textproduct: Des Moines

KEY MESSAGES

- Lingering showers end by daybreak. Lull in activity through early afternoon before scattered thunderstorms develop again across portions of central into southern Iowa later this afternoon into evening. Some stronger storms could have gusty winds or hail. Will also continue to monitor the hydro threat with activity expected over the same areas as recent days.

- Heavy rain is a concern for renewed showers and thunderstorms on Sunday into Monday.

- Warm and humid conditions largely continue with Sunday the coolest day and mid-week looking the warmest with many areas exceeding 90 degrees.

SHORT TERM /THROUGH TONIGHT/

Issued at 329 AM CDT Sat Jun 6 2026

It was a very active late evening and early overnight over south central into southern Iowa with several severe thunderstorms causing damaging wind gusts of 60-70 mph and hail up to 2" in some locations. In addition, these storms were efficient rainers with several locations receiving 2-4", and a few locations around 4-5", and an isolated location near Pleasantville with a personal weather station that logged nearly 6". Several flash flood warnings were issued and these areas of south central into southern Iowa will be watched closely over the next several days with renewed chances for rain daily through Monday. As noted in the previous hydro discussion, soils are saturated and predisposed to increased runoff, with many smaller streams and creeks with reduced capacity after several days of rain. Many of the same areas received this excessive rainfall tonight, and unfortunately we are not done yet with more rain in the forecast this weekend.

The upper trough continues to shift eastward today with upper ridging moving in through the day. Any lingering showers/storms are expected to end by about daybreak with another lull in activity through early afternoon. More sunshine is expected today, especially north which is where temperatures are expected to be warmest, in the upper 80s. Further south, cloud cover will hold temperatures a few degrees down, but still in the mid 80s. Dew points remain high, in the 60s-70s making it feel humid and with the higher dew points in the south, sending feel-like temperatures close to 90. Although shortwave energy doesn't really start to kick in again until late Saturday night (far south) into Sunday afternoon (much of the area) CAMs continue to suggest renewed storm development in southern Iowa likely along a lingering boundary with not much else for forcing. The environment will be characterized by strong instability with MLCAPEs of 2000-3000 J/kg + but with very weak shear less than 20 knots. This will make it difficult for storms to organize keeping activity pulsey and largely diurnally driven, but stronger storms could have hail or gusty winds. QPF amounts are not particularly high given the expected pulsey nature and generally less than 1". This typically would be very manageable but with it being over the same areas as the last several nights, the hydro threat is heightened despite the lower expected rain amounts. Will certainly evaluate the need for additional flood watches tonight into Sunday. Should any storms linger into the night, the more favorable jet is to the west to northwest of the area but moisture transport continues to be favorable and even increases into Sunday morning with CAMs and global models all hinting at additional isolated to scattered activity moving or developing to the north (central to northern Iowa) into early Sunday morning before the more widespread activity blossoms into Sunday afternoon, as discussed further below.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 1214 PM CDT Fri Jun 5 2026

An upper level cutoff low across the southern plains on Sunday morning will lift into the midwest by the afternoon and evening. Deep moisture transport out of the gulf increases into Iowa, especially southern Iowa. Scattered daytime showers and thunderstorms may linger with renewed thunderstorms developing in the evening and continuing overnight into Monday morning as the upper low/trough tracks across Iowa. The threat for severe storms appears low at this time with deeply saturated soundings exhibiting very little instability (500 J/kg) or shear (20 kts or less). The primary concern this period will be additional heavy rain across southern Iowa, following heavy rain Thursday and Friday nights. With PWATs near 2 and deep warm cloud layers exceeding 4000m, expect efficient rain fall across southern into central Iowa.

The upcoming week should be mainly dry, though few weak waves skimming the area could bring renewed showers or thunderstorms to the area. Heat builds through the week as the thermal ridge expands and shifts into the midwest. While NBM guidance has rockets up into the mid to upper 90s by the middle to end of next week, this seems overdone from over mixing and with weak waves thwarting the highest temperatures. NBM has been on the highest end of the guidance envelope the past several cycles and will continue to need nudging down unless the pattern changes. Despite the overzealous NBM, temperatures will still be quite warm and reach the upper 80s to low 90s. The next more organized chance for precipitation arrives late in the week around Thursday.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 641 AM CDT Sat Jun 6 2026

Precipitation has come to an end across the area and widespread VFR cloud cover is gradually diminishing. Scattered VFR clouds will last for much of the day. A weak boundary is across central Iowa this morning with variable light wind around it. By late morning into the afternoon winds shift around to out of the southeast. Late tonight showers and thunderstorms lift into Iowa out of Missouri. A stray storm or two is possible in central Iowa in the evening, from 00-06z, then the main area of scattered showers and storms lifts into southern Iowa. There is low confidence in occurrence and placement of earlier isolated storms, so have kept from TAFs. Have introduced a prob30 group a KOTM for the main are of convection expected late overnight and Sunday morning.

DMX WATCHES/WARNINGS/ADVISORIES

None.