textproduct: Topeka

KEY MESSAGES

- Patchy river valley fog toward sunrise, then warm and dry today.

- Cold front Wednesday: gusty northwest winds, then the coldest air of the season with highs in the 40s and 50s Thursday and Friday and lows near or below freezing Friday and Saturday mornings.

- Low rain chances Saturday night into Sunday with a system tracking mainly south of the area.

DISCUSSION

Issued at 205 AM CST Tue Nov 10 2026

A broad ridge holds over the southern Plains early this morning with weak westerlies over Kansas, while the northern stream trough remains well north of the region and has shifted east over Manitoba and Ontario. At the surface, broad high pressure sits over the Kansas, Missouri, and Oklahoma border area, and a weak front has already brought a wind shift to north central Kansas with drier air behind it. Monday's highs reached the mid 70s, a few degrees above the NBM, as deep mixing dropped afternoon dewpoints into the upper 30s. That deep mixing is the main reason fog is even less of a concern than Monday morning, when it stayed confined to a few low spots. Crossover temps sit in the upper 30s to around 40 with temperatures still in the 40s, the VWP shows 20 to 25 kt between 925 and 850 mb keeping the boundary layer at least partially mixed, and the drier air arriving from the north cuts the moisture further. Forecast soundings carry little to no saturation depth, so at most patchy shallow fog forms in the river valleys toward sunrise.

A weak and diffuse boundary stalls near the I-70 corridor today, with light east to northeast winds early turning southerly as the day warms. It holds north central highs in the mid 60s while the rest of the area reaches the upper 60s to near 70. The NBM ran about 10 degrees too moist on afternoon dewpoints Monday, and with a similar airmass and deep mixing expected, dewpoints likely end up below guidance again this afternoon. A Pacific trough digs into the upper Mississippi Valley tonight, and the height falls and deepening northwest flow behind it drive a stronger cold front through the area around sunrise Wednesday, with northwest winds gusting 25 to 30 mph in the afternoon and highs in the low 60s. Mixing heights near 4500 ft behind the front support another round of deep mixing, so minimum RH likely falls into the upper 20s to mid 30s, but with 10 hour fuel moisture near 20 percent, above the range where fire danger climbs meaningfully, fire danger stays low despite the wind.

Behind the front the trough settles over the eastern CONUS with the ridge holding over the western CONUS, leaving Kansas in northwest flow as H85 temperatures fall from near 11 C Wednesday to near 1 C by Friday. Guidance has converged since last night, with the GEPS warm tail gone and the NBM now matching the ensemble median, so Friday is no longer a two scenario day. Highs hold in the low 50s Thursday and upper 40s Friday, and lows in the upper 20s to around 30 Friday and Saturday mornings bring frost and a freeze to most of the area after a growing season that has run long this fall without a hard freeze.

Ridging builds back aloft over the weekend with highs rebounding into the 50s, though the GEPS runs warmer than the ECMWF ensemble for Saturday and the speed of the warm up is now the open question. A southern stream system crosses Texas and the southern Plains Saturday night into Sunday, with roughly three quarters of the ensemble clusters tracking it south of the area, so rain chances stay low and fade Sunday night with dry weather to start next week.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1113 AM CST Tue Nov 10 2026

VFR expected this period. Shallow fog development tonight looks less likely due to high clouds moving over the area and with winds beginning to increase as a front comes through. Winds increase late tonight and early Wednesday and shift to the northwest behind the front. There could also be a brief period of marginal LLWS just prior to sunrise before sfc winds pick up.

TOP WATCHES/WARNINGS/ADVISORIES

None.