textproduct: Des Moines

KEY MESSAGES

- Scattered showers and storms this afternoon into evening mainly in southern Iowa. While an isolated strong storm is possible towards the IA/MO border, widespread severe weather is not expected. Spotty heavy downpours are likely. Conditions are also favorable for funnel clouds.

- Patchy fog possible again overnight into early Saturday in mainly western and northern Iowa, where skies clear faster.

- A strong upper level high pressure ridge will set up over the central U.S. this weekend into next week, bringing mostly dry conditions and very warm temperatures Sunday and beyond.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 237 PM CDT Fri Jul 10 2026

Main focus in the short term is on the MCV out of Nebraska this morning has developed showers and storms over northern Missouri into southern Iowa as expected early this afternoon. The environment is fairly similar to yesterday with around 1500 J/kg of MLCAPE, higher at the surface, though with weak capping still in place. Shear remains very weak, less than 10 knots in much of the area, with slightly higher values closer to 25-30 knots right along the IA/MO border. With the weak shear, and as noted in the previous discussion, it will be difficult for storms to organize and maintain the further north you go (north of about I-80). South of I-80, and especially right along the IA/MO border the parameter space is a bit better and would be the location should any stronger storms be able to develop/maintain in our area with a risk for some brief hail or gusty winds. This is in line with the SPC Day 1 Level 1 of 5 Marginal Risk that goes up to the IA/MO border. In between the IA/MO border and about I-80, we have already seen showers/storms initiate and while the severe threat remains low in this area with the conditions already discussed, the weak shear is leading to slow moving storms which could easily lead to some locations receiving some heavy downpours and rain totals adding up quickly given the nearly stationary to slow moving nature of the storms and pwats of around 1.5". Some minor flooding could be possible should one of these storms occur over a poor drainage or urban area, though widespread flooding is not expected with this area of southern Iowa most able to take rain with 3 hour flash flood guidance closer to 3- 4". Severe storms and flash flooding already ongoing in northern Missouri are not far away from our southern coverage area border so we will certainly watch these storms and rainfall amounts closely. Just like yesterday as well, the environment does remain quite favorable for funnel clouds with an area of overlapping surface vorticity and 0-3 CAPE in southern to portions of eastern Iowa. This is once again highlighted well with the non-supercell tornado parameter in SPC Mesoanalysis with a few funnel clouds already reported with developing showers in southern Iowa early this afternoon. This will likely continue with developing showers until around sunset. Have covered this area with a SPS for the funnel clouds.

Storm coverage today will largely be diurnally driven and should start to wane by around sunset. Dry conditions return late this evening and continue through Saturday, outside of a stray shower in the south, with models continuing their southerly track for storms on Saturday as noted this time yesterday. The residual moisture could lead to patchy fog development again overnight into early Saturday as skies begin to clear with the light winds expected to be in place. The most likely locations are in the north and west with cloud cover hanging on longer in the south and east. Temperatures remain more seasonal through Saturday with highs in the mid 80s.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 237 PM CDT Fri Jul 10 2026

Dry and increasingly warm conditions are forecast from Sunday through much of next week as an upper ridge builds and tracks eastward through at least mid week. High pressure at the surface will keep winds light and skies mainly clear outside of some diurnal cumulus at times. Southerly flow starts to return early in the work week leading to warming temperatures in the upper 80s to low 90s Tuesday and beyond with heat indices topping out around the mid to occasionally upper 90s at times. Certainly warm, but looking to be below heat headline criteria. Precipitation chances then return later in the week in at least the east into Friday, though at this time range there is still a fair amount of model spread and plenty of time to refine the forecast.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1233 PM CDT Fri Jul 10 2026

Mostly VFR conditions ongoing and expected to continue through the TAF period, though some lower clouds will likely transition between SCT-BKN putting some MVFR CIGs in at times. There remains a chance for showers and isolated storms this afternoon into early evening. Kept with prob30 at KDSM due to lower confidence in impacts at that terminal. Moved KOTM to a TEMPO with terminal more likely to see rain, but confidence in thunder occurring within 5SM of the airport remains too low to use explicit mention, and will update as trends develop. Patchy fog will then be possible again overnight, though highest chances at this point are west of the TAF sites. Winds remain light through the period but variable at times and otherwise out of the north to east.

DMX WATCHES/WARNINGS/ADVISORIES

None.