textproduct: Des Moines

KEY MESSAGES

- Thunderstorms possible mainly south Tuesday/Tuesday night. A few severe storms may occur over far southern Iowa with hail the primary threat.

- Cooler but generally above seasonal normals for temperatures mid to late week.

- Perhaps more wintry weather late this weekend and into early next week.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 246 PM CDT Mon Mar 9 2026

Surface boundary has been slowly settling south across Iowa today and is beginning to slow as the boundary is becoming nearly parallel to the westerly flow aloft. Despite a 20 degree temperature spread from south to north across the area, the atmosphere remains very dry and has resulted to few to no clouds passing over the state. For tonight, the boundary will settle into southern Iowa and stall. Des Moines, Waterloo, Mason City and Ottumwa low temperatures this morning are currently at Record warm low temperatures for each site. The current diurnal cooling and projected 06z temperatures suggests that a few or all of the potential records may stand for today.

The low level moisture is not too far away though with dew points in the low 60s over central and southern Missouri. That moisture will begin a slow surge northward on Tuesday as the upper level low, which is now near the west coast of Baja California, begins to move east towards west Texas. This will cause the low level surface dynamics to amplify and allow for a stronger moisture surge northward. An elevated mixed layer (EML) is expected to develop on Tuesday and create a surface instability capping inversion over southern Iowa and in vicinity of the surface boundary. It is possible, some elevated convection does initiate late morning into early afternoon as a surge of strong theta-e advection lifts northward over southeast Iowa resulting in 2000+ J/kg mucape. The uncertainty is if there will be enough saturation and vertical ascent from the saturated point for convection to be initiated. If this does occur, then a few elevated hail storms could occur. Otherwise the next potential arrives late Tuesday evening and after midnight across the far south. Again, this looks mainly to be a hail threat though that will become limited as stronger saturation occurs and limits the instability and weakens lapse rates.

High temperatures Tuesday will depend on stratus development. With increasing dew points under the EML/inversion aloft, stratus could occur and would limit high temperatures.

A brief period of wintry precipitation is possible over far northern Iowa Tuesday night also. At this time, expecting only minimal snow accumulations and minimal impacts with this precipitation with the period of saturation short.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 246 PM CDT Mon Mar 9 2026

Generally quiet and cooler weather on Wednesday with high pressure ridge moving across the region. Temperatures will be above seasonal values Thursday through Saturday with highs mainly in the 40s and 50s. A strong short wave will pass move into the region on Sunday and will create a long wave trough for early next week. This system may bring light snow back to Iowa along with cooler temperatures.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1230 PM CDT Mon Mar 9 2026

A boundary is moving slowly south across Iowa this afternoon and is expected to stall over central Iowa. The boundary will bring erratic wind direction to KDSM/KALO at times this afternoon. Still monitoring the potential for MVFR or lower stratus on Tuesday morning. At this time, the greatest potential is at KOTM but all sites may be impacted prior to 18z Tue.

DMX WATCHES/WARNINGS/ADVISORIES

None.