textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Warm and dry conditions expected Monday and Tuesday.

- Several rounds of showers and storms are likely (60-80% chance) across the forecast area mid/late week. Heavy rainfall is possible, especially Wednesday night into Thursday.

DISCUSSION

Issued at 326 AM CDT Mon Sep 28 2026

Surface and upper-air observations from 00Z show subtle changes to the overall synoptic pattern over the last 12-24 hours. Over New England, the upper trough has caught up to the closed low/Nor'Easter embedded within the broader upper-level ridge. This system will gradually be reabsorbed and carried northeast back to the Atlantic over the coming days. Meanwhile, the upper trough across the western CONUS is set to continue amplifying. As it does so, the base of the trough is expected extend flush against the southern U.S. border, closing itself off from the ~130 kt jet streak protruding into British Columbia. Between now and Tuesday, conditions look rather quiet as the axis of the ridge leading the western trough builds into the region. Some patchy fog may be able to develop across northern Missouri during the early morning hours on Monday where winds are light and cloud cover is minimized. Warmer conditions are expected across the region both Monday and Tuesday, with high temperatures in the mid/upper 70s along and north of the US-36 corridor. Further south, maximum temperatures are more likely to settle in the upper 70s and low 80s.

The dry weather will not last long, however, with rain chances returning as soon as late Tuesday evening. Latest guidance suggests that the remnants of weakening Hurricane Polo are to lift toward the southern New Mexico/Texas border on Tuesday, by which point residual tropical moisture and vorticity would be ingested into the aforementioned cyclone. This system is then progged to surge northeastward into portions of the Southern and Central Plains, introducing heavy rainfall and flooding concerns. Tuesday night into early Wednesday, showers and thunderstorms are expected to enshroud much of the Plains as the low level jet intensifies in the vicinity of the extremely moist airmass. Showers and storms will be most likely across the northwestern and western portions of the forecast Tuesday night, gradually expanding in coverage throughout the day on Wednesday. As things stand now, all portions of the forecast area have >80% PoPs sometime between Tuesday and Thursday night; for most, the increased likelihood of rainfall arrives late Wednesday night into Thursday when PWATs between 1.8 and 2.1 nose into the area. For context, these values sit roughly around the 99th percentile compared to both the NAEFS and GEFS climatologies.

While confidence in rain is high, confidence in total rainfall accumulations is certainly less so. Looking back at LREF probabilities from the middle of last week up through the most recent run, there is a clear downward trend in total expected QPF. However, this alone fails to tell the whole story; instead, high uncertainty is confirmed by ensemble spreads. For total rainfall accumulations by Friday evening, there is a 1.5 inch spread between the 25th and 75th percentiles across the forecast area. For the 10th and 90th percentiles, spread spikes to about 3.5 inches. Needless to say, there are substantial challenges in skillfully assigning total accumulations at this time. This is compounded by unclear frontal boundary placements which are pivotal in determining key areas to hone in on for flooding potential. Despite the level of uncertainty remaining, widespread accumulations of 1.5" to 2" seem to be the most likely solution at this junction. That said, it will be key to follow system evolution and model trends over the coming days as this will guide future updates.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 612 AM CDT Mon Sep 28 2026

Prevailing VFR conditions through the forecast period. As the morning progresses, expect CIGs to gradually rise and give way to SCT high clouds later this afternoon and evening with light easterly winds.

EAX WATCHES/WARNINGS/ADVISORIES

MO...None. KS...None.