749
FXUS63 KTOP 181950
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
150 PM CST Tue Nov 18 2025

.KEY MESSAGES...

- Some patchy fog could redevelop late tonight and into Wednesday
  morning.

- Rain chances increase Wed night and through the day Friday. The
  highest chances (70-80%) look to be late Thu night and Fri morning.

- Next weekend is shaping up to be dry with seasonal temperatures.

&&

.DISCUSSION...
Issued at 150 PM CST Tue Nov 18 2025

19Z water vapor imagery showed an active pattern with a closed upper
low over the southern CA coast with shortwaves over the Upper
Midwest and the Northern Rockies. Surface obs placed the center of
low pressure over central MO with a trailing cold front into the Red
River valley. Surface high pressure was gradually building into the
forecast area.

For tonight and Wednesday, shortwave ridging with little or no
dynamics for vertical motion is expected to keep things dry. So the
main concern turns to fog potential late tonight and Wednesday
morning. Models show the center of a surface high setting up over
northeast KS Wednesday morning. This should allow the boundary layer
to decouple with winds becoming light and variable. However
increasing high clouds from the southwest should inhibit some of the
radiational cooling. There is enough signal from the models of fog
potential and have maintained some patchy fog wording in the
forecast. However the 12Z HREF has come in with lower probabilities
for fog than it had yesterday and this along with the expected high
clouds limits confidence in how dense or widespread it may be. So
this will be something for later shifts to keep an eye on. Lows
tonight are forecast to drop into the middle and upper 30s. A little
more cloud cover through the day Wednesday may keep highs a few
degrees cooler in spite of a return to southerly low level flow.

There is reasonable agreement from the models with the upper low
over the southwest lifting out into the central plains Thursday
night and Friday as an open wave. Ahead of the wave, mid level warm
air and moisture advection could cause some showers to develop
Wednesday evening. But the main forcing for precip is expected to
impact the area late Thursday night and through the day Friday. Mid
level lapse rates could be steep enough Wednesday night for a rumble
or two of thunder across east central KS. Otherwise models show the
forecast area remaining north of the surface low and on the cool
side of the system. This should bring periods of rain to most areas
late Thursday night and Friday morning. Rain amounts look to range
from around a half inch north to an inch and a half over east
central KS. These amounts from the NBM are closer to the 75
percentile of the 00Z ensembles, so there is some room for these
amounts to end up lower. This is especially the case across the
northern counties where a northernly wind and some low level dry air
advection could create a sharp gradient in rainfall. The clouds and
precipitation should make Friday feel pretty cool and highs should
be in the 50s.

Shortwave ridging is progged to redevelop for the weekend before
another upper wave lifts out from the southwest. Models have
converged somewhat on timing of this cutoff low. Although there
doesn`t appear to be a kicker immediately upstream, so I wouldn`t be
surprised with the system progresses a little slower than the GFS
shows. Think the better chances for more rain look to be Monday
night and Tuesday. Temps to start off next week look to be
seasonable with precip remaining liquid. A quick look towards
Wednesday and Thanksgiving have the models showing a colder airmass
moving in with a hint at some potential for wintery weather
Wednesday night. The 00Z ensembles showed the probability for
measurable snow was around 10 percent. So we`ll watch later runs for
some consistency, but it is hard to have much confidence in an
embedded wave and mid level frontogenesis this far out in time.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1052 AM CST Tue Nov 18 2025

The center of a surface ridge is forecast to setup over the area
Wednesday morning. This should allow the boundary layer to decouple
with winds becoming calm. However increasing high clouds this evening
may inhibit ideal radiational cooling and FG potential. The 12Z HREF
shows a lower potential for restricted visibilities at around 10
percent. But MOS guidance and forecast soundings from the RAP are
signaling some FG potential. With the expected high clouds, will keep
visibilities in the MVFR range and base timing off the RAP
soundings.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters