169
FXUS63 KTOP 062321
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
521 PM CST Sat Dec 6 2025

.KEY MESSAGES...

- Mainly dry weather is expected through next week.

- Temperatures will bounce around as occasional cold fronts pass
  through the region.

&&

.DISCUSSION...
Issued at 140 PM CST Sat Dec 6 2025

19Z water vapor imagery showed a closed upper low over the Hudson
Bay with ridging well off the coast of southern CA. This pattern had
set up northwest flow across the northern Rockies and through the
central plains. Surface obs showed a trough of low pressure from
central NEB back into the southern high plains. Radar has shown some
weak returns moving across northern parts of the state, but it was
not obvious that any precip was reaching the ground. The shortwave
responsible for the light radar returns should push east of the area
early this evening.

In the short term, concerns are whether dense fog may redevelop this
evening ahead of an advancing cold front. Forecast soundings keep
some wind in the boundary layer. But the mid cloud deck is expected
to pass to the east as the prefrontal trough moves in. Most guidance
does not show any restricted visibility and the 12Z HREF had
probabilities for dense fog at 50 percent or less. While conditions
don`t look ideal, think winds could lighten up enough within the
prefrontal trough for some potential for patchy fog over parts of
northeast and east central KS. Will include a mention of patchy fog
in the forecast. Once the cold front pushes south through the pre
dawn hours, increasing winds should promote better mixing and favor
a stratus deck that could linger into Sunday afternoon due to a
relatively strong inversion.

For next week, models are in agreement with the northwest flow
persisting. There are periodic shortwaves progged to move through
the pattern which tend to track to the north and east of the
forecast area. The one opportunity for precip may come Wednesday
night as one of these waves may bring mid level frontogenesis into
northeast KS. Have opted to stay with the NBM for now which keeps
POPs around 10 percent given the very light nature of the QPF from
the models. Ensembles and cluster analysis shows the main
variability in the forecast is the amplitude of the ridge to the
west and trough to the east. This becomes evident by Thursday and
Friday with 00Z ensembles showing 15 to 20 degrees of spread between
the twenty fifth and seventy fifth percentiles. In the operational
solutions this is seen by a stronger surface ridge building south in
the 12Z GFS versus the 12Z ECMWF. The operational GFS also seems to
be more amplified with the shortwaves than other guidance. The NBM
trended cooler with temps for Thursday and Friday which seems
reasonable giving a good signal for Canadian high pressure to move
in. Though the GFS may be to cold with temps given it being quite a
bit stronger with the surface ridge than other operational
solutions.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 519 PM CST Sat Dec 6 2025

VFR becoming IFR by early morning. A cold front will move
through around 08z tonight. Behind the front, wind will shift
out of the north and CIGs will fall to IFR. Low stratus will
remain through most of the period, potentially scattering out by
the end of the period.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Jones