747
FXUS63 KTOP 281105
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
605 AM CDT Tue Apr 28 2026

.KEY MESSAGES...

- A period of cool weather is forecast through the workweek.

- Scattered showers are expected to develop today. Rain should be hit
  or miss before coming to an end by this evening.

- There is another chance for light precipitation on Thursday.

&&

.DISCUSSION...
Issued at 221 AM CDT Tue Apr 28 2026

07Z water vapor imagery showed a shortwave lifting through the Great
Lakes with an upper trough axis propagating across the central
Rockies. The upper level jet was noted across northern Mexico and the
southern plains. Surface obs showed high pressure building down
through the northern plains with a cold front along the Red River
Valley.

For today a low amplitude shortwave is expected to lift along the
NEB/KS state line. The forcing from this wave along with some steep
mid level lapse rates is expected to allow for some showers to
develop. But limited moisture within the surface ridge and prospects
for moisture return also limited makes it hard to see coverage more
than isolated or scattered. The mid level lapse rates may also allow
for some lightning and thunder, but overall instability is progged
to be modest for a mid level parcel with no surface based
instability. So chances for intense thunderstorm activity appear to
be low. Models show high pressure to slowly push south today with
some cold air advection for much of the day. This with partly to
mostly cloudy skies is forecast to keep temps in the upper 50s to
near 60. Once the shortwave passes to the northeast this afternoon,
precip chances should diminish quickly.

There is pretty good agreement among the operational models through
the end of the week and limited spread from the ensembles. So don`t
see any reason to deviate from the NBM. The synoptic pattern of the
upper jet remaining south of the forecast area while an upper low
slowly moves from the northern plains towards New England favors
continues surface ridges moving south and a period of cooler than
normal weather. Models show some light precip possible thursday as
some mid level frontogenesis develops over the state. But this
forcing may be battling with some confluent mid level flow. So POPs
are in the 20 to 40 percent range.

There is a little more spread in the ensembles by the end of the
weekend and into next week. This is largely a function of how far
west the track up upper energy digging down the back side of the
upper low is. The NBM`s highs near 80 for Sunday and Monday are
above the seventy fifth percentile compared to the ensembles. And
individual 00Z runs show this spread in the 925 and 850 temp progs.
Have stuck with the NBM forecast, but think there is more room for
temps to trend cooler than warm for Sunday and Monday. As for precip
chances this weekend and into next week, models keep the better
synoptic scale forcing to the northeast and west of the forecast
area. So precip chances look to be driven more by meso scale
features and this has kept POPs from the NBM generally less than 20
percent. This looks like a reasonable forecast at this time.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 605 AM CDT Tue Apr 28 2026

Still don`t have a great deal of confidence in the MVFR stratus
forecast. The general consensus is for the CIGS to improve by the
late morning and I have the forecast improving. But the timing could
be a little later. CAMs still show some isolated showers possible
through midday. Opted to include a PROB30 for the chance of a brief
shower at the terminals. Then tonight the question is whether the
stratus redevelops. Mixed signals from the various guidance has me
leaning optimistic with CIGS above 3KFT. But the NAM would bring the
low clouds back in. Will have to reevaluate this as later runs come
in.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters