textproduct: Topeka

KEY MESSAGES

- Widespread rain (70-90% chance) is forecast for Thursday. Rain amounts could range from a half of an inch to one inch.

- The chance for snow Friday afternoon and Friday night have increased to between 40-50%. The model solutions have a more southerly track of the upper level trough. - Areas west of a line from Minneapolis Grove to Holton have a better chance (40-60%) of seeing travel impacts from accumulating snow of an inch or two.

DISCUSSION

Issued at 334 AM CST Wed Jan 7 2026

Early this morning, water vapor satellite imagery and upper air analysis showed an upper low off the northwest Mexican coast. An upper trough was digging southeast across the northeast Pacific ocean. An upper level trough was located across the eastern US. Zonal upper and mid level flow was noted across the Plains.

Today:

The H5 trough across the northeast Pacific will dig southeast onto the Pacific Northwest coast. The southern stream H5 low will move on shore across northwest Mexico, then get kicked northeast by the upstream H5 trough moving onshore across the Pacific Northwest. The H5 low over northern Mexico will become an open wave H5 trough and will shift northeast into far southern NM. A down stream H5 ridge will amplify across the lower and mid MS River Valley. Southwest mid level flow over the central Rockies will cause a lee trough to deepen across southeast CO/far eastern NM. The resulting southerly low-level flow across the Plains will increase the low-level WAA. As a result, highs this afternoon will reach the mid 60s across much of the southern and eastern counties of the CWA. North central KS and areas along the NE will see highs in the lower 60s. southerly winds will increase to 10 to 20 MPH with some gusts of 25 to 30 MPH during the afternoon hours. High clouds will increase through the afternoon hours.

Tonight through Thursday night:

The short and long range models solutions are in good agreement with the southern NM H5 trough lifting northeast across west TX into eastern KS by Thursday afternoon. Ahead of the H5 trough lifting northeast out of west TX, residual moisture will be advected northward into the eastern KS after 6Z THU. The resulting isentropic lift will cause a steady light rain to develop south to north across the CWA. As the H5 trough lifts northeast across western OK into eastern KS, DCVA ahead of the H5 trough axis will enhance the lift providing more moderate rainfall. Several short term models show MUCAPE increasing to 100 to 500 J/kg, so there may be a few elevated thunderstorms across east central KS during the mid morning hours into the mid afternoon hours. Forecast QPF will be around 1 inch across the southeast counties with much of the CWA receiving 0.6" up to 0.8" of QPF. The total rainfall will be over a 12 hour period, so no flooding is expected, plus the ground is very dry from the lack of rainfall over the past 30 days. The H5 trough across Pacific northwest will dig southeast into the four corners region Thursday night. The southern stream H5 trough will lift northeast into mid MS River valley by 6Z FRI. Any lingering showers should shift northeast of the CWA Thursday evening. A surface front will also push southeast across the CWA on Thursday. The front will pass southeast across east central KS during the afternoon hours. Highs northwest of the front across north central KS will only reach the mid to upper 40s. Highs ahead of the front southeast of the KS turnpike will reach the lower to mid 60s.

Friday through Saturday morning:

The extended range models are in fair agreement. The past several model runs have been showing a more southerly track of the H5 trough across OK/KS and the H5 trough filling a bit as it moves east across OK and KS Friday night. A more amplified upper trough will be digging southeast out of south central Canada into the upper Midwest. The GFS/ECMWF/Canadian models show the best 850mb-600mb frontogenetical forcing along the the I-70 corridor through the evening hours. The big question is how quick will the colder air advection occur for the rain-snow mix to change over to snow during the mid evening hours of Friday. If drier air can advect faster southward, then a transition to all snow may occur earlier in the evening due to web-bulb cooling. Due to the more southern track of the upper trough, the northern counties may not see as much QPF. The colder air may take longer to advect southward into central and east central KS where the better dynamics may occur.

Due to the more southern track of the H5 trough the highest probabilities from the LREF for 1" or more of snow extends from McPherson to MHK and ranges from 40 to 50 percent. The probabilities across the northern counties of the CWA have dropped to 25 to 30 percent of receiving 1 inch or more of snowfall. The probabilities of 1 inch or more of snow drop to under 5 percent southeast of I-35. Its tarting to look like the impacts from the snow Friday night will be limited with a dusting up to 1 inch of snow possible.

The wrap around snow should end Saturday morning. The H5 trough across the Plains will lift northeast into the mid MS River Valley and phase with a deeper H5 trough digging southeast out of the upper Midwest.

Saturday afternoon through Wednesday:

The phased H5 troughs will deepen across the Great Lakes. The stronger low-level CAA will be east of the CWA Saturday night into Sunday. Highs Saturday and Sunday will only reach the mid 30s across northeast KS with lower 40s across the southwest counties of the CWA.

Early next week the upper trough across the Great Lakes will shift east off the northeastern US coast by Monday. The northwest mid level flow across the plains will become more zonal by Monday and Tuesday. Look for highs to warm back into the upper 40s north to lower 50s south.

The ECMWF is showing a big pattern shift with a H5 ridge amplifying across the eastern Pacific northward into eastern AK. This may cause arctic air in northern Canada to advect southward as H5 troughs dig southeast across the northern Plains into the OH River Valley. By the end of next week, highs may not get above freezing and there may be chances of light snow with clipper type systems.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 522 AM CST Wed Jan 7 2026

Expect VFR conditions through the next 24 hours. The light rain should not reach the terminals until after 12Z THU. There will be an increase in high and mid level clouds through the night. South-southwest winds will increase to 8 to 12 KTS with some minor gusts possible during the afternoon hours.

CLIMATE

Issued at 150 PM CST Tue Jan 6 2026

January 7th Record High Forecast High Topeka 68 (1965) 64 Concordia 63 (2006) 61

TOP WATCHES/WARNINGS/ADVISORIES

None.