422
FXUS63 KTOP 052318
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
518 PM CST Fri Dec 5 2025

.KEY MESSAGES...

- Fog possible overnight into the morning, although confidence is
low on how much of it or exactly where.

- Temperatures go up and down through the next week: seasonal
through Saturday, cooler Sunday, then warming back up into mid-week.

- Low chance for a brief rain shower in northern KS Saturday
  afternoon, otherwise looking dry through the next week.

&&

.DISCUSSION...
Issued at 250 PM CST Fri Dec 5 2025

Water vapor imagery continues to show broad mid-level troughing
across most of the CONUS with moisture streaming along the Gulf
states into the southern Atlantic states, all just south of the
upper jet. Within the broad troughing pattern, a couple of
shortwaves are noted: one moving through the Central Plains and
another in central Canada. The combination of these has led to a
weak sfc troughing pattern across the state as we sit in between the
sfc lows that have developed in response to these shortwaves.
Another shortwave aloft is noted near the Pacific Northwest, and
this will set the stage for Saturday`s weather. In the meantime, our
only impact from the wave near us is high cloud cover, which will
slowly push south into tonight. The clearing skies plus light winds
from the weak sfc pattern may result in enough radiational cooling
for fog to develop overnight into early Saturday morning. That said,
there is a wide range in the guidance as a few models suggest
widespread fog development while others produce little to no fog.
The higher resolution models are on the warmer side of temperature
guidance for Saturday morning, so that could be the reason for the
discrepancy. Forecast soundings seem to suggest shallow fog as we
get closer to sunrise. So will need to monitor this potential as
well as how widespread or dense it might get.

The rest of Saturday sees the Pacific shortwave strengthening a bit
as it moves through the northwest flow across the Missouri River
Valley. There is still some variation in how far south the sfc low
will track even with CAM guidance, as some solutions bring it as far
south as the KS/NE border while others keep it north into Nebraska.
Overall the best PVA is north of the area with most precip north of
the sfc low, but there does look to be enough isentropic lift ahead
of the sfc cold front to produce some light precip in northern KS
Saturday afternoon. CAMs support this as well with some light
reflectivity shown mainly north of I-70. Forecast soundings show
only a brief time window (1-2 hours) where precip could reach the
ground. Temperatures are warm enough to support rain, and forcing
for ascent weakens by the time colder air arrives. So have added
slight chance PoPs north of I-70 to account for the possibility of a
brief rain shower.

Colder air advects into the area behind the front, bringing
temperatures back down for Sunday as highs reach the mid 20s to mid
30s. From there, northwest flow aloft remains persistent into the
middle of next week with the track of additional systems currently
favored to keep precip northeast of the area. The low-level winds
take on a downsloping component by Tuesday, favoring a warm-up with
highs reaching the 50s. Confidence decreases in the temperature
forecast by the end of the week as models diverge on the evolution
of the upper trough to the east as well as embedded waves within the
flow aloft.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 506 PM CST Fri Dec 5 2025

VFR at all TAF sites through the TAF period with light and
variable wind becoming southerly by tomorrow morning. Fog may
develop late tonight south of the terminals. It could advect
into the the Topeka terminals around 12z, but confidence in fog
at KTOP/KFOE is too low at this time to mention in the TAF.

&&

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

&&

$$

DISCUSSION...Picha
AVIATION...Jones