564
FXUS63 KTOP 302340
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
640 PM CDT Sat Aug 30 2025

.KEY MESSAGES...

- Occasional showers and storms are expected to affect the area
  through Monday.

- Average rain amounts are expected to be around 1 inch with
  higher amounts relatively isolated.

- Below normal temps should continue with a noticeable cool
  down expected Wednesday and Thursday behind another cold
  front.

&&

.DISCUSSION...
Issued at 215 PM CDT Sat Aug 30 2025

19Z water vapor imagery showed an upper level low over northern
NEB and southwestern SD that is cutoff from the mean
westerlies. Upper level ridging was noted over CA with a closed
low off the coast of the Pacific Northwest. Surface obs placed
high pressure over the Upper Midwest with low pressure over the
southern high plains. This favored weak southeasterly low level
flow.

For tonight through Monday, The upper low to the northwest of
the forecast area will remain the dominate weather feature
providing forcing for showers and an occasional thunderstorms.
With it cutoff from the mean flow, the system shouldn`t move out
of the area very fast. Models continue to show only weak
instability with mid level lapse rates between 5 and 6 C/km. But
forecast soundings do show a couple hundred J/kg of CAPE so
there could be some rumbles of thunder. Models generally show on
average QPF around 1 inch and if there is some cellular
convection maybe some amounts of 2 inches or more. But this
looks to be isolated at best, so there is no plan to issue a
flood watch at this point. Cloud cover and precip is forecast to
keep highs around 70 and into the middle 70s.

There is still good agreement in a cold front pushing south
through the area on Wednesday. Models have come into slightly
better alignment with the overall pattern and now the GFS is
showing some potential for precip with the front. As a result
the NBM has trended POPs higher for Wednesday and think this is
appropriate. Then some cool Canadian air builds in for Thursday.
This should clear out the low level moisture and bring dry
weather to the region while Thursday`s highs struggle to get to
70. This is within the 25th and 75th percentile of the
ensembles so have not made any changes. The biggest differences
between the models is how quickly the surface ridge weakens and
moves off to the east. Think the NBM is a reasonable forecast
with temps warming back to near 80 by Saturday.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 639 PM CDT Sat Aug 30 2025

The closest lightning observed thus far has been near Smith
Center, well outside of terminals. With that in mind, plus weak
lapse rates, think the probability of TS impacting terminals is
too low for a mention at any particular time period. Periods of
showers will continue on and off throughout the TAF period with
mostly light rainfall, although brief moderate rain may be
possible along with brief cig/vis reductions. Guidance shows
more widespread lowering of cigs from MHK westward overnight
through most of Sunday. Have kept mention of MVFR cigs limited
to MHK, but will need to watch trends to see if this will move
far enough east to impact TOP/FOE as well.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Picha