textproduct: Topeka

KEY MESSAGES

- A few morning thunderstorms will be possible across northeast KS

- Warming up Today, with heat indices peaking near 102 degrees. A few strong to severe storms possible across north-central KS late this afternoon and evening.

- Cold front stalls across the area Tuesday into Wednesday. Cool with pockets of heavy rain and storms north of the front, warm with more widely scattered storm chances south of front. Tuesday night into Wednesday morning areas north of I-70 may see a widespread heavy rainfall.

DISCUSSION

Issued at 234 AM CDT Mon Sep 14 2026

Early this morning an upper level trough extended from western MT, southward across the Great Basin. An downstream upper level ridge was located across the Plains states. An upper trough was moving east across the eastern Greet Lakes and eastern OH River Valley.

The 6Z surface map showed a warm front extending from northwest AR and northeast OK, then stretched northwest across west central KS into eastern CO. The warm front will undergo frontolysis Today and reform across central NE. Isentropic lift and WAA will cause elevated showers and thunderstorms to develop across southern NE/northeast KS.

Today through Tuesday:

The better chances for showers and elevated thunderstorms will be across northeast KS, though, some isolated storms may form a bit farther southwest across portions of east central and north central KS through 12Z MON. As the warm front reforms farther north of the CWA later this morning the isentropic lift will shift northeast into northern MO/IA. Expect gusty southerly winds to develop through the mid and late mooring hours and continue through the afternoon hours. The WAA within the warm sector will help high temperatures to reach the upper 80s northeast to mid 90s west. The PBL will mix deeper across the western counties, thus surface dewpoints wil mix out into the mid to upper 60s during the afternoon hours. Eastern KS should keep lower 70 dewpoints. Maximum heat indices will be in the upper 90s to near 103 across the eastern counties of the CWA. Heat indices will be a bit lower across north central KS with mid 90s to around 100 degrees. Since maximum heat induces will remain below 103 degrees, I will not issue a heat advisories, but it will feel hot and humid for this time of year.

As the H5 trough lifts northeast across the central High Plains into the northern Plains late this afternoon, a surface cold front will move east across west central KS. Thunderstorms will develop along this front from eastern NE, southwest into north central KS, then southwest into southwest KS. The higher instability and effective shear values will be located across eastern NE/western IA where there will be a better chance for supercell thunderstorms to develop, which could produce all hazards. Farther southwest along the front the instability will be less, with MLCAPES in the 1000-2000 J/KG range. Forecast soundings show inverted V profiles, so any thunderstorm that develops in this environment late this afternoon may produce strong downdrafts. Effective shear will be 25 to 35 KTS, thus any organized updraft that develops with mid level rotation may produce large hail along with the damaging wind gusts. The strong to sever thunderstorms will move into the western counties during the late afternoon and evening hours. After sunset the line of storms may weaken a bit but the front should slowly shift southeast through the night. If thunderstorms train along the front during the evening and overnight hours there may be some localized flooding. PWs across north central KS will in the 1.5-2.0" range.

Tuesday, the H5 trough will lift from the northern Plains Monday night into Ontario Canada by Tuesday afternoon. The strong southwesterly H5 jet will lift northeast of the area. The surface front will shift southeast across the CWA and most CAMs and CPMs forecast the front along a LWC to EMP line. Ahead of the front MLCAPE will be in the 1500-3000 J/kg range and effected shear will be 20 to 35 KTS. The environment Tuesday afternoon will be sufficient for strong to severe thunderstorms with damaging wind gusts and half dollar size hail. There will be elevated storms northwest of the front but MUCAPE values will be less than 500 J/KG, so if there is any hail it should be small. Most numerical models show a fairly progressive front, pushing southeast of the CWA after 00Z. I'm not sure how much training of thunderstorms will occur Tuesday afternoon if the front is progressing to the southeast.

Tuesday night through Wednesday:

The surface front will stall out just south of the CWA and the retreat northward as a warm front. Elevated thunderstorms will develop north of the front and continue into the morning hours as the front lifts northeast across the CWA. By Wednesday afternoon the front will be along the NE border. There may be prolong period of heavy rainfall Tuesday night into Tuesday morning as a 40 to 50 KT LLJ develops and advects 14 deg C dewpoints at 850mb northward across eastern KS. Some of these elevated storms may be strong to severe and producing hail up to 1.5". Also, PWs will be over 2.0", so any areas with prolong heavy rainfall may see localize flooding.

Wednesday night through Friday:

The extended range models are in good agreement with moving an H5 trough east into the western US. This will expand the H5 ridge across the central Gulf States and mid MS River Valley westward into the central Plains. Most of the perturbations rounding the H5 ridge will remain to the north of the CWA across central NE and IA. So, expect mostly dry conditions with highs in the mid 80s north to lower 90s south.

Friday night through Monday:

The extened range models slowly bring the western H5 trough east into the Plains. The H5 trough will fill as it move east into the Plains by Monday. Southwest H5 flow with embedded perturbation will provide chances for scattered showers and thunderstorms through the weekend. GFS is a bit more progressive and brings the front southeast across the area on Monday, with decreasing rain chances. Highs this weekend will be in the lower to mid 80s on Saturday, then cooling into the mid 70s to lower 80s on Sunday. If the front moves through Monday morning, then high on Monday afternoon will only reach the lower to mid 70s.|

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1232 AM CDT Mon Sep 14 2026

Expect VFR conditions through the next 24 hours. There may be an isolated shower or thunderstorm around the terminals between 8Z and 13Z MON. Southerly winds will increase through the mid and late morning hours up to 13 to 17 KTS with gusts of 24 to 30 KTS during the afternoon hours. The winds will only diminish slightly after 2Z TUE. There may be moderate low-level wind shear this morning and again Tuesday morning, with low-level wind shear of 25-30 KTS.

TOP WATCHES/WARNINGS/ADVISORIES

None.