textproduct: Des Moines

KEY MESSAGES

- Seasonally warm and mostly dry conditions persist through the week.

- Breezy conditions develop north and west Friday and Saturday.

- Rain potential (20 to 30% chance) returns Saturday into Saturday night, mainly over northern and western Iowa.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 129 PM CDT Mon Oct 19 2026

Broad 500 mb ridging with surface high pressure near the Great Lakes region will generally keep conditions dry and quiet for the near future. Persistent south to southeasterly surface flow and little change in airmass overhead will keep temperatures fairly steady through the week, albeit with a 1 to 2 degree warming trend with each day of heating. Night time temperatures will remain cool with mostly clear skies, light winds and dewpoints in the 40s and 50s. Some shallow fog will be possible as temperatures cool into early Tuesday morning, primarily over northern into central Iowa. REFS probabilities for visibility less than a mile are around 30 to 50% in these regions, while HREF probabilities for the same conditions are more muted around 20 to 30% or less. Other blends have an even weaker signal. Therefore, have kept fog out of the forecast and will continue to monitor for potential through the night.

Although the pattern favors dry conditions, a few subtle shortwaves will meander through the 500 mb ridging today through Wednesday. Broadly speaking, these will be unimpactful, really only leading to slight surface pressure gradient tightening and marginally higher winds as they pass overhead. That said, some slightly better moisture aloft and shallow instability Wednesday morning has resulted in a few deterministic solutions producing light showers into southwestern Iowa. However, a deeper look into the same model soundings at that time indicate a rather stout dry layer beneath said showers. This dry layer will likely inhibit moisture reaching the surface, so not expecting more than an isolated sprinkle and have kept precipitation chances around 5 to 10% to reflect this.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 129 PM CDT Mon Oct 19 2026

The aforementioned 500 mb ridging generally persists through the second half of the work week, keeping conditions dry and warm through at least Thursday. However, an approaching northern stream trough late this week will help release the western CONUS cutoff low that has been blocking our pattern thus far. This amplified troughing will progress eastward into the Rockies and Great Plains regions through the second half of the week, shoving the ridge and coincident surface high off eastward. The amplified flow pattern will bring a better fetch of moisture into at least the western half of the state Friday into Saturday although the main surface low and better synoptic forcing generally stays north and west of Iowa. Still, some rain/showers may develop along the trailing cold front expected to move into Iowa Saturday into Saturday night. These rain chances aren't overly high (around 20 to 30% per NBM) and heavily favor northwestern Iowa given quite a bit of uncertainty with how robust the boundary will be so far from the parent low. Even if the rain doesn't come to fruition, breezy conditions are likely to develop Friday and Saturday with the increased pressure gradients, again over northern and western Iowa. Cooler temperatures begin to fill in Sunday into Monday, although the magnitude of cooling will be dependent on how robust the cold front is on Saturday.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 615 PM CDT Mon Oct 19 2026

VFR conditions will prevail through the TAF period. High clouds will pass across the area with light winds from the SSE under 10 kts. Very patchy fog is possible in northern Iowa, however confidence in occurrence is too low for inclusion at this time.

DMX WATCHES/WARNINGS/ADVISORIES

None.