textproduct: Des Moines

KEY MESSAGES

- Breezy conditions continuing through sunset. Patchy fog tonight, mainly west and some east.

- Highs in the low to mid 80s through much of the forecast.

- Storms return Tuesday afternoon with heavy rainfall possible across northern Iowa Tuesday night.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 244 PM CDT Sat Aug 1 2026

Breezy conditions continued this afternoon behind the departing low pressure. Subsidence and dryness will keep the 25kt+ gusts coming until we lose the pressure gradient and decouple this evening. High pressure will settle over the western third of the state tonight, which will lead to fog development. Confidence is low in coverage of fog in western Iowa as this part of the state received the least amount of rain the past few days. Anticipate fog to be patchy with thicker fog in river valleys. Radiational cooling in the calm winds will drop lows into the 50s. As for eastern Iowa, while the moisture is more favorable, lingering clouds and winds over 5kts will limit fog coverage for tonight, although Sunday night presents a better setup for fog.

Elevated wildfire smoke will coat the sky on Sunday, but little of it is expected to reach the ground. Height rises and high pressure will keep Sunday and Monday pleasant. Highs will be in the low 80s and winds will be light.

LONG TERM /TUESDAY THROUGH FRIDAY/

Issued at 244 PM CDT Sat Aug 1 2026

A segment of the upper low in Canada will intensify along the national border and tilt negatively across North Dakota and Minnesota. We'll see the effects of its cold front as early as Tuesday afternoon, lasting through Wednesday. Instability over 1000 J/kg sets up in the warm sector, but with favorable deep-layer shear lagging behind the boundary. Flow will be parallel to the boundary and PWATs will rise above 1.5", so there will be heavy rain potential in northern Iowa due to moisture content and training storms. This risk is currently represented with a Marginal Excessive Rainfall Outlook.

Iowa will stay in cyclonic flow through the remainder of the week which will keep precipitation chances and cooler temperatures in play.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 701 PM CDT Sat Aug 1 2026

High pressure will move into Iowa and bring light winds and diminishing cloud cover for the overnight. The wind may approach sustained 12 kts Sunday afternoon but otherwise will be mainly light.

DMX WATCHES/WARNINGS/ADVISORIES

None.