Marine Weather and Tide Forecast for Chapman, KS

DISCUSSION
Issued at 143 PM CST Fri Nov 6 2026

The 19Z water vapor imagery showed several waves over North America, with the forecast area mainly under the influence of a shortwave ridge. Surface obs showed high pressure centered over the middle MO river valley. Clouds within the surface ridge have struggled to mix out causing temps to hang out in the 40s.

For tonight through Saturday, the forecast area is expected to remain between the northern stream and the track of storm systems to the north, while an upper low over AZ cuts off from the mean flow and remains south of the forecast area. So with no prospects for synoptic scale forcing, attention turns to the surface high and it's impacts to the sensible weather. First is the cloud cover. The latest RAP and RRFS continue to show a pretty good inversion remaining over the cool low level air and inhibiting mixing of the boundary layer. This should keep the stratus over the area and perhaps have it fill back in to the west this evening. There is a bit of a concern for some fog development across parts of north central KS where the clouds have managed to mix out. The last couple days have seen an axis of dense fog on the western edge of the surface ridge. If the stratus doesn't fill back in, am concerned radiational cooling will cause dense fog. For now have leaned towards the low clouds filling back in, but have also added a mention of patchy fog for the north central counties.

For Saturday the surface ridge should begin to break down and allow surface winds to become a little more southwesterly. This is expected to facilitate better mixing and erosion of the inversion and low clouds by the afternoon. With this highs should warm to around 60. There may be another chance for some patchy fog Saturday night into Sunday with skies clearing out. There may be a little more wind in the boundary layer but the RAP and RRFS both show surface RH values near 100 percent. So have included some patchy fog in the forecast, especially for the low lying areas that tend to decouple more easily.

The mean westerlies look to remain north of the forecast area for Sunday through Tuesday while the southern stream remains south of the area. With limited moisture and no obvious moisture advection, the forecast is for dry weather to continue with temps gradually trend warmer. The main question with the forecast is how the pattern changes mid to late week. Ensembles show increasing spread in potential outcomes by Thursday as the models struggle with an amplifying upper ridge and trough. According to the 00Z ensembles, roughly 25 percent of the runs supported a stronger more amplified upper trough over the Midwest that would support the 12Z GFS solution. So the NBM and forecast show moderate temps through the end of the workweek. However it is hard to ignore the 12Z ECMWF is trending more in line with the GFS. Even the 12Z AI-GFS is similar to the GFS and ECMWF with a closed upper low developing over the Ohio river valley with meridional flow setting up over the Great Plains. If this evening's guidance continues these trends, the forecast may be a little too warm for Thursday and Friday of next week.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
Issued at 1040 PM CST Fri Nov 6 2026

MVFR cigs remain in place at KTOP/KFOE while skies have cleared at KMHK. Given clearing, conditions are favorable for fog at KMHK, although uncertainty remains in how much VSBY will be reduced. Guidance has caught on to the narrow band of stratus and has it mixing out/shifting east of Topeka terminals by 12-14z. VFR conditions are then expected through the rest of the period.

TOP WATCHES/WARNINGS/ADVISORIES
None.