textproduct: Des Moines

KEY MESSAGES

- Cooler temperatures in the upper 70s through the work week before another warmup into the 90s this weekend.

- Spotty showers possible in southwest Iowa today, then more widespread rain Thursday evening into Friday in central to southern Iowa.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 207 AM CDT Wed Jul 22 2026

High pressure has settled across the Dakotas and Minnesota, keeping the area clear and dry, while a surface low sits across western Nebraska early this morning. The low will gradually shift east through today with precipitation reaching western Iowa later this afternoon. High pressure is creating a fairly dry air mass across Iowa and the incoming low will struggle to saturate. While a few spotty showers are possible in far west/southwest Iowa this afternoon most of the area will remain dry today. That high pressure will also be effective in keeping the area around 10 degrees below seasonal average with highs in the upper 70s this afternoon.

Cooler temperatures in the upper 70s continue on Thursday and Friday. On Thursday an embedded shortwave rides along the western US thermal ridge, sliding across Nebraska and into Iowa by Thursday evening. The plume of moisture transport shifts back into Iowa aided by the increasing low level jet , helping to saturate sounding profiles by Thursday evening. Precipitation is expected to last through the overnight and into Friday morning before clearing out in the afternoon. Warm cloud layers are very deep at 4000-4500+ with PWATs at 2-2.25" which will likely result in efficient rain production. Mature crops should be able to handle several inches of rain, but heavier amounts in town could result in hydro problems overnight and on Friday morning.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 210 PM CDT Tue Jul 21 2026

A stronger wave looks to move across the top of the ridge by Thursday evening and bring us our next chance for meaningful precip. Instability will be quite limited so severe weather is unlikely, though some thunder is possible Thursday night into Friday morning in southern Iowa. The nocturnal LLJ returns to our vicinity during the Thursday overnight, with the nose centered over southwest Iowa. This should erode the dry air and allow the quite saturated mid levels to rain down to the surface. The main story will be QPF amounts. WPC has southwest Iowa in a marginal ERO for Thursday and Friday, and PWATs are well over 2 inches. There is a large QPF spread across the models, but a few give spots in southern Iowa 1-2 inches of rain. By the weekend, the ridge intensifies over the Dakotas, bringing us another period of heat. We may breach the 90s again on Saturday, and Sunday/Monday look to be the warmest as a more substantial EML is advected in.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1045 PM CDT Tue Jul 21 2026

VFR conditions will continue through the end of this TAF period. Skies will remain mostly clear overnight with winds under 8kts at all terminal sites. There is a slight chance of haze tomorrow morning in SW Iowa, but it will not impact terminal sites. There is also a chance for a morning shower in southwest Iowa but confidence remains low due to dry air at the surface. However, as daytime heating resumes, cumulus clouds could return to Central Iowa tomorrow afternoon.

DMX WATCHES/WARNINGS/ADVISORIES

None.