textproduct: Des Moines

KEY MESSAGES

- Fog and stratus across northern Iowa tonight into Thursday. Fog over snow-packed areas could become dense.

- Warming trend continues into the weekend, topping out on Saturday with highs in the 80s.

- Brief cooldown on Sunday with recovering temperatures to start next week. Forecast looks largely dry, at this time.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 232 PM CDT Wed Mar 18 2026

Warmth and moisture are arriving from the west this afternoon with dew points above freezing melting much of the snowpack in Iowa. There's potential for snowpack to stick around in northern Iowa where the depth is higher, leading to areas of fog tonight. Dew points will remain above freezing overnight, which could create dense fog above the freezing surface of snow. Highest confidence is in Minnesota where the snowpack is thicker.

Wester CONUS ridging will continue to chew away at the northwest flow in the Upper Midwest. More of the thermal ridge's influence will be felt by Friday as +15C 850mb temperatures come into southwest Iowa, boosting highs into the 70s. As for northeast Iowa, the moisture from the melting snowpack may lead to stubborn cloud cover, hence the down trend in highs. A wave will pass Thursday night, but the dry profile will limit its effects to just a wind shift.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Issued at 232 PM CDT Wed Mar 18 2026

Southwest flow resumes Saturday and highs benefit from the WAA. Highs in the 80s will be common in the southwest half of the state, quite a change from the single digit lows earlier this week!

A front will arrive sometime Saturday night or Sunday which will drop highs back towards average to end the weekend. Precipitation chances with this boundary are low (<10%) as better saturation depth isn't achieved until the boundary passes southeast of the state. Ridging will start to recover next week with Iowa residing in the northwest flow. The amplified pattern will eventually shift, leading to another pattern change to cooler weather for Iowa in the second half of next week.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 631 PM CDT Wed Mar 18 2026

Fog potential over northern Iowa late tonight into Thursday morning, is the main aviation focus for the period. VFR conditions will persist much of the night. Fog is possible at the northern sites with the highest confidence of IFR/LIFR vsbys and cigs occurring at KMCW. Light wind through the period will mean a prolonged period of fog/cigs could persist through much of the morning over northern Iowa.

DMX WATCHES/WARNINGS/ADVISORIES

None.