textproduct: Des Moines

KEY MESSAGES

- Isolated areas of fog possible tonight/Monday morning.

- Dry conditions are expected to remain over the next several days, with a slow warming trend through the first part of the upcoming work week.

- A signal for rain returns Thursday/Friday, though most areas may remain dry. More details expected in the coming days.

SHORT TERM /THROUGH TONIGHT/

Issued at 224 PM CDT Sun Oct 4 2026

Another pleasant day is ongoing across Central Iowa as warm and dry conditions are noted overhead, with temperatures again outperforming forecast values slightly given readings in the low 70s over much of the region, while portions of northern Iowa remain in the upper 60s. An area of high pressure is sitting over eastern Nebraska, which is responsible for the north/northwesterly winds that have occasionally been slightly breezy given rather efficient mixing as sunshine covers just about all of the state. Temperatures may warm another degree or two yet over the next few hours, before gradually cooling tonight into the mid to upper 40s for most locations, while being a touch cooler to the northeast in the low 40s.

Winds turn very light to calm tonight into Monday morning, which paired with expected clear skies across the state and areas of residual surface moisture as high pressure moves directly overhead still looks like a very favorable setup for fog development. A closer look at various short range models though still paint a variety of solutions in fog coverage, ranging from no fog anywhere, to patchy or localized dense fog over either parts of southern, central, and/or north Iowa. This leads to continued low confidence in the extent of fog formation and coverage, so have not explicitly included fog into the forecast at this time. It should be noted though that isolated areas of fog remain possible in low lying areas. Close monitoring will continue on trends in later guidance into tonight, though higher confidence may not occur until conditions show their hand into the overnight period, so something to keep in mind for those traveling Monday morning.

The beginning of the work week will see little change in the large scale pattern, as high pressure overhead continues its slow descent southeastward through the day. This will be noted by a shift in surface winds becoming more southeasterly by late morning, and persisting through the remainder of the day. Highs are forecast to reach into the upper 60s to low 70s. Into Monday night to early Tuesday, increased low-level southwesterly flow is expected to occur, ahead of an eastward passing shortwave over the upper Midwest region. With Iowa south of any potential rain shower activity from this system's passage, conditions will remain dry. Temperatures into the night will be slightly warmer than previous nights given the return of warm air advection overhead, with values generally in the 50s. Winds will be light, but too high for fog concerns, despite clear skies overhead.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 224 PM CDT Sun Oct 4 2026

A slowly building area of large scale ridging will lead to persistent upper-level northwest flow into the Midwest region throughout the remainder of the work week. Dry conditions are expected to keep hold, with warming temperatures Tuesday as increasing 850mb temps move into the state, especially west around 18-20C, and increasing winds from a tightened pressure gradient and efficient daytime mixing, leading to highs in the mid to upper 70s across Central Iowa. An area of Canadian high pressure sinks down into the region once again by midweek, with temperatures a touch cooler in the low to mid 70s forecast as winds shift north/northwesterly. By Thursday into Friday, a weak shortwave descending the eastern fringe of the aforementioned ridge looks to make its way into Iowa, with a return of mid-level moisture and forcing that will introduce the next potential for rain activity. The GFS is showing coverage over the southwest portion of the state Thursday evening into Friday, with dry conditions elsewhere given the lingering area of high pressure centered over the Ohio Valley. The Euro however has a direct west to east passage of this activity across Central Iowa Thursday afternoon to evening. Certainly notable differences between long range models, but consensus on rain returning somewhere nonetheless, so will have to monitor trends over the next several days to better pinpoint coverage and timing details. Late week into the weekend shows a building ridge over the central US, with temperatures warming overhead as highs in the mid to upper 70s are expected, along with a return of dry conditions once again, but also notably breezy.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1220 PM CDT Sun Oct 4 2026

VFR conditions are expected to continue across the terminals through the period. Outside of a small patch of upper level clouds moving through this afternoon to early evening, skies should remain clear, with northerly winds turning variable tonight into Monday before switching south/southeasterly and gradually increasing after sunrise. There remains a low probability for fog development at any terminal tonight/early Monday, though given low confidence on development/coverage specifically, have left out for this issuance and will continue to monitor trends.

DMX WATCHES/WARNINGS/ADVISORIES

None.