textproduct: Topeka

KEY MESSAGES

- Remnant tropical moisture leads to instances of heavy rainfall and flooding Tuesday evening through Thursday. A Flood Watch has been issued across portions of northeast and north central Kansas.

- Seasonable temperatures with highs in the upper 70s to low 80s transition to cloudy skies and rain-cooled temperatures by late week with highs in the 60s to low 70s.

DISCUSSION

Issued at 205 PM CDT Mon Sep 28 2026

Upper ridge axis is observed from the southern plains stretching into the Midwest this afternoon. Meanwhile the closed upper low is rotating through CA while upstream moisture is increasing into the CO Rockies and southwest CONUS. Hurricane Polo remains off the Baja California coastline, anticipated to weaken as it amplifies the moisture transport into New Mexico and eventually the Plains on Tuesday. For this evening, stratus deck gradually fills back in overnight similar to this morning's setup with lows in the lower 60s. Fog is not expected to be a concern as sfc south winds increase by sunrise from 10 to 20 mph sustained. Initial rain chances begin Tuesday late afternoon and evening towards north central Kansas as southwest flow aloft deepens ahead of a slow-moving cold front. A strong low level jet and ample moisture transport persists into Wednesday and Thursday where PWAT values climb to near 2 inches, representing greater than 99th percentile on the NAEFS and EC ensembles. The combination of the low level frontogenesis with deep warm cloud layer depths and strong moisture transport are increasing confidence in flooding concerns. In addition, MUCAPE increases to near 1500 J/KG, introducing chances for thunderstorms in north central KS and therefore higher rainfall rates. Forecast rainfall amounts are generally 1 to 3 inches area wide with locally higher amounts of 4 to 5 inches north of I-70. This is where a Flood Watch has been hoisted from Tuesday evening through Thursday.

While most convection holds below severe limits, there could be a few severe storms Wednesday afternoon and evening as the sfc trough enters the state amid a dryline positioned north to south in western Kansas. Location of the sfc low and degree of forcing within the warm sector of eastern Kansas varies among guidance, lending to low confidence in location and threats for severe weather Wednesday.

The main upper trough ejects northeast into the Upper Midwest by Thursday night, pushing the cold front through the state. Dry conditions return Friday into the weekend as surface high develops throughout the central conus. Highs Friday through Sunday average in the upper 60s, as clearing skies bring overnight lows down into the lower 40s.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 638 PM CDT Mon Sep 28 2026

This evening, low level cigs may scatter slightly over KMHK but remain VFR overnight. Near sunrise expect steadily increasing cloud coverage from west to east with lower bases into the morning. Winds increase into sunrise, so LLWS looks marginal at this time and would likely be strongest around KMHK terminal before winds begin to mix to the surface with gusts increasing for the balance of the morning through much of the afternoon period. Uncertainty remains for onset timing for precipitation. But with dry air in the column would expect saturation to be a gradual process tomorrow with the end of the period possibly seeing the first showers and possible TS.

TOP WATCHES/WARNINGS/ADVISORIES

Flood Watch from Tuesday evening through Thursday afternoon for KSZ008-KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023- KSZ024-KSZ034.