textproduct: Topeka

KEY MESSAGES

- Coldest air of the winter arrives Friday, lasting through at least Monday. Prolonged period of below zero wind chills expected, as low as -15 to -20 at times.

- Snow likely Friday night into early Sunday. Still some uncertainty in exact totals, but forecast amounts have slightly increased. Winter Storm Watch issued for parts of east-central Kansas, where highest totals are expected.

DISCUSSION

Issued at 239 PM CST Wed Jan 21 2026

Broad troughing remains in place across the eastern 2/3 of the CONUS, with one embedded shortwave over the Midwest pushing a weak cold front south towards our area. Ahead of the front, sunny skies and westerly downslope winds are again boosting temperatures into the upper 40s. Behind the front this evening, a brief period of gusty north winds are expected, followed by cooler but still near- average temperatures for tomorrow.

The more notable changes arrive late tomorrow night as a stronger cold front plunges southward. This front will be associated with a deep upper low dropping south over the Great Lakes, with very strong surface high pressure moving out of central Canada. Temperatures fall into the single digit or low teens by sunrise Friday, and struggle to rise much throughout the day. So may need a Cold Weather Advisory as early as Friday morning, as wind chills will near -15 degrees at least near the Nebraska border. Cold air will become more entrenched into Saturday and Sunday as strong high pressure remains in place to our north. Wind chills look to stay below zero through at least Monday, very likely (80-95%) as low as -15 to -20 at times. Low clouds will tend to keep the diurnal temperature range lower Saturday and Sunday, with lows around zero and highs in the single digits to low teens. Temperatures should begin to rebound some by next week as the upper low to our north weakens and shifts east some. However this trend may end up a bit slowed if snow cover can stick around a bit longer.

Speaking of snow, that remains the main uncertainty and focus of the forecast. There are still notable uncertainties with the exact depth/tilt of the trough, which will be key for where and how much snow falls. But overall, guidance has come into better agreement with the general evolution of the western trough, as a northern stream shortwave dropping southeast from Canada merges with an upper low moving east from California. This looks to result in two somewhat distinct phases to the snow, with perhaps a brief lull in between. The first phase occurs Friday evening into Saturday morning as broad frontogenesis develops across Kansas. Ascent looks weak, but enough for some bands of light snow to develop. Suspect some guidance is too wet during this period, given the weak ascent and some drier low-level air. However even with very light QPF, a very deep DGZ should help make for some high ratio snow, even conservatively somewhere around 15:1.

After a brief lull sometime Saturday as this initial isentropic ascent wanes, guidance has trended more aggressive with the second phase Saturday night. This would occur as the main shortwave shifts east and a more defined 850 mb low passes to our southeast. Given better ascent and northward moisture transport, this would be our best opportunity for a brief period of heavier snow, particularly closest to the 850 low across east-central KS. Will continue to watch how guidance trends for this period, as a stronger and more NW low (as depicted in ECMWF/EPS guidance but not as much GFS/GEFS) will tend to deliver higher snowfall amounts. Again, cold temperatures aloft and a deep DGZ will help increase snow ratios, especially if we can get some better vertical motion.

So where does all that leave us? Confidence is high in at least a light (1-4" between the two phases) snowfall across most of the area. Best chance for higher totals (4-7+") appears to be south of I-70 and towards east-central KS, again tied to the track of the main system Saturday night. Have thus issued a Winter Storm Watch for portions of east-central KS along/south of I-35. If trends continue and uncertainty decreases, could end up expanding this watch farther north/west. Still plenty of time to better resolve these details, as short-term guidance comes into view over the next couple days. Lastly, important to note the combination of the snow with the very cold wind chills, as this will be potentially hazardous for anyone caught outdoors for a prolonged period.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1112 AM CST Wed Jan 21 2026

West winds will increase to 10-15 kts with gusts up to 25 kts this afternoon ahead of a cold front. This front looks to arrive at the main TAF sites around 0-1z, shifting winds to the north around 7-10 kts, becoming light and variable after sunset. Conditions stay VFR, with increasing high clouds tomorrow morning.

TOP WATCHES/WARNINGS/ADVISORIES

Winter Storm Watch from Friday evening through late Saturday night for KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.