309
FXUS63 KTOP 281906
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
206 PM CDT Mon Sep 28 2026

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

&&

$$

DISCUSSION...Prieto
AVIATION...Jones