textproduct: Des Moines

KEY MESSAGES

- Very warm today with record heat expected for some locations. Elevated fire weather possible in southern and western Iowa with relative humidity 25-30% and breezy south wind.

- Strong to severe storms possible in central to northeast Iowa with large hail the primary hazard.

- Tuesday cold front brings gusty winds with cooler temperatures the rest of the week. Precipitation chances return on Tuesday with several chances through the rest of the week.

SHORT TERM /THROUGH TONIGHT/

Issued at 256 AM CDT Mon Mar 30 2026

Quiet conditions across Iowa early this Monday morning as southerly flow continues to usher in warmer, more moist air. The surface low remains off to the west across South Dakota and Nebraska this morning with the warm front draped north of the state. This will allow temperatures to warm into the low to mid 80s across Iowa today, threatening records for several locations (see Climate section below). While dewpoints will be on the rise today, better moisture transport is into eastern Iowa. Western and central Iowa will see relative humidity this afternoon in the 25-30% range. At the same time, winds will gust 20-25+ mph through the afternoon with higher winds forecast across southern Iowa. This will allow for a period of elevated fire weather conditions in western and southern Iowa through this afternoon.

This evening the low level jet increases moisture transport into the area with convection expected to develop on the nose of the low level jet as it meets the warm front. Development is anticipated in central Iowa around 00-03z with activity moving east overnight and clearing our area by 05-07z. Expect elevated storms to develop with soundings still indicating a decent EML in place. MLCAPE exceeds 1500 J/kg with 0-6km shear of 30-40 kts and mid level lapse rates of 8 C/km, supporting large hail as the primary hazard. Winds remain a secondary hazard, especially for any storms that develop a little further north where soundings have a better dry layer through the low levels. If storms are able to develop better cold pools they would also increase the wind threat. At this time, this is a more isolated hazard.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 256 AM CDT Mon Mar 30 2026

As noted in the previous discussion, Tuesday marks the transition day for Iowa. As the low pulls east a strong cold front will pass across the state through the day. This will result in a wide range to highs on Tuesday with northern Iowa in the low 50s while southeast Iowa is able to warm into the upper 70s ahead of the front. There is a tight pressure gradient in place with the frontal passage with cold air advection and subsidence behind the boundary. This will make for a rather breezy day with gusts of 25-35+ mph indicated by mixing in model soundings. The stronger gusts are most likely across northwest Iowa. The cold front with shunt the deep moisture transport off to the southeast later in the day. Some shower activity is expected with the frontal passage on Tuesday, with better convective development is far southeast Iowa late in the day as that area has a longer window for daytime heating ahead of the front. A few stronger storms are expected in southeast Iowa, however more robust development is anticipated south and east of the area.

The pattern becomes rather messy from Tuesday night through the rest of the upcoming week with several perturbation moving through the flow. Tuesday night and Wednesday a weak low across the southwest lifts into Iowa with increasing shower activity expected across Iowa. By Thursday, upper level support arrives in the form of a deepening shortwave trough. Cold air continues to filter in on the northern edge, which may allow for a period of wet snow. Soundings continue to indicate deep saturation through the DGZ with most of the column below 0C for period in northern Iowa. Towards central Iowa the warm nose occasionally warm to 2-3C with cooling back to around 0 to -1C at the surface. The warm nose is not overly deep and the surface is not sharply cold, reducing any major icing concerns at this time. A sloppy rain/snow mix and partially melted flakes are the most likely mix in this scenario, but worth monitoring for changes to the thermal profile in this period.

A more robust wester US trough will amplified as it moves east, reaching the area by Friday into the weekend. There is plenty of time for the details to change, but for now it appears that there will be some thunderstorm/severe risk Friday. Then wrap around precipitation into Saturday that could fall into the wet flake category once again depending on the degree of cooling on the back side of this system.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 636 AM CDT Mon Mar 30 2026

VFR conditions prevail much of the TAF period. Winds today will become breezy out of the south-southwest at 20-25 kts. After 00z thunderstorms are expected to develop in central Iowa, moving east through the overnight. The expected axis of thunderstorm activity has shifted south, so only included prob30 mentions at KDSM/KALO at this time. Initial development is expected to be scattered, which precluded any prevailing mention at this time.

CLIMATE

Issued at 256 AM CDT Mon Mar 30 2026

Forecast and Record High Temperatures for Select Central Iowa Cities...

============================================= | Monday | Period | Forecast Record/ | of City | High Year | Record ============================================= Des Moines 85 83/1968 1878- Mason City 80 78/1967 1903- Ottumwa 85 83/1967 1923- Waterloo 81 84/1967 1895- =============================================

DMX WATCHES/WARNINGS/ADVISORIES

None.