textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Isolated to scattered showers again today, mainly for areas south/east of I-35. A few thunderstorms are possible as well, but severe weather is not expected.

- The potential for heavy rain and flooding for the middle of the week is increasing. Multiple rounds of heavy rain are expected in the region from Tuesday night through Thursday.

DISCUSSION

Issued at 221 AM CDT Sun Sep 27 2026

Water vapor imagery shows a shortwave trough over northern Missouri, slowly moving eastward. It's progress is being hampered by the the deep upper low/ Nor'Easter over the eastern US that is stuck within a broad upper ridge. This is close to a Rex block setup but not quite there just yet and it seems unlikely to evolve into a true blocking pattern. Regardless, it is still slowing the progression of waves through the middle of the country. There is another wave, potentially a subtle internal PV anomaly, leading to showers and storms in southeastern Kansas as of 07Z. with the near blocking pattern to the east, this wave will meander over/through the southern half of the forecast area today, leading to continued isolated to scattered showers and thunderstorms, mainly south/ east of I-35. While we'll see greater instability, especially across eastern Kansas and far western Missouri, shear remains weak so severe weather is not anticipated. Precipitation chances should finally start to wind down by 03Z to 06Z Monday, leading to dry conditions for Monday into Tuesday.

Focus then turns to the potential for widespread heavy rainfall and flooding for the middle to later portions of the work week, Tuesday night through mainly Thursday. From a synoptic perspective, this pattern flashes heavy rainfall. In the upper- levels, a potent shortwave trough will be moving into the Southwest. This will help draw copious amounts of mid and upper- level moisture from the Pacific into the central US. This moisture is will be the remnants of what is currently Hurricane Polo. In the lower-levels, a broad high pressure area over the eastern US will lead to a strong moisture transport from the Gulf northward into eastern Kansas and western Missouri. This combination of rich lower-to-mid-level moisture and upper-level moisture will lead to very anomalous precipitable water values. In fact, these values are 3+ standard deviations above normal for this time of year, above the 99.5 percentile for a large portion of the area, and at the max values on the NAEFS percentiles and GEFS M-climate. Ensemble guidance shows roughly a 10-20% chance for at least four inches of rain for the run ending at 7PM Friday. This jumps to 20-30%+ for total rain of at least 3 inches through the same time frame. With all that said, there remains a fair amount of uncertainty on where the heaviest rains will actually setup. That will largely depend on where the strongest forcing sets up as the shortwave ejects into the Plains Wednesday into Thursday as the system takes on distinctive mid-lattitude cyclone characteristics, with a notable deformation area, a warm frontal region extending eastward, and cold front extending southward. Each of these areas will provide a focus for heavy rainfall and placement of these features will be key to defining the areas with the greatest flooding potential.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 628 AM CDT Sun Sep 27 2026

VFR conditions currently may trend to MVFR (20-40% chance) with ceilings around 1500 ft. There is some potential (15-20%) for IFR ceilings as well from later this morning through the afternoon. These conditions are more likely across northeastern KS into northwestern MO and adjacent areas of NE and IA, with lower probabilities further south and east. While confidence isn't particularly high on these conditions occurring, with chances less than 50% for the terminals, have maintained the mention in the forecast. Based on HREF probabilities, conditions likely trend to VFR by 06Z to 09Z tomorrow morning. Winds will be light through the forecast with winds generally from the east to southeast.

EAX WATCHES/WARNINGS/ADVISORIES

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