textproduct: Des Moines

KEY MESSAGES

- Scattered storms persist across northern Iowa this afternoon. Additional scattered thunderstorms develop in northern Iowa Thursday morning. The pattern continues with morning storms expected in parts of northern Iowa each morning through at least Saturday.

- Heat and humidity continues this week and through the weekend. Hottest conditions in southern to central Iowa where a Heat Advisory is in effect through at least Friday.

SHORT TERM /THROUGH FRIDAY/

Issued at 243 PM CDT Wed Sep 2 2026

Scattered thunderstorms have persisted across north central Iowa all morning and into this afternoon. Storms were fueled through the morning by the low level jet, which is only just beginning to diminish after 18z. Those storms have continued to bubble along the theta e gradient in place and are expected to continue into the afternoon. The severe threat is low, however storms could create gusty winds as soundings show dry air through the low levels.

Storms redevelop across northern Iowa once again early Thursday morning and are expected to percolate along the theta e gradient through midday. The low level jet axis is expected to be oriented west of the area and that will help to reduce forcing into the area. With very little shear available severe chances are low, though some gusty winds are possible with stronger cores. The story continues with overnight/early morning storms developing into Friday morning as well. This round will be aided by a weak embedded shortwave rounding the thermal ridge and providing additional forcing. The track of this embedded wave is expected to track across Minnesota and slide south across Wisconsin and into Illinois, skimming into northeast Iowa but largely missing Iowa to the east. Damaging winds are the primary concern storms developing on Friday morning and continuing into the afternoon with that shortwave.

Heat continues this week and the heat advisory has been extended through Friday evening. The large thermal ridge dominating the central US extended through the southern portions of Iowa, allowing heat indicies to reach the upper 90s to low 100s each afternoon. There is little in the way of overnight relief as low remain muggy and in the upper 70s to near 80. In fact, Des Moines has broken warmest minimum temperatures records multiple times this week and may continue to do so this week. From central to northern Iowa storms along the peripheral of the ridge have kept temperatures lower.

LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/

Issued at 243 PM CDT Wed Sep 2 2026

Nocturnal and morning convection, mainly across northern Iowa, is expected to continue each day through at least Sunday morning. With only modest forcing severe chances each day are fairly low. The next more organized convection chance is not until early next week and that will help to squash the ridge and bring at least some relief to temperatures for a few days. Until then, heat continues this weekend with heat indicies in the upper 90s to low 100s across southern and into central Iowa. With the holiday weekend coming up it is important to remember heat safety for any outdoor plans that are in place. Minimize time outside, hydrate, and take breaks in the shade. By late week the thermal ridge looks to rebuild with heat and humidity lifting back north into the area, along with continued scattered storm chances.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1235 PM CDT Wed Sep 2 2026

A broken line of storms has been nearly stationary across northern Iowa through the morning, missing all TAF sites so far and that is expected to be the case as storms continue this afternoon. If coverage expands then KFOD/KALO could see impacts and this will be monitored. Then early Thursday morning scattered thunderstorms are renewed across northern Iowa. Prob30 group were maintained for this hazard at KFOD/KALO/KMCW.

DMX WATCHES/WARNINGS/ADVISORIES

Heat Advisory until 7 PM CDT Friday for IAZ057>062-070>075- 081>086-092>097.