textproduct: Des Moines

KEY MESSAGES

- Near record to record warmth persists into Monday.

- Low chances for precipitation far south Monday night. Greater chances central and south late Tuesday/Tuesday night. A strong storm may occur.

- Greater chances for widespread precipitation Wednesday night and Thursday.

- Much cooler end of the week and into next weekend.

SHORT TERM /THROUGH TUESDAY/

Issued at 347 AM CDT Mon Oct 12 2026

The latest surface analysis shows the approach of a weak, mostly dry cold front currently positioned over northwestern Iowa. Ahead of the boundary, warm-sector temperatures are sitting in the upper-60s to lower-70s. Behind the front, under cold air advection, temperatures drop into the upper-50s to lower-60s. Within the warm sector, two surface high-pressure centers exist: one centered over the Four Corners region and the other over the Sand Mountains of northern Alabama. Both features are aiding in keeping the area dry overnight.

Through the remainder of the overnight period and into the day today, the cold front will continue diving through the forecast area. Some saturation ahead of the boundary appears likely, but this will primarily manifest as high level cloud cover. Large-scale vertical motion remains weak, resulting in negligible PoPs for the local forecast area, while stronger forcing and higher PoPs reside closer to the surface low center in Minnesota. Outside of precipitation chances, high temperatures ahead of the front will remain above average, climbing into the mid-80s.

Behind Mondays front, surface high pressure builds back into the region. However, as a shortwave trough breaks off the quasi- stationary upper-level trough over the Rockies on Tuesday, chances for showers and storms will increase as lee-side cyclogenesis takes place. This setup positions the area on the cool, northern side of a low-level theta-e gradient. Along this thermal and moisture boundary, isolated to scattered chances (20-40%) of showers and storms are expected. Post-frontal air will keep conditions cooler, with high temperatures falling about 10 to 15 degrees below Mondays values.

A weak, mostly dry cold front will move through the region on Monday, bringing some cloud cover and warm highs in the mid-80s, while stronger forcing and precipitation remain further north. Cooler high pressure builds in behind the front for Tuesday, dropping temperatures by 10 to 15 degrees. Isolated to scattered showers and storms are possible Tuesday.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 217 PM CDT Sun Oct 11 2026

The shallow surface boundary will stall somewhere across northern Missouri on Tuesday and favor the more northern solutions for this boundary location given the west/southwest flow aloft and how shallow the feature is. Moisture will overrun this boundary and will bring increasing chances for showers and storms to parts of central and southern Iowa. MUCAPE values may approach 1000 J/kg over far southern Iowa. This does look possible and should saturation occur near 800-850 mb, lapse rate above this level are sufficient for this MUCAPEs and could support marginally large hail. The greater chance for showers and storms arrive Wednesday night into Thursday as the main upper low lifts northeast into the region. A strong system diving south out of Canada will quickly push the precipitation out of the area. Much cooler temperatures will follow with highs in the 50s and 60s and overnight lows in the 30s along with the potential for frost perhaps as early as Friday night.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1035 PM CDT Sun Oct 11 2026

LLWS conditions are expected to persist for all TAF sites through the night and end once daytime heating commences. Southerly wind gusts of 15-20 kts will return this afternoon and gradually veer to the southwest/west through the evening as a cold front moves into the area. VFR conditions prevail through the forecast period.

DMX WATCHES/WARNINGS/ADVISORIES

None.