textproduct: Topeka

KEY MESSAGES

- Severe thunderstorms becoming numerous early to mid afternoon today and spreading east to southeast this evening. Very large hail, damaging winds, and tornadoes all quite possible.

- Flash flooding remains a concern through tonight especially where heavy rain fall Sunday night.

- Gusty south winds on track for the next several hours in southwestern areas.

DISCUSSION

Issued at 200 PM CDT Mon May 18 2026

Warm, humid airmass was surging north into central Kansas ahead of a cold front toward a nearly-stationary front just northeast of northeast Kansas with a modest upper wave just upstream. Instability of 3000 J/kg already commonplace in central Kansas at 17Z with 40-50 knots of deep-layer shear. Vectors for this layer remain close to parallel to the front so there is some uncertainty in how long storms can remain discrete, but some backing of low-level flow and otherwise good setup brings all severe hazards in play. Main area of concern over the next few hours is north-central Kansas with storms spreading east and southeast and becoming more widespread with time. Threats should turn more to wind versus strong tornado in eastern areas as mode shifts to more linear. Overall a more progressive system should keep storm residence somewhat limited, but areas that saw heavy rain Sunday night will not take much more rain to experience flash flooding and intense updrafts with PW values around 1.5 inches will bring quick rainfall. Storms push southeast before dawn with flash flooding threat falling off, though rivers and creeks may be high for a few more days. Surface winds

Next few days continue to look benign with modified Canadian high pressure in place with cooler temperatures. Moisture return in the mid-levels supports at least moderate precipitation chances Thursday into Thursday night but instability remains modest. A more unstable airmass should return around the holiday weekend though forcing for ascent is not readily apparent.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1223 PM CDT Mon May 18 2026

Confidence is increasing in thunderstorm potential in the 23Z-04Z window and went ahead with TEMPO inclusion. MVFR cloud should diminish soon but be more consistent after FROPA around 06Z with some chance for improvement late in the forecast.

TOP WATCHES/WARNINGS/ADVISORIES

Flood Watch through Tuesday morning for KSZ008-KSZ009-KSZ010-KSZ011- KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026-KSZ034-KSZ035- KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055-KSZ056-KSZ058- KSZ059. Wind Advisory until 9 PM CDT this evening for KSZ035-KSZ036-KSZ037- KSZ038-KSZ054.