textproduct: Topeka

KEY MESSAGES

- Extreme Heat Warning remains in effect for areas south of the Hwy 36 corridor until this evening.

- Isolated storms are possible early this evening, although better chances (50-70%) come overnight mainly north of I-70.

- Relief from the heat comes Sunday and Monday with highs mostly in the 80s.

- Periodic rain chances return mid-week, mainly during overnight periods Tuesday night and Wednesday night.

DISCUSSION

Issued at 408 AM CDT Sat Aug 15 2026

Surface trough axis remains draped across KS with a stationary boundary holding across the center of the CWA. At the upper levels, we remain on the northwest periphery of the ridge dominating the Deep South while a trough is noted over the West Coast states. The nose of the LLJ has pushed north of the KS/NE border and helped steer the storms that began late last night into the MO/IA/IL vicinity. A couple of other batches of storms are making their way through western KS and NE, and a convectively induced vort max is noted in that area on water vapor imagery. Some showers and weak storms left over from that activity may survive into north central KS this morning before dissipating around mid-day. How far south any precip and cloud debris ends up as a result of this leads to some questions on how hot temperatures will actually get today, particularly in counties along the KS River Valley and northward. If the sfc boundary hangs near its current location, clouds clear out soon enough, and southerly winds pick up enough, then most locations within the Extreme Heat Warning should be able to heat up and see heat indices in the 105 to 110 degree range. However, if the boundary sags south during the day and/or cloud cover lingers longer, then it's possible even locations along I-70 could struggle to reach heat indices of 105. Areas along and south of the Turnpike have the best chance of getting there as it stands now. Given that some hi-res guidance does still show potential for hotter temperatures with a northerly placement of the front, have gone with more of a middle ground solution on temperatures and left the warning as is for now.

Regarding storm chances tonight, there are a couple of opportunities to watch. One is with convergence along the front by early evening, although forcing looks rather weak and coverage looks isolated and short-lived. Still, if something can get going, inverted-V soundings would support strong wind gusts. The better chance for storms looks to come from another batch of convection that begins in the higher terrain and eventually makes it into north central KS overnight (probably after 1-2am). It remains uncertain how strong these storms would still be by the time they reach this area, but MUCAPE around 1500 J/kg and modest bulk shear could support a few marginally severe storms.

Any storm activity should move out Sunday morning with the front finally pushing south by then as well. This leaves us with cooler temperatures as highs are in the 80s, perhaps a few low 90s in our far southeast. Unfortunately, dew points won't be much better as they are stuck in the 70s, but the lower temperatures will still make it much more manageable. Monday looks similar as all areas should see highs in the 80s.

For the middle and especially end of next week, we transition to quasi-zonal to northwesterly flow aloft with the ridge pushed to our south. Although temperatures warm up slightly Tuesday with southerly low-level flow, the bulk of the heat should stay south of the area. Perturbations embedded in the upper flow with the low-level baroclinic zone nearby result in greater uncertainty with temperatures mid to late week. Rain chances look to be mostly during the overnight periods Tuesday night and Wednesday night, but timing and placement of those waves should come into better focus as we get closer to each day.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 629 AM CDT Sat Aug 15 2026

VFR conditions are forecast. Winds start out southerly and may turn light and variable for a few hours this afternoon before fully switching to the northeast this evening. Any storms that could develop along the frontal boundary early this evening look too isolated to mention in TAFs. Better coverage comes with a cluster of storms arriving from western KS overnight, but even this only brings enough confidence for a PROB30 group at MHK. Will hold off mention further east.

TOP WATCHES/WARNINGS/ADVISORIES

Extreme Heat Warning until 7 PM CDT this evening for KSZ020-KSZ021- KSZ022-KSZ023-KSZ024-KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038- KSZ039-KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.