textproduct: Topeka

KEY MESSAGES

- Areas of fog, potentially dense in some spots, will continue through early morning across eastern KS.

- Lowered rain chances for tonight into Saturday morning, with better chances (30-50%) late Saturday afternoon into evening. Can't rule out a few strong to severe storms during that time.

- Next best chance for rain (50-80%) comes Monday night into Tuesday, especially across northern KS.

DISCUSSION

Issued at 354 AM CDT Fri Sep 11 2026

Broad cyclonic flow is noted over the northwest portion of the CONUS with a couple of shortwaves in Canada helping to contribute to that pattern, while a weaker shortwave can be seen pushing southeast of the local area, leaving more zonal flow aloft for today. Surface high pressure is influencing eastern KS, and clear skies and light winds have allowed us to reach crossover temperatures from yesterday with fog observed in parts of east central KS. So far fog has been on the patchy side, though visibility could quickly drop to a half mile or less in spots, particularly low-lying places and those spots that saw more rain recently. HREF probs for half mile or less show a decent signal for dense fog for a few hours around sunrise in eastern KS. Will continue to monitor obs and webcams to determine the need for a Dense Fog Advisory this morning if those lower visibilities indeed become more widespread. Forecast soundings show fog mixing out around 14z, at which point visibility should improve.

As mentioned previously, the main challenge with the forecast becomes timing and location of the greatest rain chances. CAMs are not excited about developing storms along the frontal boundary in southern Nebraska this evening, the 06z runs even less so than the 00z. Even if something isolated were to develop as 00z runs indicate, the instability axis is fairly narrow and mainly west of the area with a less favorable environment further east in terms of both instability and shear. Would think storms would have a harder time maintaining themselves into our area with that setup, plus there isn't a lot of forcing to support maintenance. The frontal boundary sags south through the day Saturday and would provide a better source of lift for thunderstorms. Assuming we don't have much in the way of rain or cloud cover into Saturday morning, we would also have better instability with MLCAPE increasing to 3000-4000 J/kg by late afternoon alongside deep-layer shear around 40 kts. This could support a few strong or severe storms with damaging wind and small hail being the main hazards into the evening. Pwat around 2" could lead to brief heavy downpours as well, though widespread flooding is not anticipated with storms looking to be more scattered. It is worth noting that recent models seem to be placing the front further south, which would favor southern portions of the area during this time frame.

As a deep upper low comes onshore of the Pacific Northwest and the upper ridge strengthens slightly just to our south, the sfc front looks to lift back north as a warm front Sunday into Monday. This leads to southwesterly flow developing aloft and warming temperatures. While some rain chances linger into Sunday, a general drying and clearing trend is expected from south to north through the day. Most of Monday looks dry until the evening hours when storms develop along the front, which at this time looks to be placed from southeastern NE through north central KS with the sfc low located in southwest KS into the OK/TX panhandles. With the aforementioned upper ridge strengthening over the southeastern US by Tuesday, this slows the southward movement of the sfc front which may stall over the region on Tuesday. This keeps likely PoPs over much of the area during the day. Tuesday onward is also when we begin to see large spreads in temperatures, which will be tied to the exact location of the front as well as clouds and rain. The front may again move back north on Wednesday depending on the strength of the upper ridge. Uncertainty in the evolution of that pattern leads to lower confidence in the later part of the forecast period in terms of precipitation and temperatures, with at least some rain chances persisting through mid-week.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 549 AM CDT Fri Sep 11 2026

Fog has led to LIFR conditions at TOP/FOE with vsby bouncing between a half and quarter mile. MHK is on the western edge of where the bulk of fog can be seen on satellite, and MVFR conditions should hold there. Fog should mix out and lift to stratus briefly around 14-15z with VFR conditions returning by late morning and continuing the rest of the period. Winds pick up from the south but remain light.

TOP WATCHES/WARNINGS/ADVISORIES

None.