textproduct: Topeka

KEY MESSAGES

- The workweek is expected to start off dry with near normal temperatures.

- There is a chance for showers and thunderstorms Tuesday night and again Wednesday night.

- Tuesday looks to be the hottest day this week. Otherwise mild temperatures are forecast stick with around to end the week.

DISCUSSION

Issued at 222 PM CDT Sun Aug 16 2026

19Z water vapor imagery and profiler data show the morning MCV has moved east of the area while surface obs had the frontal boundary slowly moving south across east central KS. The larger pattern still has a broad flat upper ridge across the southern U.S. with a handful of waves to the north.

Through Tuesday models show a west to northwest flow over the central plains. The latest RAP/NAM tend to track any convectively induced vort make from the high plains south of the forecast through Monday morning. Otherwise there isn't a strong signal of forcing that impacts the forecast area. So unless a stray shower pops this afternoon, dry weather is expected to stick around through the beginning of the workweek. The NBM has been slow to catch onto the dryer dewpoints with the surface ridge and have used more of the consensus of the short term models for the dewpoint forecast. This should keep a little bit of a dryer airmass across the area through Monday as the surface ridge passes through the area. Think the dry air should also bring some clearing skies tonight as winds become light setting up a good radiational cooling situation. Lows in the 60s that are 3 to 5 degrees below current dewpoint temps could allow for some patchy fog to develop by sunrise Monday. Decent insolation and a gradual return to southerly low level winds are expected to help push afternoon highs into the middle 80s for most locations Monday. A little stronger low level warm air advection is progged for Tuesday and have highs from around 90 to the middle 90s.

The synoptic pattern is expected to amplify during the back half of the workweek with shortwave energy somewhat subtle. Still operational solutions continue to show a signal for nocturnal showers and storms Tuesday night and again Wednesday night into Thursday morning. The NBM seems to favor the chances for precip Tuesday night, but the GFS and ECMWF show a better shortwave trough axis clipping northeast KS with some decent QPF. I would expect that once the NBM gets the 12Z data that precip chances would increase for the Wednesday night and Thursday morning time frame. The consensus has another weak frontal boundary sliding south of the area Wednesday and Thursday. This should keep highs in the 80s.

By Friday and for the weekend, the model consensus is for the upper ridge to strengthen over the intermountain west with northwest flow across the central plains. The main differences from the cluster analysis seems to be the amplitude of the pattern. For the sensible weather, the question is whether the forecast area is under the influence of surface ridging from the Upper Midwest with an easterly low level wind or are southerly winds able to advect hotter air into northeast KS. It's hard to take the GFS with its bias of over mixing the boundary layer and being to hot by 10+ degrees. And the GFS may account for a large part of the spread seen in the long range ensemble forecast. Based on the ECMWF and Canadian, the forecast temps from the NBM look plausible for now. Precip chances within the more amplified pattern will be more dependent on mesoscale features and the blend generally has chances at less than 20 percent.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1235 AM CDT Mon Aug 17 2026

With clear skies overhead and very light or calm winds taking place, think the signal for shallow fog overnight into sunrise remains valid and have maintained that mention at all TAF sites. Will monitor for adjustments to timing and flight categories as needed. Otherwise, winds stay light and variable throughout the period.

TOP WATCHES/WARNINGS/ADVISORIES

None.