textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Warmer and dry conditions expected through Tuesday for most.

- Several rounds of showers and storms are expected (>95% chance for accumulating rainfall) across the forecast area Tuesday night through Thursday night. Heavy rainfall and flooding will be possible.

DISCUSSION

Issued at 221 PM CDT Mon Sep 28 2026

A quiet day has prevailed across the area thanks to the influences of building mid-level ridging and lingering surface high pressure. With the 850mb thermal ridge remaining displaced just to the west, temperatures should largely be similar / within a couple degrees of yesterday in most cases. The greatest exception likely being NE areas of the CWA and state where temps today will be more on the order of 10 degrees warmer, but pleasant in the lwo-mid 70s, as sunshine prevails in place of the fully overcast day Sunday.

The quiet / dry conditions will be pretty short lived though as the well advertised shift to wet conditions takes place through the rest of the week. The large scale synoptic pattern remains well corroborated among the deterministic globals and their ensembles. This being nor'easter remnants being ushered eastward, western CONUS trough/cut-off low digging into SW US, and remnants of Hurricane Polo beginning to lift northward across Baja California early this week. With the building and eastward shifting mid-level ridging over the central CONUS, deep Gulf moisture too will begin to stream northward. All of which will prime the wider region for widespread showers and storms and the potential for both river and areal flooding. This is further reflected via deterministic PWats of >2.00 inches, which would be near or at record levels for this time of the year, based on TOP sounding climatology and at 99th percentile or MAX within GEFS/Euro Ensemble SA Tables by later Tuesday onward. On the rainfall efficiency front, the deep influx of moisture unsurprisingly aids in pushing warm cloud layer depths towards 4km, hinting at potential for efficient rainfall via tropical/warm cloud processes. Some limitation on rainfall rates though with likely weaker instability due to the abundantly ongoing moist profiles, which may shift the flooding potential away from typical warm season flash flooding and toward slower onset areal and river flooding. Anyways...

Initial precipitation chances move into the NW CWA later Tuesday as a surface to low level boundary drifts southward out of the Northern Plains. Nocturnal LLJ enhances chances through the over night, and the boundary is expected to hang up over the Nebraska/Iowa areas through Wednesday as cyclogenesis over the Southern High Plains increases low level flow. This places the greatest initial heavy rain and flood potential toward far NE Kansas and NW Missouri and up through large portions of eastern Nebraska and western to central Iowa through Wednesday. The NW CWA may just miss out on the heaviest rainfall axis, and this uncertainty is reflected in 48hr NBM 25th/75th ranges of around 1.2 to 3.5 inches through Wednesday night. And keep in mind, NBM will not capture the potential/likely embedded higher amounts. Given the potential, have coordinated an initial Flood Watch for said areas with northern neighbors, beginning Tuesday night and through Thursday night.

As the synoptic pattern evolves through mid-week, western trough/Polo remnants lifting into the Plains, heavy rain location begins to shift as well; along and ahead of the developing surface cold front and further north along the deformation axis by Wednesday night and Thursday. This transition is interesting in that it "may" result in portions of the area, including the Kansas Cit Metro, being gaped or surrounded by the heavier rainfall amounts. Of course, this too remains a couple/few days out and subtle shifts in tracks too will shift the heavy rain axis locations. Regardless, it will rain area wide. Just the nuance of where the heavy rain risks shift to after Wednesday. The 24hr NBM 25th/75th ranges are unsurprisingly wide (in amount and over a very wide area), from around 0.70 to 3.00 inches. Same NBM caveat as above. Generally anticipate some expansion to the Flood Watch location over the next couple forecast cycles as details continue to come into increasing focus. Best odds may be over northern areas, where deformation area may linger and soil moistures are most saturated over the area.

Area looks to dry out later Friday and into the weekend, but both deterministic and ensemble guidance hint at some low-end opportunities for precipitation to linger over central Missouri before more substantial drying (cold front) drops in from the north Sunday.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1224 PM CDT Mon Sep 28 2026

VFR will prevail through the forecast period, with generally mid/high sct clouds across the region. Winds are currently light and east/southeasterly, but expect a southerly shift Tuesday morning.

EAX WATCHES/WARNINGS/ADVISORIES

MO...Flood Watch from late Tuesday night through late Thursday night for MOZ001>005-011-012. KS...Flood Watch from late Tuesday night through late Thursday night for KSZ102.