textproduct: Des Moines

KEY MESSAGES

- Quiet tonight, then increasing shower and occasional thunderstorm chances on Saturday morning. More scattered shower and isolated thunderstorm chances continue through the evening and overnight.

- Additional shower and thunderstorm chances over the area on Sunday. A few storms could be severe, especially in the afternoon hours.

- Active weather continues through early next week, with periods of thunderstorms possible, with potential for severe weather and additional rises on area rivers.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 256 PM CDT Fri Apr 10 2026

The boundaries responsible for yesterday's rainfall have pushed well south of the area today, leaving Iowa under broad surface high pressure and generally dry conditions. Skies have been mostly clear over the state, aside from some lingering cumulus in southeastern Iowa and a few mid-level clouds drifting into far southwestern Iowa. These mid-level clouds have been associated with some light rain/sprinkles over western Iowa into Nebraska, but are generally unimpactful.

Our dry conditions will continue into the evening and early morning hours, but increasing clouds will arrive by daybreak tomorrow as return flow behind the departing high brings gulf moisture back up into the state. This push of theta-e advection will also bring scattered showers and occasional thunder through the state on Sunday, leading to yet another rainy day in April. However, despite the healthy surge of moisture, recent high resolution guidance has been indicating an intrusion of dry, mid-level air that is leading to a lull in precipitation chances through the afternoon and evening. In addition to the dry air, an overall lack of any prominent forcing mechanisms beyond the initial push of theta-e advection has led to a decrease in modeled precipitation and amounts through late Saturday afternoon and early evening. That said, the unseasonably high moisture transport with PWATs of 1.2"+, persistent warm air advection, and a strong 50 to 60 kt low level jet could very well outperform what the models are currently simulating for precipitation Saturday afternoon and evening. Therefore, have maintained rain and isolated thunderstorm chances throughout Saturday and Saturday night, despite this drier trend in short range guidance. For much of the area, instability will be rather marginal, (under 500 J/kg) but a push of higher most unstable CAPE values (1000+ J/kg) into southwestern and western Iowa on Saturday afternoon and evening could introduce the potential for a few stronger storms, especially as the LLJ oscillates into western Iowa. The storm prediction center has expanded their marginal risk for severe weather into Iowa, citing similar concerns about the strong LLJ and moisture content into Saturday night. Storms will likely be elevated thanks to a mid-level warm nose, making hail the primary concern should any stronger storms develop.

This pattern of warm, moist, southwesterly flow generally persists through the day on Sunday. Like Saturday, lack of any prominent forcing mechanism beyond the low level jet and broad warm air advection makes it difficult to lock down exact timing and evolution of showers and thunderstorms during the day on Sunday, but generally expecting scattered activity to continue in Iowa on Sunday. The jet will be oscillating eastward through the day which will be the trend of any activity during the day as well. One notable change on Sunday, however, will be increasing surface and low level temperatures and dewpoints, which will therefore boost instability values up during the day. This destabilization will provide a bit more thermodynamic support to any parcels that can be displaced within the moist environment. Of course, temperatures and destabilization will depend on how much convection/rain occurs during the day, making the potential for severe weather somewhat conditional on atmospheric recovery. Long-range guidance manages to produce 1000 to 2000 J/kg of most unstable CAPE, some of which becomes surface based by late afternoon. Kinematics look somewhat marginal with fairly unidirectional flow and only around 30 kts of shear, but this would likely be sufficient for at least a few organized updrafts. Therefore, severe thunderstorms are certainly a potential on Sunday, albeit conditional depending on destabilization. Specific details for Sunday's hazards should become clearer as high resolution guidance begins to capture it in the coming days. Intermittent rain through the weekend will also continue to decrease storage in area rivers, for more details on hydrological concerns, see the hydro section below.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 256 PM CDT Fri Apr 10 2026

Our active weather pattern continues through early next week, with multiple days of rain and thunderstorm chances, some of which may be severe. The southwest flow pattern continues to make it difficult to pin down exact timing windows and progression through next week, as much of the activity will be tied to weak shortwaves ejecting through the overall pattern. Each days chances will also be contingent on how previous days' activity evolves. Therefore, the forecast at this range is strongly tied to the environment that will be in place next week, as surface low pressure remains to our west and warm, moist southerly flow continues over the state. This will allow for ample amounts of instability overhead through Monday and Tuesday, and potential for thunderstorms through that same period. With this constant stream of warm, moist flow surface dewpoints will remain in the 60s, which will both boost severe weather potential and just overall temperatures through the week. Highs look to be quite warm in the 80s Monday and Tuesday, with overnight lows only falling into the 60s (again, thanks to the warm dewpoints). This persistent pattern locked in overhead eventually comes to an end late Tuesday into Wednesday as the longwave trough over the western CONUS releases eastward. Depending on timing of the wave's passage, more severe weather chances may develop Wednesday, but current forecast looks to keep this mostly to our south and east. The storm prediction center has been hitting next week hard with Day 4-7 15% severe weather outlooks, again trying to communicate the potential the environment has for severe weather next week. The signal should continue to clear up as we get through the weekend, so stay tuned to the forecast through the weekend.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 640 PM CDT Fri Apr 10 2026

VFR conditions are expected to remain tonight and into early Saturday morning. Clouds however will increase through the morning from southwest to northeast, with low ceilings expected to cover the state by 15-18z, leading to MVFR/IFR conditions. Area of rain showers will accompany this increase in clouds, with the highest chances (50-80%) after 12z. There is a remaining potential for thunderstorms with this activity late morning and into the afternoon, though confidence remains low at this time, and will continue to closely monitor for changes. Winds increase out of the southeast through Saturday, with gusts up to 20-25 knots expected.

HYDROLOGY

Issued at 256 PM CDT Fri Apr 10 2026

Last night's rainfall led to renewed rises on several rivers and streams mainly between US 30 and IA 92. Those rises will route downstream from that region, leading to later rises downstream.

Attention then turns to potential impacts from additional rainfall this weekend and into next week. Although QPF location and timing remains uncertain and will drive where any potential high water sets up, the overall signal is that renewed or additional moderate or significant within-bank rises are likely across the eastern half of the state especially the eastern third, with some isolated to scattered minor river flooding and a couple locations possibly seeing moderate river flooding. Those with sensitivities to river flooding will want to stay on top of the forecast through at least the first half of next week.

DMX WATCHES/WARNINGS/ADVISORIES

None.