828
FXUS63 KTOP 101933
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
233 PM CDT Thu Sep 10 2026

.KEY MESSAGES...

-Radiational fog likely develops tonight, especially in areas that
had recent heavy rainfall.

-A series of surface boundaries will bring rain chances back to the
area periodically throughout this forecast period, starting tomorrow
night.

-There will be at least a low risk for strong to severe storms on
Saturday and again early next week.

&&

.DISCUSSION...
Issued at 228 PM CDT Thu Sep 10 2026

Rain has cleared to the southeast as higher pressure has built in
from the north today. Cloud cover will continue to scatter this
afternoon, with sky conditions becoming mainly clear into tonight.
Tonight`s set up looks favorable for radiational fog development for
much of the area due to clear skies, light sfc winds and ground
moisture from earlier rainfall. The only possible limiting factor may
be a breeze just off the surface, as shown on forecast soundings.
Still, confidence is high enough to include areas of fog tonight and
early Friday.

The main challenge with this forecast package is then POPs -
determining probabilities and timing.

On Friday, the H5 flow becomes more zonal across KS while today`s
trough axis deepens over MO. A shortwave will pass to our north
across SD and into MN during the day. Sunshine and return flow at
sfc will allow temps to be a touch warmer, with highs likely reaching
the upper 80s. The aforementioned shortwave may then bring a sfc
boundary into southern Nebraska Friday night. A few storms could
form (20-40% chance) along the boundary and track southeast into
northern KS. Elevated instability would allow for thunderstorms, but
shear does not organized enough to produce severe storms.

The surface boundary is likely to remain over northern KS on
Saturday. There is some uncertainty in whether overnight storms
will linger into the daytime hours, but if rain and clouds are able
to clear, the environment could become increasingly favorable for
strong to severe thunderstorm development during the afternoon or
evening. Storms that develop near or just south of the boundary will
do so in an environment featuring steep lapse rates and effective
shear around 40 kts. Damaging wind gusts and small hail would be the
main hazards.

A progressive pattern has the sfc boundary lifting northward into
southern Nebraska on Sunday as a warm front. Aloft, the H5 ridge
over the south-central US may begin to transition to the east as a
strong Pacific Northwest system progresses eastward across the
northern CONUS. That would allow flow over the central US to shift
from westerly to southwesterly. Theta-e advection will create an
unstable air mass, however, a cap and lack of forcing will likely
keep conditions dry from Sunday afternoon into midday Monday. While
the Pacific Northwest system will remain well north of the area, an
associated sfc cold front looks to slide into northern KS by Monday
night. Thunderstorm chances again increase Monday night and more so
on Tuesday as the boundary interacts with the moist and unstable air
mass. Will keep POPs going into Wednesday until subsidence from high
pressure begins to limit vertical motion north of the front.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1210 PM CDT Thu Sep 10 2026

Lingering MVFR stratus is expected to scatter to VFR early this
period and continue to clear through the afternoon. Clear skies,
light winds and ground moisture from previous rain could set the
stage for fog development tonight. Felt confidence was high enough to
go ahead and include reduced visibilities in TAFs with this update.
However, adjustments to timing and flight category are likely needed
with subsequent TAF issuances.

&&

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

&&

$$

DISCUSSION...Teefey
AVIATION...Teefey