textproduct: Des Moines

KEY MESSAGES

- Light rain chances across northern and western Iowa (30-60%) which will continue through the night.

- Mild and cloudy conditions expected elsewhere across the state.

- Relatively active pattern with multiple rain chances through the week. Widespread rain and thunderstorm chances (40 to 70%) return on Wednesday night into Thursday morning and again Friday through Saturday.

SHORT TERM /THROUGH TUESDAY/

Issued at 224 AM CDT Mon Oct 26 2026

Looking across the state, light showers are ongoing across portions of western and northwestern Iowa. Composite radar indicates showers over portions of central Iowa, however, METAR observations show nothing is making it to the ground from these. Furthermore, sounding analysis shows dry air in the low levels, meaning this is likely virga instead of actual showers. There is some saturation as we step out in time, meaning that as we continue into the daylight hours, rain farther east (still not quite to I-35) is possible, though the expectation is that most showers will stay west and northwest.

Taking a look at what is driving this activity, at 500mb, high pressure is currently sitting over portions of the Deep South, and much of Iowa is under the influence of the associated ridge which will allow for unseasonably warm temperatures to continue for much of the state. As for the showers, a shortwave is passing through the region to the west. This same pattern can be seen at 850mb, and this high allows for a surge of gulf moisture to advect into the region. At the same time, with the ridge sitting over parts of the state, it limits the reach of this moisture to the west and northwest for today. As we get closer to sunset, a low is expected to reach into the area and help squash the ridge currently over us. After the low makes it through the area this evening, rain chances will diminish before returning Wednesday morning.

Even though widespread rainfall is not expected across much of the state, cloud cover is expected to be a bit more widespread. As such, temperatures have been adjusted to account for this. The expectations are that with extra cloud cover, high temperatures were running a little high, while overnight lows were too low. As such, lows were poked up a couple of degrees (particularly in the north) and highs were poked down a degree or two to account for this.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 213 PM CDT Sun Oct 25 2026

A southwest to zonal flow patterns sets up from Tuesday through the remainder of the forecast, with multiple shortwaves passing through at various times in the week. This will keep the forecast semi- active, with at least low chances for rain in Iowa each day Wednesday through Sunday. Wednesday night into early Thursday will be our next chance for widespread rain, primarily overnight. This precipitation may also be accompanied by some marginal instability (~500 to 1000 J/kg of MUCAPE), as well as a healthy 30 to 40 kt low level jet overnight. It's of course far too early to get deep into specifics, but if that scenario plays out, a few stronger storms could be possible in that Wednesday/Thursday timeframe, likely leaning toward elevated, nocturnal storms for our area.

Beyond the mid-week system, there is actually pretty good agreement among deterministic and ensemble guidance for another wave and healthy plume of moisture to lift up into Iowa Friday through Saturday, bringing the potential for more widespread rain and thunderstorms. Both 23.13z NBM probabilities and 23.12z LREF (GEFS, EPS, and GEPS driven) probabilities show a widespread 40 to 50% chance for greater than 0.01" of 6 hr rainfall throughout Friday into Friday evening, increasing to a 50 to 70% probability for the same on Saturday. The LREF cluster analysis is also quite impressive, with 3 of the 4 cluster solutions indicating a 50% or greater chance for rain on Saturday, and the remaining solution depicting stronger ridging and a delayed arrival of the rainfall into Saturday night or Sunday. All this to say, the current guidance is pointing toward a good chance for rain falling over the area next weekend. However, keep in mind that while ensemble models are more dispersive, they do still change as the pattern does. We will have to keep an eye on how things trend in the coming days. Regardless, the current forecast looks relatively active for Iowa through the long term.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 549 AM CDT Mon Oct 26 2026

Prevailing VFR conditions are expected through this TAF period. Light showers are ongoing across portions of western and far northern Iowa and this activity will continue throughout the day. The only TAF site that may experience showers is KMCW, although with the expectation that showers lift north by mid- morning, showers have been left as PROB30 for this site. At northern terminals (KFOD, KMCW, KALO), there is potential for MVFR ceilings just at or after this TAF period. Confidence is too low to advertise MVFR ceilings at this point, but will be monitored for future issuances. Unlike northern terminals, no impacts from MVFR ceilings are expected at KDSM and KOTM. As far as winds across the state go, they will gradually shift to being from out of the northeast to being out of the south/southeast by the end of the period, and will remain light (under 15kts).

DMX WATCHES/WARNINGS/ADVISORIES

None.