textproduct: Des Moines

KEY MESSAGES

- Spotty showers this afternoon, mainly east of I-35.

- Frost and Freeze headline are in effect Saturday for overnight and morning temperatures in the low 30s.

- Isolated shower possible in northeast Iowa Sunday morning, then isolated thunderstorm possible in southeast Iowa Sunday late afternoon/evening.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 143 PM CDT Fri May 1 2026

A weak shortwave is passing across Iowa today. This morning this resulted in very light, spotty showers in eastern Iowa. By this afternoon daytime heating has created marginal increases in stability, allowing for a few more showers to develop as the wave pushes southeast. These showers will sink towards southeast Iowa by early evening as the wave moves southeast, then diminish in coverage after the sun sets and instability is lost.

High pressure settles across the area overnight and on Saturday behind this shortwave. With light wind and clear skies overnight this will be a good radiational cooling setup. Temperatures are expected to drop off into the low to mid 30s overnight. There is the potential for temperatures to drop even further overnight closer to dewpoints in the upper 20s if winds go completely calm. As such, widespread frost and freeze headlines are in effect for the area overnight and Saturday morning. Quiet conditions last much of the rest of the day Saturday with highs into the low 60s. By late Saturday a quick moving embedded shortwave will scoot across northern Iowa, skimming eastern Iowa Sunday morning. Scattered light showers are anticipated with this wave. This wave, along with the thermal ridge shifting east, will induce warm air advection into the area Sunday and allow temperatures to warm to the upper 60s and low 70s. The weak boundary from the morning wave may see redevelopment in the afternoon towards southeast Iowa, though much of this activity is expected south and east of Iowa as the wave exits the area.

LONG TERM /MONDAY THROUGH THURSDAY/

Issued at 143 PM CDT Fri May 1 2026

The long wave trough that brought multiple waves across the midwest late this week and through the weekend will finally push east early next week. A cold front will push across Iowa late Monday into Tuesday. Will daytime temperatures will warm into the mid to upper 70s, by Tuesday highs will be back to near 60. Showers and thunderstorms are expected along the cold front, mainly in central to southern Iowa. These cooler temperatures will hang around through mid week. The main trough axis finally pushes across Iowa on Wednesday into Thursday. Better forcing is generally south of the area, though expect precipitation into Iowa with this passage. Warmer air is expected to lift back into the area by late week as the trough pushes east.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1228 PM CDT Fri May 1 2026

Scattered showers are beginning to form across northern and central Iowa which may bring occasional sporadic gusts of 15 to 20kts. Persistence in these gusts is not enough to warrant a mention in the TAFs. Because of the scattered nature of the showers, PROB30 has been introduced at most sites to account for any light rain that may occur. Otherwise, northerly winds will gradually shift to the west, with DSM and OTM beginning to shift back to the north toward the end of this TAF period.

DMX WATCHES/WARNINGS/ADVISORIES

Freeze Warning from 1 AM to 8 AM CDT Saturday for IAZ004>007- 015>017-023>028-033>037-044>047. Frost Advisory from 1 AM to 8 AM CDT Saturday for IAZ038-039- 048>050-057>062-070>075-081>086-092>097.