textproduct: Des Moines

KEY MESSAGES

- Severe thunderstorms are expected to continue at times in central to eastern Iowa this afternoon. All severe hazards are possible.

- Severe storms Friday afternoon and evening in southern half of Iowa with a Enhanced Risk (level 3 of 5) for severe storms. All severe hazards are possible.

- Cooler and quite this weekend, could become active again later next week.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 247 PM CDT Thu Apr 2 2026

While light rain showers are present over portions of eastern and northeastern Iowa this afternoon, the main focus area of concern today is at the center of the low pressure system, which as of 1pm is located right over northwest Missouri into southwest Iowa. In this area, the warm front is oriented west to east from Creston through Oskaloosa, while the cold front is oriented just over southwestern Iowa from Atlantic down through Clarinda. Showers and thunderstorms have recently developed in this area of interest as the dry slot moves in and areas of clearing have been noted. A few storms just north of the IA/MO border have grown upscale in strength, where Severe Thunderstorm Warnings were recently issued for potential damaging winds and hail. The expectation for the rest of the afternoon is for additional storm development to occur over southern into south central Iowa in the warm sector, racing northeastward across the area over the next 4-5 hours. The near storm environment continues to show increasing instability values around 1000 J/kg and shear values around 40-45+ knots into the state later this afternoon, which will lead to a more favorable environment for strong to severe storms. Lapse rates around 7 C/km and general unidirectional shear is indicated, which could lead to hail production and damaging wind gusts, though marginal in nature. Curving hodographs are indicated given some directional shear over the triple point, with helicity values around 200 m2/s2, which leads to the continued potential for a few tornadoes into this evening. A Tornado Watch has been issued for over much of southern and eastern Iowa until 8pm. Storms are expected to exit the region into the evening, though remaining over far eastern Iowa. Cold air will surge in tonight into Friday behind the departing system, with overnight lows expected to fall into the 30s to low 40s.

After a brief period of quieter conditions Friday morning, another mid-level trough and deepening surface low to the east of the Rockies is still expected to pivot up into southwestern Iowa by the early afternoon, bringing the next potential for showers and storms into Iowa. The expectation remains for this system to lift northeast across the state through the afternoon to evening, with the triple point directly overhead Central Iowa around the early evening. CAM guidance indicates that two rounds of activity are expected to occur: The first wave being north of the warm front lifting across western to northern Iowa from about mid to late morning, and the second just ahead of the west to east tracking cold front, which looks to enter western Iowa around 2-3 pm and track eastward over the forecast area through about 9-10pm, before moving out of the area.

Regarding the initial wave through the morning, particularly over western into northwest Iowa as CAM guidance shows this round of convection developing, the parameter space from soundings in these areas shows instability values of 500-1000 J/kg, alongside shear values of 30-35 knots, while steep lapse rates up to 8 C/km and directional shear are also indicated. Further analysis shows a warm layer in the low levels that would allow for storms to be elevated in nature, with the main hazard of concern with any storms likely being large hail. As mentioned above, additional storms are expected to develop ahead of the cold front later Friday afternoon and remaining through the evening, where the environment in the warm sector features instability values around 2000 J/kg, bulk shear of 40-50 knots, and temperatures rise into the 60s to low 70s over the southern half of Iowa paired with dewpoint values increasing into the 50s to low 60s. Helicity values in the low level upwards of 300- 400 m2/s2 and stronger directional shear indicate a higher tornado threat mainly south of I-80, where the Enhanced Risk per SPC remains. Damaging winds and large hail are also possible given the expected parameter space. Please make sure to have multiple ways to receive warnings through Friday, and have a plan in place to shelter in areas where warning are issued.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 247 PM CDT Thu Apr 2 2026

Drying will continue across the state overnight into Saturday, with increasing northwesterly flow and cold air advection behind the departing system to the northeast that will lead to cooler conditions for the day. Highs by the afternoon are expected to reach into the 40s to low 50s, along with breezy conditions, especially over northwestern Iowa with gusts up to 35-40 mph. Wrap around rain/snow continues is possible mainly over far northern Iowa, though overall impacts, if any, should be minimal at this time and will continue to be monitored. Surface high pressure descends across the Dakotas into the region Saturday night into Sunday, with midlevel ridging expected to build through early next week and cooler air remaining overhead as highs generally remain in the 50s through at least Tuesday.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 637 PM CDT Thu Apr 2 2026

Low clouds will blanket the area tonight, producing IFR ceilings initially but then improving to MVFR before midnight. It is possible DSM or OTM may clear out overnight, after 06Z, but more likely the ceilings will persist. Fog may also develop overnight toward sunrise Friday, and would generally remain around 3-6SM but in any areas where skies do clear, then the fog could be more dense with visibility falling to 1SM or lower. During the day Friday MVFR ceilings will prevail in most areas, and showers and thunderstorms will gradually spread back in, which is included with PROB30 groups for now.

DMX WATCHES/WARNINGS/ADVISORIES

None.