textproduct: Topeka

KEY MESSAGES

-A conditional threat for severe storms continues this evening, however, some uncertainty exists in whether storms develop.

-Best chances for storms early week will be in central KS. Chances increase eastward later in the week.

-Hot and humid to start the week, slightly cooler midweek.

DISCUSSION

Issued at 148 PM CDT Sun May 31 2026

The main focus in the short-term is on the potential for severe thunderstorms this evening. Looking at the synoptic pattern, southwest flow persists aloft with an H5 trough axis across the Northern Plains. Water vapor isn't showing much in the way of shortwaves within the southwest flow as of midday. At the surface low pressure is over northern Oklahoma and southern Kansas early this afternoon. Instability has been building in the wake of this morning's thunderstorm activity, although cloud cover is hampering temps/dew points and associated instability a bit. The cloud cover could continue to be a factor. However, most models agree on a quick increase in instability into the evening with over 3000 J/kg of MLCAPE in eastern KS by 21/22Z. The 18Z TOP RAOB still shows a cap with 14C at 750mb. RAP forecast soundings show a similar cap, but erode it by around 01/02Z. Some CAMs show storm initiation in our southeastern counties around that same timeframe. Have kept POPs only around 30 percent given uncertainty that remains on a forcing mechanism and whether the cap can be overcome. If storms do develop, there should be enough instability and deep layer shear to support supercells with a damaging wind and hail risk. Backed sfc and low level winds would also aid in a tornado risk with both RAP and HRRR forecast soundings showing over 100 m2/s2 of 0-1km SRH and over 200 m2/s2 of 0-3km SRH.

Monday looks hot and humid with highs reaching the upper 80s and low 90s. Most of the day should be dry but chances for storms will begin increasing again Monday night and early Tuesday, mainly in central KS where models show impacts from a shortwave H5 trough. A mid-level ridge will build over the area early in the week and a sfc ridge will move in from the northeast midweek. That set up should keep the main axis of storms in central KS until the upper ridge advances eastward as an upper trough moves across the far northern CONUS. Shortwaves aloft can be tough to predict several days in advance, but in general, POPs will increase eastward late in the week as that ridge pushes east. The 12Z run of long range models continue to show a storm system moving over KS next weekend, which would keep rain chances around. Temperature-wise, a slight cool down is expected through midweek due to the sfc ridge nudging in from the east.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1213 PM CDT Sun May 31 2026

Have included a PROB30 group at TOP/FOE this evening where there is potential for thunderstorm impacts. Outside of storms, VFR is expected to continue until tonight when patchy fog development is possible. Have enough confidence in reduced visibilities to go ahead and include MVFR for a few hours tonight/early Monday at all sites. However, if fog does develop, IFR cannot be ruled out. Updates will be made if confidence grows. VFR returns after 14Z Monday.

TOP WATCHES/WARNINGS/ADVISORIES

None.