textproduct: Des Moines

KEY MESSAGES

- Winds gradually diminishing this afternoon and evening, then becoming light and variable tonight.

- Another quick shot of light snow from Tuesday afternoon into Tuesday night. Highest chances and forecast amounts of 1-2 inches in northern and northeastern Iowa, with more modest chances and lighter amounts in central and southwestern Iowa.

- Significantly warmer at the end of this week, especially on Friday when highs will soar into the 70s and possibly even lower 80s across much of the southwestern half of Iowa.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 209 PM CDT Mon Mar 16 2026

The winter storm system that affected our area yesterday and last night is departing to the east, replaced by a surface high pressure ridge building in from the west this afternoon. Clouds have gradually cleared to the east as well; winds are slowly diminishing but should die off more quickly after sunset. As winds go nearly calm overnight beneath clear skies we should radiate nicely, particularly in areas where snow covers the grass, and have maintained low temperatures below median guidance in the single digits below zero north to single digits above south. The silver lining is that with such light winds, hazardous cold/wind chills will not be an issue again overnight.

On Tuesday the surface ridge will move quickly away to the east and we will see a return of southerly low-level flow and slow warm air advection. Above the surface, a broad swath of increasing moisture, isentropic lift on the 280K-290K surfaces, and frontogenetical forcing will promote thickening clouds and the development of light precipitation, mainly over Minnesota but to some extent across Iowa as well. Forecast soundings saturate quickly, however the forcing for ascent is relatively modest and transient. Also, at least initially a stout near- surface dry layer should inhibit any precipitation from reaching the surface. Models are nearly unanimous in saturating this layer and producing precipitation across northern Iowa, but in central and southern Iowa it is less certain as the low-level dry layer stubbornly hangs on. Even so, some precipitation is very likely in our north and northeast and have increased POPs to categorical (80%) in those areas, with lower (30-40%) POPs in the southwest where forcing is weaker and the near-surface dry layer stronger. Also refined the onset timing of precipitation which will be slowed by having to overcome the aforementioned dry air, with POPs now maximized between the early afternoon and early nighttime hours. Forecast soundings generally support snow as the precipitation type, though there may be some brief periods of rain where temperatures are warmer (mainly southwest) or freezing drizzle if ice introduction is lost (though these would be brief and of little to no accumulation). Accordingly, forecast snow amounts range from a dusting in central and southern Iowa up to a quick 1-2 inches in our northern and northeastern counties. With modest breezes during this time impacts should be minimal, but roads may still become slick and snow covered in some areas by Tuesday afternoon and night.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 209 PM CDT Mon Mar 16 2026

The long term forecast period is not only generally dry (less than 20% precipitation chances) and overall quiet, but also features a significant warm spell later this week. By Wednesday morning a 500 MB trough will be moving away from Iowa to the east (having just contributed to the Tuesday/Tuesday night snow discussed in the short term section above), while a large 500 MB high pressure dome will be building in the southwestern U.S. As that dome further strengthens and expands in the latter half of this week, it will bring potentially several days of record heat to the southwestern states, and will also increasingly exert its influence toward the Midwest and Iowa. This will result in a gradual warming trend in our area from Wednesday through Thursday, though it may be slightly tempered by a relative lack of low-level flow/mixing, as well as some mid/high level clouds at times as we remain on the extreme northeastern periphery of the 500 MB ridge. Even so, the current forecast high temperatures on Wednesday range from 40s in our northeastern counties to lower 60s in our southwest, and on Thursday range from the 50s northeast to lower 70s southwest.

Friday and Saturday are likely to be the warmest days of the week, as the 500 MB height dome will be at its most influential and mixing depths should be at their highest per forecast soundings. On Friday afternoon the GFS mixes from around 850 MB (where the temperature is predicted to be around +11C) down to the surface, with little sign of clouds. If this comes to fruition then highs will soar into the 60s northeast and roughly mid to upper 70s central and southwest. Des Moines may approach its daily record high of 79 for March 20th, though the ingredients will have to come together nearly perfectly to reach that mark. Even if we do not reach those levels however, unseasonable warmth appears to be a slam dunk with the ECMWF EPI indicating nearly 90% of ensemble members predicting temperatures well above normal on Friday. In any event, the several days of warm weather heading into this weekend will be welcomed by most area residents, particularly after the cold of the last 24 hours and tonight. Early indications are that a cool front will temper the warmth as it comes through on Saturday night or Sunday.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 628 PM CDT Mon Mar 16 2026

Broken MVFR clouds continue to stream across the northeastern portions of the area early this evening, impacting KMCW and KALO. Expectation is for this cloud deck to lift and disperse through the next few hours, giving way to VFR conditions overnight. A few flurries and occasional blowing snow has been reported in these same areas, but this potential should end as clouds disperse and winds diminish tonight. Winds become light by early Tuesday morning, steadily switching from northwesterly tonight to westerly Tuesday morning and finally southerly by mid-day Tuesday. Winds will increase to around 10 to 15 kts out of the south with gusts around 20 kts tomorrow afternoon and early evening. Light snow will also move through the area tomorrow evening, with the greatest chances near KFOD, KMCW and KALO, but brief snowfall could be seen as far south as KDSM and KOTM late in the period Tuesday.

DMX WATCHES/WARNINGS/ADVISORIES

None.