284
FXUS63 KTOP 011131
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
631 AM CDT Mon Sep 1 2025

.KEY MESSAGES...

- Scattered to areas (30-70%) of rain expected through the day today
and into early Tuesday. Flooding threat is low, but locally heavy
rainfall could lead to some rises in streams.

- Cooler temperatures persist over this week as another cold front
slides across the area Wednesday.

- Some storms could develop along the cold front Wednesday
  afternoon with some possibly strong.

&&

.DISCUSSION...
Issued at 359 AM CDT Mon Sep 1 2025

Mid-level water vapor this morning shows the slow moving wave that
has remained near-stationary over southeastern Nebraska and is the
main culprit for the rainy weather over the past few days. Outside
this feature, ridging builds across the southwestern US with a
deepening low over the PNW and broad troughing in the eastern US.
Today, the aforementioned wave over eastern Nebraska will begin to
push further south into northeastern and central Kansas creating
another day of scattered to areas of rain showers. Cannot rule out
an isolated rumble or thunder with the deeper convection given 500-
1000 J/kg of MUCAPE, but most precipitation should be in the form of
showers as ML lapse rates remain weak. Recent runs and trends from
RAP and HRRR analysis show a lobe of vorticity advecting a bit south
and west of the area this afternoon so current thinking is that
better chances for more widespread rain/storms will be across
central KS this afternoon with more isolated to scattered showers
further east. With the ample cloud cover and precipitation,
temperatures will not warm much this afternoon, topping out in the
upper 60s to mid 70s. Expect some 20-30 PoPs to persist into early
Tuesday morning as the upper low pushes into western Missouri.

As the low exits the area through the morning Tuesday, clouds behind
the trough axis will begin to scatter out through the afternoon from
northwest to southeast. A bit more sunshine should help us warm up
into the mid to upper 70s by the afternoon, but could be a touch
cooler if cloud cover takes longer to burn off. Attention then turns
to Wednesday as a large Arctic low digs south out of Canada and into
the central US. This system will act to push a surface cold front
through the area from north to south. Ahead of the boundary,
compressional warming and southwesterly winds should help to warm us
into the low 80s. Current guidance positions the frontal boundary
through the area by the early afternoon Wednesday and with CAPE
values increasing to 1000-2000 J/kg, increasing northwest shear
vectors and convergence along the front, a few storms along the
boundary that can develop could become strong to severe. At this
time, the main hazards would be damaging winds and large hail but
given the progressive nature of this system, timing of the front
still could change.

Cool air filters in behind the front by Thursday with afternoon
highs struggling to warm much higher than the low 70s. With
dewpoints in the 50s during the afternoon and skies mostly clear,
Thursday looks like a very nice day! A few more surges of cold air
push in from the north Friday and into the weekend as reinforcing
waves push into the Great Lakes and northern Plains. This should
keep temperatures into the weekend and early next week cooler than
average. Not a bad start to September!

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 623 AM CDT Mon Sep 1 2025

Scattered showers and MVFR CIGs will remain the course for much
of the TAF period today. Went ahead and added a PROB30 group in
for KMHK this afternoon to account for a possible thunderstorm,
but most precipitation should remain just rain for the most
part. KTOP and KFOE may see some ceiling improvement into VFR
later this evening outside of any precipitation that lingers
into the overnight hours of the TAF.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Griesemer
AVIATION...Griesemer