textproduct: Topeka

KEY MESSAGES

- Thunderstorm chances increase Saturday afternoon, with the most widespread storms and heavy rain potential Saturday night into Sunday. Strong to severe storms and flooding will be possible.

- Shower and storm chances gradually diminish Sunday night into Monday as the front shifts east

DISCUSSION

Issued at 224 AM CDT Fri Jun 19 2026

Early this morning water vapor satellite imagery along with upper air analysis showed a broad upper trough across the mid MS River valley, with a low amplitude upper ridge across the western US. The upper flow across the Plains was from the northwest.

The 6Z surface map showed a broad surface ridge extending from the Great Lake States, southwest across northern MO. Winds were light and variable across the northern counties with light southerly winds across north central KS and the far southeast counties. A few weak isentropic lift showers were occurring across southeast KS. These showers were moving southeast and should remain southeast of the CWA early this morning.

Today through Tonight:

Southerly low-level flow will begin to transport richer moisture northward across the southern and central Plains later Today and Tonight. A LLJ of 30-40 KTS may provide enough isentropic lift for scattered showers and a few elevated thunderstorms Tonight. The better instability with MUCAPES of 1000-1500 J/KG should remain west and south of the CWA Tonight into Saturday morning. So, I'm not expecting any severe storms but if instability increases across the southern counties, then some of the elevated storms may produce small hail. The H5 ridge across the western US will shift east into the southern high Plains by 12Z SUN. An upper trough will move onshore across CA and move east into the Great Basin by 12Z SAT.

Saturday through Sunday:

The H5 trough across the Great Basin will lift east across the central high Plains by 00Z SUN. Scattered thunderstorms will develop along a pacific front/dryline across west central KS during the afternoon hours. These thunderstorms will be severe with MLCAPE of 2000-3000 J/kg and effective shear of 40 to 50 KTS. The scattered to numerous storms will congeal into a QLCS/MCS and shift east across the CWA during the overnight hours. The primary threat will be damaging wind gusts and heavy rainfall. The LLJ will increase to 40 to 50 KTS ahead of the line, with MUCAPE of 1500-2500 J/KG should keep this QLCS intense as it moves east across the CWA. 35 KT 0-3km shear vectors orthogonal to the line may develop mesovortex and possible mesovortex tornadoes in areas where a RIJ can develop within the line. Some of the CAMs are showing more of the southeasterly track in the QLCS/MCS Saturday night, so there may need to be mesoscale adjustments in the areas impacted.

Heavy rainfall totals of 1 to 3 inches will be possible in the path of the QLCS, plus lingering isentropic lift rainfall may produce an outshone 0.5" behind the exiting QLCS. The LREF has a greater than a 50 percent probability of receiving over 1.5" of rainfall from Saturday night through Sunday afternoon along and north of I-70. Therefor, I have issued a flood watch for areas along and north of I-70 from 00Z SUN through 18Z SUN for possible flooding along rivers and low-lying areas, especially areas that have received heavy rainfall during the past couple of weeks.

Sunday night through Wednesday:

A weak front will push southeast across the area on Sunday but will stall out across central OK Tuesday morning. We may see a break in the showers and thunderstorms during this period. Highs on Monday will cool back into the mid and upper 70s but will warm up into the lower to mid 80s on Tuesday and Wednesday.

Wednesday night through Friday:

Shower and thunderstorm chances will increase as an upper low deepens north of Lake Superior and northwest mid level flow develop across the Plains. A lee surface trough will develop across the central and southern high Plains. Richer 850mb moisture will advect northward across the Plains resulting in isentropic lift north of the surface front along the OK/KS border. The front will slowly lift northward as warm front by late Friday. Embedded mid level perturbations in the northwesterly mid level flow may provide more ascent for showers and storms. Highs will reach the mid 80s by Thursday and Friday.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1219 AM CDT Fri Jun 19 2026

VFR conditions likely prevail through the period. Any signal for ground fog appears to be minimal and brief so have left any mention of ground fog out at this time but if it does occur would likely be around KTOP. A light southerly breeze picks up around mid-morning. Into late this afternoon and early evening, a few high based showers and storms may form mainly around the KMHK terminal but if they persist could spread east into northeastern Kansas. Coverage appears to low to mention at this time.

TOP WATCHES/WARNINGS/ADVISORIES

Flood Watch from Saturday evening through Sunday afternoon for KSZ008-KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023- KSZ024-KSZ026-KSZ034-KSZ036-KSZ038-KSZ039-KSZ040.