220
FXUS63 KTOP 291053
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
553 AM CDT Tue Sep 29 2026

.KEY MESSAGES...

- Multiple rounds of heavy rain, beginning Tuesday PM and ending
Thursday night. Flood Watch remains in effect for parts of north-
central and northeast Kansas.

- Widespread rainfall totals of 1-3" are expected. Locally higher
amounts of around 5".

- A few stronger storms are also possible Wednesday evening towards
central KS, with gusty winds the main hazard.

&&

.DISCUSSION...
Issued at 319 AM CDT Tue Sep 29 2026

An impressive look on water vapor imagery this morning, with a deep
upper low over southern California beginning to absorb Hurricane
Polo as it makes landfall over Baja California. Broad southwesterly
flow is in place ahead of the low all the way eastward to the
Plains, allowing tropical moisture to stream northwards. Yesterday
evening`s 0z sounding here at TOP had a PWAT of 1.27" - most
guidance takes that all the way up to around 2.0" by tonight`s 0z
sounding. This will set the stage for multiple rounds of heavy rain
as the upper low approaches the Plains over the next couple days.
The first round arrives this afternoon and evening as a weaker lead
wave approaches the Plains. While most of the area should see some
rain with this first round, the most widespread rain and best
potential for local 1-3" totals by tomorrow morning should be across
north-central KS.

After perhaps a bit of a lull Wednesday morning, the focus will
remain across north-central KS for the next round of showers and
storms. Mid-level dry slot nosing in across western KS should help
an axis of instability develop across western/central KS, though the
extent of this will depend on coverage of earlier clouds and rain.
At any rate, expecting another round of convection to develop
towards central KS during the afternoon and evening. If around 1000
J/kg of CAPE can develop just west of the area, it`s not out of the
question for a few stronger storms with isolated damaging winds. The
heavy rain will remain the main hazard though. Good confidence in
some more pockets of 1-3" towards north-central KS, given deep
moisture, weak instability, and strong synoptic forcing.

Wednesday night may see another brief lull in rain coverage before
more widespread rain redevelops early Thursday. This will be as the
best mid-level height falls overspread the area with the approach of
the upper low and a cold front begins to shift southeast across the
area. In contrast with the first two rounds, which should see less
of an impact across east-central KS, this last round will see heavy
rain potential across the entire area through Thursday evening.

While the recent trends in model guidance have actually been a
slight shift back to the south, the total QPF forecast (Tuesday
through Thursday night) remains a general 1-3" across a majority of
the area. The greatest potential for local amounts to around 5"
still appears to be across north-central and northeast KS where the
Flood Watch remains in effect, as this area is most at risk for
multiple rounds of heavy rain.

Rain chances will drop off in the wake of the cold front, with just
a few leftover light showers by Friday morning. In contrast to the
highs in the 80s today and tomorrow, highs Friday through Sunday
behind the front look to stay in the 60s to low 70s. A drier airmass
and clearing skies should help overnight lows drop into the 50s.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 549 AM CDT Tue Sep 29 2026

Winds become more southerly and pick up to around 10-12
kts by mid-day. The main challenge will be timing multiple rounds of
showers, and any potential lower ceilings with them. Currently
expecting one more scattered round to move northeast over the late
afternoon to mid evening hours, followed by a second round of likely
greater coverage farther west towards KMHK overnight. Some guidance
suggests these showers will be accompanied by MVFR to IFR stratus,
but past similar setups suggest that these lower ceilings will be
more scattered, with low-end VFR ceilings generally prevailing.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flood Watch from this evening through Thursday afternoon for KSZ008-
KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-
KSZ034.

&&

$$

DISCUSSION...Reese
AVIATION...Reese