textproduct: Des Moines

KEY MESSAGES

- Very mild temperatures with near record highs through Monday.

- Precipitation possible central and south Tuesday night/Wednesday.

- Widespread showers and storms Wednesday night/Thursday followed by much cooler weather.

SHORT TERM /THROUGH TONIGHT/

Issued at 344 AM CDT Sun Oct 11 2026

Early morning surface analysis continues to show a very slow-moving surface wave gradually approaching the region. Presently, this feature is centered over international waters near northern Minnesota, riding along a baroclinic zone with multiple mesoscale lows extending back into the higher terrain of western Wyoming. Surface high pressure remains anchored over the Four Corners, exerting its influence across much of the central CONUS. Meanwhile, Post-Tropical Cyclone Isaias is tracking slowly northward toward the Ohio River Valley. Locally, high pressure dominates with clear skies and early morning temperatures ranging from the lower 60s in the southeast to near 70 in the north and west, where boundary-layer mixing persists.

Today will bring weather similar to Saturday, with high temperatures forecast to climb into the mid-80s once again. As noted in yesterdays discussion, maximum temperatures could approach record- breaking values, and this forecast package projects a few records to fall. The record high of 86 at Des Moines is in jeopardy, along with 85 at Mason City, 86 at Ottumwa, and 84 at Lamoni. The upper-level trough and associated surface low will continue their slow approach today, but the local forecast area will remain dry. Winds will stay breezy due to a persistent surface pressure gradient and low-level jet support. Gradual low-level moisture advection into the region will help mitigate fire weather concerns, though elevated risks remain.

Beginning late Sunday night into early Monday morning, a cold front will begin diving into the area. Saturation ahead of the boundary appears likely, but omega remains weak, resulting in negligible PoPs for the local forecast area while stronger forcing and higher PoPs reside closer to the surface low center in Minnesota. Outside of precipitation chances, high temperatures on Monday will remain above average, climbing into the mid-80s; however, temperature records are expected to remain safe.

Unseasonably warm and breezy conditions will persist across the region today as an upper-level trough and cold front slowly approach from the north, threatening several daily high-temperature records. While elevated fire weather concerns remain, increasing moisture advection will offer partial mitigation today. A decaying cold front will bring some cloud cover and increasing moisture into Monday morning but weak atmospheric lift will keep shower chances negligible locally, maintaining warm and dry conditions through the start of the workweek.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 155 PM CDT Sat Oct 10 2026

Subtropical high pressure will lift into the lower Mississippi River Valley Tuesday and Wednesday while upper low pressure enters the Four Corners region. This will amplify the southwest flow over Iowa. Despite this evolution, the Gulf Moisture stream will be veered to the southeast of Iowa as surface high pressure moves into the Northern Plains. This is trending precipitation chances southward Tuesday and Tuesday night. The greater chances for precipitation are later in the week from Wednesday night into Thursday as the main upper level system lifts out of the southwest. Temperatures will gradually cool through this period as well. Broad northerly flow will follow the upper system passage and usher a cooler, fall like airmass into to Iowa for the end of next week.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 634 AM CDT Sun Oct 11 2026

VFR conditions are expected through the period. Winds will continue to dominate the forecast as LLWS is forecast for the next couple hours before diurnal mixing negates LLWS. Mixing will persist through the day before an inversion sets up after 00Z/Monday allowing for LLWS to re-enter the TAF. Winds will be predominately out of the south with sustained winds from 10 to 15 knots and gusts upwards of 25 knots.

DMX WATCHES/WARNINGS/ADVISORIES

None.