textproduct: Topeka

KEY MESSAGES

- Rounds of rain are expected Tuesday evening through Thursday with the heaviest rain likely late Wednesday into Thursday.

- Widespread rainfall totals of 1-2.5" are expected. Locally higher amounts of 4-5" could lead to flooding, particularly towards north- central KS.

- While a lesser hazard compared to the heavy rain risk, a few strong storms could also occur, particularly towards central KS Wed. evening.

DISCUSSION

Issued at 341 AM CDT Mon Sep 28 2026

Water vapor imagery this morning depicts a deep upper low dropping southeast across California. This is beginning to lift Category 3 Hurricane Polo northeast towards Baja California, where it will quickly weaken as it passes over the northern Mexico mountains and is absorbed into the upper low. Here across the Plains, upper ridging is now centered overhead, leading to a quieter look to the radar compared to the past few days. Low-level easterly flow is keeping some moisture and low clouds around, so can't completely rule out a brief sprinkle this morning. But these low clouds should lift north and begin to scatter out by the afternoon, allowing temperatures to warm to near 80.

Low-level winds will turn southerly by Tuesday as the upper low slowly moves east across the Southwest. Deep moisture will quickly advect north as a response. A lead impulse moving east onto the Plains could lead to rain chances beginning by Tuesday evening across central Kansas, but most of the area should stay dry through the daylight hours Tuesday. Temperatures look to climb into the 80s, especially across eastern KS where cloud cover stays thinner. Tuesday night into Wednesday night, rain chances increase further as low pressure associated with the remnants of Polo lift northeast onto the High Plains. The track of this low still looks to stay mostly to our west, along with the heaviest rainfall amounts, but more rain still appears likely across the western half of the forecast area. The best heavy rain chances area-wide still look to be Wednesday evening into Thursday evening. This will be as the upper low approaches Kansas and its moisture interacts with a cold front pushing southeast across the area. Still some differences with when this front will fully pass through the area, but most model guidance drops off rain chances by early Friday as as cooler and drier air filters in.

Turning to actual impacts, not a lot of change with this forecast package with regards to total rainfall amounts. Still expecting widespread amounts of 1-2.5", with a few locally higher totals of 3- 5". Given current hydrologic conditions, 1-3" of rain should be manageable, and wouldn't result in much notable flooding. The main flooding risk will tied to wherever those locally higher amounts fall, especially if 3-4" can fall in a short 6 hour period. Rainfall rates and flash flooding potential will likely be highest along the boundary Wednesday PM into Thursday evening, as instability strengthens some towards north-central KS with the approach of the upper low. On a related note, can't rule out some stronger storms during this period as wind shear also increases. But the heavy rain should still be the main hazard.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1153 AM CDT Mon Sep 28 2026

VFR at all TAF sites through the TAF period with slowly clearing sky from east to west today. Easterly wind will become southerly by tomorrow morning and generally 10 knots or less through the period.

TOP WATCHES/WARNINGS/ADVISORIES

None.