textproduct: Topeka

KEY MESSAGES

- Hot weather is forecast for today with heat indices around 105 degrees. A heat advisory remains in effect for today.

- Better chances for showers and storms are expected Wednesday through Friday with high in the 80s.

- A hot and dry pattern is forecast to redevelop this weekend causing temperatures to warm back into the middle and upper 90s by Sunday.

DISCUSSION

Issued at 225 AM CDT Mon Jul 20 2026

The 07Z water vapor imagery showed the center of the upper ridge over the central Rockies with the mean westerlies across the northern plains and into the Great Lakes. Surface obs showed a weak surface pattern remained over the central plains favoring light southerly flow.

For today models show the upper ridge expanding east with height rises across the state. This is expected to help mid level temps warm with 700MB readings of 13C or better progged to spread over the forecast area this afternoon. This should increase inhibition for surface parcels marginally while the upper ridge favors general subsidence. So think we should avoid the afternoon pop up showers today. If a shower were to form, it most likely would be across east central KS where the influence of the upper ridging and inhibition should be weaker. Operational solutions continue to support highs in the upper 90s and around 100 degrees. Still the main question for the heat advisory is how much dewpoints will mix out this afternoon. And models don't really show much of a different story from the past couple days. Dewpoints across north central KS have held in the upper 60s the last couple afternoons. With a light southwest wind possibly helping a little deeper mixing, have dewpoints falling into the middle 60s by the late afternoon. Still heat indices should be near 105. And for the eastern counties where dewpoints should remain in the lower 70s, there is reasonable confidence for heat indices to be around 105 degrees. So haven't made any chances to the advisory for today.

Tuesday should see a frontal boundary push south through the day with winds becoming north and northeast. However there isn't a lot of cold air with this boundary and models want to pool some moisture behind the front. Because of this highs should still make the mid and upper 90s along and south of the KS river. With the moisture along the boundary, heat indices could be near 105 through the mid- afternoon for Anderson and Coffey counties. So went ahead with an advisory for those two counties Tuesday. Models still show some warm air at 700MB with no real wave to weaken the capping inversion. So the boundary is forecast to move through the area dry.

Wednesday through Friday should see the upper ridge shift over the southern plains with shortwave energy influencing the forecast area. Models continue to point towards a better defined vort max rounding the upper ridge for Wednesday night and Thursday with a second wave within the northwest flow for Friday. The NBM has come in with higher POPs for these times and don't see a reason to change them. The ensembles tend to have the greatest spread in temps for Friday and into the weekend as they struggle with how quickly to weaken the surface ridge and bring return flow back into the central plains. With a reasonable chance for precip through Friday, think the NBM is on track with keeping highs in the 80s.

For the weekend, the upper ridge is progged to re-amplify over the central Rockies pushing the westerlies back north of the forecast area. This should enable a dry and hot weather pattern to redevelop.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 540 AM CDT Mon Jul 20 2026

Upper ridge building in with general subsidence should keep VFR conditions in place.

TOP WATCHES/WARNINGS/ADVISORIES

Heat Advisory from 11 AM this morning to 9 PM CDT this evening for KSZ008-KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023- KSZ024-KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040- KSZ054-KSZ055-KSZ056-KSZ058-KSZ059. Heat Advisory from 11 AM to 7 PM CDT Tuesday for KSZ058-KSZ059.