textproduct: Topeka

KEY MESSAGES

- Thunderstorms currently moving south across Nebraska may produce damaging winds and large hail across far northern KS before weakening as they move farther south towards Interstate 70.

- There are additional chances for showers and storms Friday into the weekend, but low predictability of timing and location leads to low confidence.

- Temperatures stay near average through early next week.

DISCUSSION

Issued at 128 PM CDT Wed Aug 19 2026

The current short term focus is on a complex of severe thunderstorms moving southeast across eastern Nebraska. Morning showers and lingering clouds have limited instability across northeast Kansas, so we should see a weakening trend as the complex continues south. The question is how fast will these storms weaken? Recent CAM guidance weakens them below severe criteria before they move into Kansas, but given the current organization of the line it seems plausible some low-end severe risk will persist into Kansas. This would mainly be 330-700 PM across the northern tier or two of counties, where clearing skies have allowed 2000-3000 J/kg of ML CAPE to develop. By the time storms near the I-70 corridor towards sunset, more confident they will be fizzling out, given increasing CIN with southern extent and nocturnal destabilization.

Surface ridging builds in overnight, resulting in calm and mostly clear conditions. With lingering surface moisture, expecting some patchy fog to develop, particularly in the favored river valley locations. Thursday should remain dry as surface ridging remains in place, though can't rule out a few overnight showers and storms towards central KS with the remnants of earlier storms farther northwest. Some patchy shallow fog appears likely again Thursday night across eastern KS, where calm and mostly clear conditions should persist.

Friday into the weekend and early next week, the region will remain under northwest flow aloft as upper ridging strengthens to our west. With several weak shortwaves moving through this flow, we should see another chance or two at scattered showers and storms. The first and best of these chances looks to arrive Friday and Friday night. Exact timing and coverage remains uncertain, as upstream convection Thursday night into Friday morning should have a big impact on where any storms develop Friday PM. But an unstable and seasonably sheared environment will be in place across much of the area, especially NW towards north-central KS. So will have to watch for a few stronger storms, conditionally. Temperatures throughout the first half of next week will also be tied to clouds and precipitation, but overall look to stay near average values.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1232 PM CDT Wed Aug 19 2026

The current IFR/MVFR ceilings near KTOP should be short- lived, with VFR ceilings persisting for the remainder of the period. Will have to watch the complex of storms moving south out of Nebraska this evening. Uncertain how far south these storms will get before dissipating, with KMHK seemingly having the best chance of a storm at this point. Afterwards, the night will turn clear and calm, with some patchy fog likely developing within the main river valleys.

TOP WATCHES/WARNINGS/ADVISORIES

None.