A mix of snow, sleet and freezing rain developed in the early morning of December 29th and quickly become primarily freezing rain. Ice accumulations of one quarter inch or more were reported across the northern portions of northeast Kansas mainly north of Interstate 70 where air temperatures stayed just below freezing for much of the day.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TOP wrote it up.
A mix of snow, sleet and freezing rain developed in the early morning of December 29th and quickly become primarily freezing rain. Ice accumulations of one quarter inch or more were reported across the northern portions of northeast Kansas mainly north of Interstate 70 where air temperatures stayed just below freezing for much of the day. Impacts however were muted due to the air temperatures gradually rising above freezing through the evening.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Topeka, KS wrote its last area forecast discussion before the first event at Dec 29, 5:18 AM CST, 42 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Topeka KS 518 AM CST Tue Dec 29 2020 ...Update to aviation forecast discussion... .DISCUSSION... Issued at 338 AM CST Tue Dec 29 2020 Complex and low confidence forecast this morning due to marginal temps both at the surface and aloft which will determine precip types and amounts today. The latest sfc map shows high pressure across IL with elongated low pressure stretching from the lee of the Rockies into west Texas this morning. Important to note that sfc winds remain easterly as of early this morning which continues to advect drier air into the area which should only act to slow any warming for this morning as precip becomes more widespread. Axis of 850-700mb frontogenesis continues to help generate banded snowfall across northern KS into southern NE this morning. That forcing should shift northeast and be replaced by strong isentropic lift/thetae advection. This will produce more widespread precip including some shallow convection as noted by radar returns over southern KS. The forecast temperature profiles will gradually respond to the temperature/moisture advection with the warm nose expected to reach or exceed 3C from south to north this morning across the CWA. Given the dry airmass expect sfc temps to drop toward the wet bulb and as a result our forecast for hourly sfc temps is colder than all other guidance for this morning. All of this should lead to a progression of snow to sleet to freezing rain from south to north across the area this morning. The sfc wave will eventually develop northeast along the front and enhance a southwest to northeast band of moderate to heavy precip by afternoon across the CWA which will then translate northeast across the area into this evening. Main question is how fast will surface temps warm to above freezing since this will determine how much ice may accumulate on sfcs. As mentioned, the sfc map shows a dry easterly flow in place so will opt for a colder RAP solution which suggests that sfc temps should reach or exceed freezing for areas south of I-70 by around noon but may be slow to erode the modified polar air in place across areas to the north and northeast of Topeka. HREF ensembles and the FRAM model ice accumulation fcst suggests that some areas north of I-70 could see ice accumulation in excess of one quarter inch today. Given that the obs suggest a colder drier start than GFS/EC feel that this scenario could occur so have decided to issue a winter storm warning for ice amounts in excess of one quarter inch in those areas where it appears sfc temps may be slowest to warm to above freezing and where the warm nose may be most pronounced today. That said given precip intensity/convective component this morning there could be other areas that see a quick quarter inch of ice before warming so our message to everyone is that the weather will cause hazardous conditions/icy conditions this morning. All in all a complex forecast where just a degree or two will make a huge difference in potential impacts. The sfc wave and associated precip should exit the area from west to east tonight with mainly rain expected as air temps hover just above freezing north of I-70 to the 40s south. Attention then turns to what could be a stronger winter storm Thursday night and Friday as the southern energy of the trough gets kicked out by an upstream wave and lifts northeast in a negative tilt fashion. The trends of the track of the 500mb low take it into southeast Kansas/southwest MO. Unfortunately, the temperature profiles again look too warm aloft for just snow but instead suggest a mix of freezing rain, sleet and eventually some snow. Given the intensity of this system and the amount of moisture it has this storm could produce widespread hazardous conditions for ice, snow and wind across the eastern half of Kansas Thursday night into Friday. && .AVIATION...(For the 12Z TAFS through 12Z Wednesday morning) Issued at 505 AM CST Tue Dec 29 2020 MVFR conditions will deteriorate to IFR at times today due to increasing precipitation in the form of snow, sleet and freezing rain which will eventually change to all rain after 19z today. LLWS may also be an issue this afternoon with a strong LLJ atop a rather stable boundary layer. All precip should end by 2z with gradually improving conditions thereafter. && .TOP WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until midnight CST tonight for KSZ010>012- 023-024. Winter Weather Advisory until 3 PM CST this afternoon for KSZ021- 022-026-034-039-040. Winter Weather Advisory until midnight CST tonight for KSZ008- 009-020. Winter Weather Advisory until 1 PM CST this afternoon for KSZ035>038-054>056-058-059. && DISCUSSION...Omitt AVIATION...Omitt
Hazardous Weather Outlook National Weather Service Topeka KS 441 AM CST Tue Dec 29 2020 KSZ008>012-020>024-026-034>040-054>056-058-059-301045- Republic-Washington-Marshall-Nemaha-Brown-Cloud-Clay-Riley- Pottawatomie-Jackson-Jefferson-Ottawa-Dickinson-Geary-Morris- Wabaunsee-Shawnee-Douglas-Lyon-Osage-Franklin-Coffey-Anderson- 441 AM CST Tue Dec 29 2020 This hazardous weather outlook is for east central...north central and northeast Kansas. .DAY ONE...Today and Tonight. A mix of snow, sleet and freezing rain will impact much of the area this morning into early afternoon. The combination of snow and ice accumulations will make travel hazardous across the entire area this morning into this afternoon. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Another storm system could bring more significant snow and ice to eastern parts of Kansas late Thursday into Friday. Anyone with travel plans Thursday or Friday should stay alert for this potential winter storm. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed through tonight. && More detailed information can be accessed at... http://www.weather.gov/top/sitrep
The national radar mosaic for the moment the first event began.
5 winter storm. Local standard time, as filed.
COOP observer at Blaine, Kansas reported 0.38 inch of ice accumulation from freezing rain. No other impacts reported.
The public reported of around one quarter inch of ice on elevated surfaces in Seneca, Kansas. No other impacts were reported.
Brown County DOT reported ice build up on elevated surfaces of more than one quarter inch to around .40 in Hiawatha. A few sporadic power outages were also noted via social media.
Spotter reported around one quarter inch of ice on elevated surfaces at Clifton, Kansas. No other impacts reported.
Social media post showed ice accumulation of around 0.30 on tree limbs in Marysville. No other impacts were reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kansas in 2020Every state in 2020This day in weather historyWarnings in Kansas, December 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 927300, 927301, 927302, 927303, 927304.