textproduct: Des Moines

KEY MESSAGES

- Warm, dry and breezy conditions today. Elevated fire weather concerns this afternoon. Warm temperatures continue into Monday and Tuesday.

- Precipitation chances return to the state late Tuesday into early Wednesday morning. Rain and thunderstorms possible in southern and southeastern Iowa, some of which could be severe near the Iowa/Missouri border.

- Light rain transitioning to light snow over northern into north central Iowa early Wednesday morning. Minimal accumulations expected. Breezy and mild on Wednesday.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 247 PM CDT Sun Mar 8 2026

Temperatures are warming nicely over the area today, with values across the state now in the low to mid 60s as of 2 PM. Breezy winds are also increasing as the boundary layer mixes early this afternoon, with winds generally around 15 to 20 mph and gusts of 25 to over 30 mph at times. With the breezy winds and warming temperatures, we continue to monitor for fire weather concerns across Iowa today. Relative humidity values are generally in the upper 30s to low 40 percents, but a few sites in southern Iowa have fallen into the low 30 percents. A good amount of rain fell in southern Iowa on Friday, which should help mitigate serious fire weather concerns, but sunshine and winds have likely worked to dry out the fuels in southern Iowa. Therefore, burning is not recommended in these areas and a special weather statement for elevated fire weather concerns has been issued. Warm and dry conditions similar to today's will develop again on Monday, but winds won't be nearly as strong, so fire weather concerns will be less than today, despite temperatures in the low 70s central and south.

Our attention then turns toward the system arriving in the midwest late Tuesday into early Wednesday. If you were here for the previous discussions, a cutoff 500 mb low currently over the southwest CONUS was to be thanked for our zonal flow and warm, dry conditions today and tomorrow. This stagnant cutoff low is expected release back into the overall flow pattern as a long-wave trough digs in over the northwest US early to mid-week. While this is still the expected progression, the interaction between these two features has changed since yesterday. Instead of the southern stream cutoff low being pushed out ahead of the trough before phasing and merging with the northern stream trough over Iowa, the cutoff low is now being modeled to stay detached and southwest of the northern stream trough. This has had a subtle but notable impact on the forecast for Iowa. With this progression, the northern stream trough becomes the dominant feature over the state and prevents the southern stream trough (and all the gulf moisture it has with it) from fully reaching Iowa. There will still be a push of theta-e advection prior to the arrival of the northern stream trough, but that warm air and moisture is quickly shoved southward with the arrival of the northern stream wave.

As for how this affects the sensible weather forecast in Iowa, we are now seeing a southerly trend of the main QPF axis into far southern and southeastern Iowa, occurring mostly over Missouri and Illinois. The northern stream wave does still bring a push of light snow as the synoptic forcing taps into a pacific moisture stream aloft, but amounts appear light with less moisture to access than what would've been available from a plume of gulf moisture. This puts central Iowa in a "dry slot" of sorts, with the pacific stream precipitation staying in northern Iowa and north and the gulf stream precipitation in southern Iowa and south.

While the trend is shifting the main QPF axis south, the forecast has not gone completely dry for the forecast area. Rain and thunderstorms still look likely in southern and southeastern Iowa nearer to the developing surface low and it's associated cold front. The storm prediction center has issued a day 3 slight risk (level 2 of 5) for severe weather over southern and southeastern Iowa as instability creeps northward with the wave. Based on current forecast soundings, this risk looks like it may be for more elevated storms in our area, with a stout elevated mixed layer Tuesday afternoon and the cold front passing through by the time precipitation develops Tuesday evening. There may also be some heavy rain potential in southern and southeastern Iowa, as precipitation develops and tracks along a slow moving northwest to southeast oriented cold front. A marginal risk (level 1 of 5) for severe weather then extends farther north and west as a buffer to the slight risk, but if current trends continue, the marginal risk and general thunder areas are likely too far north and west. Of course, there is still uncertainty with the exact track and evolution of the system, so the current SPC outlook area does account for this uncertainty well. Fine tuning of the rain and thunderstorm threat is expected in the coming days.

Finally, as mentioned earlier, light snow chances look to develop over northern and central Iowa as cold air fills in behind the front early Wednesday morning, but will be contingent on moisture availability as the cooler, drier air mass moves in. Snowfall amounts at this time don't amount to much more than a dusting over northern Iowa, with areas farther south staying warm enough to produce a cold rain before saturation is lost through the layer. Better clarity should develop on precipitation type as we get into some of the more high resolution guidance, but potential impacts from wintry precipitation looks low given the current data.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 247 PM CDT Sun Mar 8 2026

Cooler air fills in on Wednesday as the system departs to the east through the day. With the cold air advection, height rises, and increased pressure gradient behind the departing low, breezy conditions will develop on Wednesday until the pressure gradients alleviate Wednesday night into Thursday. Temperatures Wednesday also remain mild in the 40s. However, this cooler air will be short lived as return flow develops behind the departing surface high and ahead of another approaching shortwave. This quick moving system will pass to the north of the state Thursday night into Friday, bringing more rain and/or snow chances across northern Iowa. This system will have some dry sub cloud air to deal with, but at least light precipitation looks possible. Seasonal conditions then continue into next weekend with another system being modeled to our north on Sunday at the end of this forecast period.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1034 PM CDT Sun Mar 8 2026

VFR conditions will prevail through the TAF period. Breezy southwest winds have largely tapered off this evening, however a few locations are still reporting occasional gusts. As the nighttime inversion settles in any lingering gusts should diminish, though winds aloft remain strong. This will result in a period of LLWS across all sites through Monday morning. Winds aloft taper off after sunrise and LLWS ends. Winds across the northern half of Iowa shift to out of the northeast through midday and have included this at KFOD/KMCW/KALO. For now the boundary associated with the wind shift looks to remain just north of KDSM and have maintained the southwest winds there and at KOTM through the period.

DMX WATCHES/WARNINGS/ADVISORIES

None.