textproduct: Topeka

KEY MESSAGES

- A slight cool down with lower humidity is expected as we begin the new week.

DISCUSSION

Issued at 157 PM CDT Sat Jul 4 2026

19Z water vapor imagery showed an MCV moving into MO but profiler data across eastern NEB with veering 500MB winds hinted at a second perturbation moving along the MO river valley too. A low amplitude wave was noted across the northern plains. At the surface, convection from earlier today caused a meso-high to set up across northeast KS with the effective surface front/inverted trough axis shunted south over northern OK.

For this evening the big picture is for redevelopment to be mainly across southern KS where an 850MB boundary is progged to be. This looks to be between KTWX and KICT right now. But there is also the development along a wind shift coming out of north central KS. I would expect this convection to only reinforce the meso-high and keep the synoptic boundary south of the forecast area. But the predictability in this weakly forced environment is poor as evident by the CAMs performance and forecast confidence remains low. With this in mind have continued with some chances for elevated showers and storms to reform. The forecast has chances for redevelopment along I-70 in the 30 to 50 percent range. Areas along and south of Ottawa to Council Grove have a better chance in the 55 to 75 percent range due to a closer proximity to the 850MB boundary. If storms develop, the RAP/NAM still prog steep mid level lapse rates with 30KT to 40KT of bulk shear. Discrete storms may have some supercell characteristics with the potential for large hail and damaging winds. But weak storm motion is expected to favor storm mergers and and eventual evolution into an MCS with a transition to damaging winds and rain. If the latest models are right, this transition may be as the storms are moving through southern KS. For areas along and north of I-70, it looks like there is a high chance for dry weather this evening.

Not a lot of changes to the forecast after tonight. There are indications of some weak vort maximum moving through the MO river valley Sunday afternoon. But most of the solutions are keeping any pop up showers east of the area. So have dry forecast with precip chances around 10 percent for northeast and east central KS. The early part of the work week should see mid-level height rises locally over the forecast area. This is progged to favor weak subsidence and dry weather for Monday and into Wednesday as temps remain seasonal. This pattern breaks down by the end of the week with a more zonal flow and weak perturbations possible. So chances for precip return to the forecast for Wednesday night through Friday.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1223 AM CDT Sun Jul 5 2026

Vsby has tanked to LIFR to VLIFR categories due to a combination of smoke from fireworks and low-level moisture leading to fog development. Not expecting to see improvement with this through the night as the inversion is well established with light low-level winds based on forecast soundings. Mixing should help to scour out the smoke and fog by around 14z with winds remaining light thereafter.

TOP WATCHES/WARNINGS/ADVISORIES

None.