textproduct: Des Moines

KEY MESSAGES

- Slight Risk (Level 2 of 5) for severe weather in southeast Iowa today. Will watch closely for chance for nearby wind and tornado threat.

- Breezy Wednesday with fire weather concerns.

- Next windows for precipitation late Thursday and again over the weekend.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 334 AM CDT Tue Mar 10 2026

Troughing to the southwest continued to advect in the EML overnight, setting up midlevel instability for storms later today, seen best in low level water vapor satellite imagery. A surface low was analyzed over northwest Kansas. This low will get picked up by the inbound northern stream wave and advected northeast. Meanwhile, the LLJ is open into the Plains, but veers to the east as it nears Iowa. Low level moisture will be a challenge for precipitation in the next 24- 36 hours. Another surge of low-level moisture will come as the surface low grazes southern Iowa today. Enough theta-e advection may allow for cap erosion by midday today, which would translate to elevated thunderstorms with hail over southern and southeast Iowa. Straight hodographs with effective shear of around 40kts will allow elevated storms to last longer. The warm sector with 60 degree dew points is close by, residing in far southeast Iowa late this afternoon. Will need to monitor frontal placement for places like Davis county this afternoon as initiation of surface-based convection is progged to start near the warm front between 4 and 7pm. All hazards will be possible in the warm sector, with most of this activity contained to our south and east. Snow amounts on the back side of this exiting system continue to remain low (under 1"), owed to the lack of low-level moisture and delay in freezing temperatures until early Wednesday. Wind gusts as they sit on Wednesday may be underdone. Soundings suggest the average PBL winds are close to 30kts and strong subsidence and dry air give high confidence that these winds will transfer down.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 334 AM CDT Tue Mar 10 2026

Troughing ensues over the Great Lakes region for the remainder of the week, effectively locking Iowa into northwest flow for the remainder of the period. There will be a temperature gradient across the state as the thermal ridge gets pulled into the state from passing waves. The main windows of precipitation come in late Thursday and again late Saturday and Sunday. The second system brings chances for snow.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1239 PM CDT Tue Mar 10 2026

A lot of moving parts this aviation period. Starting with right now, a stubborn area of IFR to LIFR stratus has lingered over southern Iowa, impacting KOTM through much of the morning. Fog beneath this stratus should continue to dissipate as heating continues and winds pick up, but confidence is low on how quickly this will be. This area of stratus will continue to drift northward which should bring drier conditions and improvement into the KOTM area. As this drifts north, stratus will start to move into the KDSM bringing MVFR conditions to KDSM. Have not included IFR conditions in KDSM TAF, but depending how aggressive stratus progression is, IFR ceilings may develop for a period of time this afternoon. Will be monitoring this stratus deck closely and amend accordingly.

In addition to stratus, showers and thunderstorms develop this afternoon and evening in southeastern Iowa, potentially impacting KOTM. However, trends for rain and storms have been moving farther south which could keep KOTM mostly dry late this afternoon/evening. Have maintained thunder and rain mention for now, as storms are still possible in proximity, but will likely need to amend as location becomes clearer. In addition to initial development late this afternoon, rain may also extend northward into southern Iowa overnight, impacting KOTM for a period of time after midnight.

Finally, a light rain transitioning to light snow will drift through northern into north central Iowa, impacting KFOD, KMCW and KALO early Wednesday morning. Expectation is for this to be fairly light, but could occur for a few hours at each site. This will also bring MVFR to IFR conditions as well. Southern extent of this precipitation at KDSM and KOTM is less certain due to drier conditions farther south. However, if any precipitation does occur farther south Wednesday morning, it would likely fall as rain rather than snow.

DMX WATCHES/WARNINGS/ADVISORIES

None.