textproduct: Topeka

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.