textproduct: Topeka

KEY MESSAGES

- Unsettled weather with chances for showers and storms remain in the forecast through Friday morning.

- Hot and dry weather is expected to return this weekend and early next week.

DISCUSSION

Issued at 248 AM CDT Wed Aug 5 2026

Early this morning, water vapor satellite imagery and upper air analysis showed a broad upper level trough across the northern Plains, with the trough axis extending southward to the KS border. A broad upper level ridge extended from southern CA, east into west TX. A cutoff low was located across the southeast US.

The 6Z surface map showed a cold front extending from eastern IA, southwest across northwest MO, southwest across east central KS (from west of LWC, to west of EMP). The front then extended southwest into northwest OK, then west across the northern TX PNHDL. Behind the front across the northern and western counties of the CWA, temperatures were in the mid 60s. Ahead of the front across portions of east central KS, the temperatures were in the mid 70s.

Today through Tonight:

The southern extent of the northern Plains H5 trough will shift east-southeast across KS this afternoon. Most CAMs show the surface front across east central KS, shifting south of the CWA by this afternoon. A lead perturbation within the H5 trough will be lifting northeast across IA. The only CAM that shows higher QPF is the Nam12. Most others only show isolated showers through the day north of the front. Highs this afternoon will only reach the mid 70s across the northern counties of the CWA. Farther south, closer to the front, highs will reach the lower to mid 80s across the southeast counties.

Tonight, the LLJ will increase from the southwest up to 30 KTS. The resulting isentropic lift will provide enough ascent for scattered to numerous elevated thunderstorms to develop, with the higher Pops around 60 percent across the east central KS. A few of the storms could be strong given steep mid-level lapse rates, close to 1000 J/KG of MUCAPE, and 30 KTS of effective shear. The primary hazard from any strong storms will be small hail and brief heavy rainfall.

Thursday through Friday:

The broad H5 trough will move east into the upper Midwest and mid MS River Valley on Thursday. The surface front will move southward and become stationary across northern OK. A mid-level perturbation will dig southeast from the northern High Plains across NE and KS, while a southerly LLJ will increase to 30 KTS. The LLJ jet will cause isentropic lift, and combined with ascent ahead of the H5 trough will cause showers and elevated thunderstorms to develop Thursday evening into early Friday morning. NBM PoPs are over 80s percent across the central and east central counties of the CWA from 6Z-12Z Fri.The LREF forecast over a 50 percent chance that east central KS will receive 0.25" or more of QPF Thursday night through Friday morning. The surface front will lift north into NE by Friday evening. The H5 ridge across the southwest US will build east across central High Plains into southern KS and northern OK. This should keep any mid-level perturbations digging southeast to the north and east of the CWA, so the rain chances will drop during the afternoon hours of Friday.

Highs on Thursday will reach the lower 80s north to mid and upper 80s south, with more insolation during the afternoon hours.

Friday night through Monday:

The extended range models are in good agreement with the southwest US H5 ridge axis expanding east into the southern and central Plains by early next week. Highs will warm into the upper 80s to mid 90s on Saturday, with lower to mid 90s Sunday and Monday. Southerly surface winds will advect richer moisture northward Sunday and Monday, thus afternoon dewpoints across east central KS may not mix out much, with dewpoints in the lower 70s. Therefore, afternoon heat indices may reach the 100-105 degree level across east central KS for Sunday and Monday afternoon.

Monday night through Wednesday:

The GFS and Canadian models forecast the H5 ridge to retrograde westward into NM/west TX. The ECMWF model forecast the H5 ridge to remain in the region with a slight shift southward of the center of the H5 ridge axis into TX. If the GFS and Canadian models turn out to be correct, the mid level flow will become northwesterly and there may be a chance for showers and thunderstorms ahead of any embedded perturbation in the northwest flow aloft. The ECMWF looks to be drier and a bit hotter with high only retreating slightly into the lower to mid 90s.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1247 PM CDT Wed Aug 5 2026

Expect that IFR cigs hang on for part of the afternoon around KMK while mostly marginal VFR cigs hold around KTOP/KFOE. The upper wave shifts east across the area slowly into this evening before exiting into the overnight early Wednesday morning. The persistent clouds help limit the thunderstorm potential so have removed mention of TSRA into the overnight period. While some instability will likely help a few updrafts become established enough to develop lightning, expect mostly a period of isolated showers redevelop late this evening/overnight. Potential for low cigs and IFR conditions occurs going into the 12Z period into tomorrow morning but confidence is too low to go prevailing IFR at this time. Better confidence is off to the north and northeast of the terminals.

TOP WATCHES/WARNINGS/ADVISORIES

None.