western Iowa where clearing occurs earlier in the day.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 247 PM CDT Sat Jun 6 2026

This week thermal ridging builds across the area with a western US trough ejecting bits of vorticity into the midwest, providing opportunities for precipitation. In this weak flow regime consistency amongst model guidance is low, as the GFS indicates an MCS across northern Iowa on Tuesday while the EC waits until Tuesday night and placement is across most of the state. The main trough will pass across Iowa Wednesday into Thursday, providing the next window for more organized storms. SPC has outlined a 15% risk area here for Wednesday as the trough moves across Iowa. Even here the GFS is slower compared to a more progressive EC solution.

While synoptic evolution is less certain this week in this weak flow regime, increasing heat and humidity is more certain as the thermal ridge builds. The NBM remains on the high end of the guidance envelope, but has started to come down a handful of degrees. With plenty of moisture in play, warm and humid conditions will prevent deeper mixing needed to achieve the mid 90s the NBM was progging. Even so, upper 80s to low 90s with dewpoints in the upper 60s to around 70 will make it feel quite muggy this week.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1245 PM CDT Sun Jun 7 2026

Scattered showers have spread across Iowa today, though lightning has remained limited so far. Coverage is expected to increase this afternoon along with lightning potential. Another round should lift across the area overnight, then activity tapers off Monday morning from west to east. Wind is out of the southeast at 10-15 kts, though stronger gusts are possible near showers as they pass sites.

DMX WATCHES/WARNINGS/ADVISORIES

None.