textproduct: Des Moines

KEY MESSAGES

- Scattered thunderstorms remain possible this morning over northern and north central Iowa, with wind gusts and heavy rainfall the main concerns.

- Additional showers and non severe storms are possible (20-30%) this afternoon to early evening.

- Drier conditions to start the work week, then showers and storms return to the forecast by midweek.

SHORT TERM /THROUGH MONDAY/

Issued at 217 AM CDT Sun Jul 5 2026

Most areas remain on the dry side across Central Iowa early this morning, with a few reports of haze and/or smoke likely due to firework activity from the evening celebrations. Lowest visibilities related to this haze has been down to around 2 miles in and near Des Moines, with otherwise values around 6 miles or greater and expected improvement later this morning as mixing gradually increases. Otherwise, the primary focus area at this current time are the scattered showers and storms that have slowly been descending south/southeastward into the far northern portions of the forecast area from southern Minnesota, which have had quite a bit of lightning and at least a few sub-severe wind gusts in the 40s. This activity is likely due to the presence of the upper level shortwave that is overhead the region, paired with surface moisture convergence. While instability values of 1000-2000 J/kg are present overhead, weak shear and poor lapse rates will allow for storms to be pulsey in nature, with the main concern being additional sub- severe or less gusts and heavy rainfall due to PWATS over 1.5 inches present. Efficient rainfall of 1-2 inches is possible (amounts which have been noted with the activity so far in northern Iowa). Over the next few hours though, the expectation given model trends is that the mid to upper level forcing for lift will continue to weaken, which will ultimately lead to storms fizzling out before sunrise and dry conditions returning across the area.

The aforementioned upper level shortwave will continue to gradually shift further eastward through today, with otherwise surface weak high pressure extending into Iowa that will lead to light winds out of the northeast and high temperatures reaching into the low to mid 80s under partly cloudy skies. As temperatures peak late morning into the afternoon and instability increases into the 2000-3000 J/kg range, there comes a low potential (20-30%) over the forecast area for scattered showers and storms to develop. Relatively weak flow remaining overhead and less than favorable lapse rates though will lead to little concern for strong to severe storms, as any will generally pulse up and down, if development can even occur given lower level dry air per soundings. If storms can develop, gusty winds would be the main concern as any cells collapse into the drier air, along with heavy rainfall that could quickly produce appreciable amounts around an inch or so. Any storm activity would diminish through the evening, with dry conditions expected as skies turn mostly clear and temperatures gradually fall into the 60s.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 246 PM CDT Sat Jul 4 2026

Drier conditions are expected to start the week. The next short wave arrives late Tuesday night into Wednesday and will bring thunderstorm chances to northern Iowa. Westerly/zonal flow will persist the rest of the week with another embedded short wave passage around Friday.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 632 AM CDT Sun Jul 5 2026

VFR conditions are expected to continue across the terminals through the period. Current cloud cover is expected to depart the area over the next few hours, though followed by the development of widespread cumulus development into this afternoon that could lead to near MVFR ceilings at times. Otherwise, there is a low chance (20-25%) for pop up thunderstorms this afternoon, though confidence is not high enough in this issuance to include at any specific terminal, and will need to be monitored as conditions evolve today. Winds will remain light out of the northeast, then turn more variable into Monday morning.

DMX WATCHES/WARNINGS/ADVISORIES

None.