A large area of low pressure that covered the Southern Plains interacted with Canadian High Pressure to cause widespread light freezing rain and freezing drizzle that was occasionally mixed with sleet. Although most areas only received a light glazing, there were exceptions.
Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 ICT wrote it up.
A large area of low pressure that covered the Southern Plains interacted with Canadian High Pressure to cause widespread light freezing rain and freezing drizzle that was occasionally mixed with sleet. Although most areas only received a light glazing, there were exceptions. Nearly 1/4 inch of glaze was reported in Marion (0.20 inch) while Newton received 1 inch of sleet.
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 Wichita, KS wrote its last area forecast discussion before the first event at Feb 21, 5:52 PM CST, 2 hours 31 minutes earlier.
Area Forecast Discussion National Weather Service Wichita KS 552 PM CST Wed Feb 21 2018 .SYNOPSIS... Issued at 300 PM CST Wed Feb 21 2018 A unique synoptic setup across the middle and western CONUS has made way for an unusually challenging forecast for central, south central, and southeast Kansas over the next 24-48 hours. Expect multiple winter precipitation types across the area at various times over the next day or two. The over-arching message with this system is that, regardless of precipitation type that your specific location receives, the weather will very likely create hazardous travel conditions and other inconveniences across the region. A Winter Weather Advisory has taken effect as of the writing of this discussion as a mix of snow, sleet, and freezing rain is expected to begin across the area this afternoon/evening. This WWA is valid through mid-day Thursday. Please see the latest WWA for more details. && .SHORT TERM...(This evening through Friday night) Issued at 300 PM CST Wed Feb 21 2018 Kansas is currently wedged between a large area of high pressure to our north over the High Plains and low pressure to our south over Texas. A deep surge of cold air has ushered in sub-freezing surface temperatures over the entire western CONUS and is expected to continue to remain in place for the rest of the work week before finally lifting back northward and bringing some relief this weekend. These freezing temperatures will play a major role in the wintry precipitation over the next day or two. The main trough is currently situated in the southern Rockies in the Southwest U.S. This system is expected to send waves northeastward across the Southern Plains, the next round of which will bring precipitation into the area this evening and into Thursday. Models show increasing moisture flux divergence across the CWA along with 850mb moisture transport into the region from the south in association with southerly flow aloft. Though confidence is high regarding moisture availability, the main challenge of the forecast surrounds the type of precipitation that will fall to the ground. Model soundings, especially for central Kansas locations, seem to indicate that precipitation will likely begin as snow, with early period thermal profiles completely below the freezing mark all the way into the upper levels of the atmosphere. It looks like the largest combination of snow and sleet accumulations (generally between 1 and 2 inches) will likely occur in this area, though some ice accumulation up to a tenth of an inch is also possible in Central Kansas once the transition to freezing rain and a snow/freezing rain/sleet mix occurs later in the event around midnight. For locations further south in south central and southeast Kansas, however, thermal profiles indicate that warming aloft will likely produce a sufficient warm nose in the mid-levels to allow for a mix of sleet and freezing rain. Though some snow mixed in is possible early in the event, this is less likely than in central Kansas and confidence is higher that it will be more of a mixed phase precipitation event in south central and southeast Kansas. It is expected that, for the most part, south central and southeast Kansas will likely transition to nearly all freezing rain with some occasional sleet mixed in during the very early morning hours on Thursday. This will lend itself to ice accumulations of various amounts across much of the CWA, though the largest ice accumulations of generally between one and two tenths of an inch are expected in south central and southeast Kansas along and east/southeast of a line stretching from Marion, McPherson, and Reno counties. Note that this area also includes the Wichita metro. This area will serve as a transition zone in precipitation type meaning that they can expect some combination of snow, sleet and ice accumulation from freezing rain, though the ice accumulation is probably of greatest concern at this point for the metro since its overnight and early morning timing will likely create issues for the morning commute on Thursday morning. By Thursday morning around sunrise, the precipitation is expected to have eased off a bit and transitioned to more of a freezing drizzle across the entire CWA. As temperatures warm up above the freezing mark from southeast to northwest across the area, the freezing drizzle will transition to a chance of drizzle and rain throughout the day on Thursday before tapering off overnight Thursday night into Friday. By Friday morning, all precipitation should end across the area, though a slight chance of rain in far southeast Kansas cannot be ruled out during the afternoon with increasing low level moisture once again, though it appears that moisture availability will remain somewhat limited and the bulk should stay outside of the CWA. Temperatures are expected to warm up into the 40s and 50s on Friday, which should help melt any remaining accumulations that are already on the ground from the Wednesday evening through early Friday morning event. .LONG TERM...(Saturday through Wednesday) Issued at 300 PM CST Wed Feb 21 2018 Our next shot at precipitation will come during the day on Saturday ahead of the next shortwave to make its way across mid-America. Indications are, however, that a pocket of drier air situated over the CWA will limit precipitation amounts and the current thinking is that this will be more of a drizzle then transitioning to light rain. Not expecting much in the way of moisture accumulation, with rainfall accumulations up to three tenths of an inch in southeast Kansas with less expected elsewhere. Following this system, high pressure is expected to build into the region during the day on Sunday, which will dry things back out and keep the forecast dry through at least Tuesday. With the upper pattern becoming more zonal, expect milder temperatures and a gradual warming trend from Sunday into early next week, with highs into the low 60s by Tuesday. Early thinking is that the next trough should begin to make its way through the Central and Southern Plains by late in the extended period, though moisture availability looks fairly low at this point. Downslope flow should help maintain above normal highs again on Wednesday through the remainder of the extended forecast. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 535 PM CST Wed Feb 21 2018 A widespread wintry mix will continue to develop across the area this evening while spreading north and east across the area. Freezing rain, sleet and snow will be possible at times as the warm layer just above the surface slowly increases with time. The current forecast maintains a decreasing trend during the morning hours, although another period of light precipitaton may be possible later in the afternoon. && .FIRE WEATHER... Issued at 300 PM CST Wed Feb 21 2018 With multiple chances of precipitation in the forecast over the next several days, fire weather concerns will be minimal. Not expecting any major fire weather conditions throughout the forecast period. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 26 36 28 46 / 100 40 10 10 Hutchinson 24 34 25 44 / 100 30 10 0 Newton 24 35 27 44 / 100 30 10 0 ElDorado 25 36 29 45 / 100 40 10 10 Winfield-KWLD 27 38 29 48 / 100 40 10 10 Russell 20 32 23 43 / 90 30 10 0 Great Bend 20 33 23 43 / 80 20 10 0 Salina 24 34 25 43 / 100 40 10 0 McPherson 24 34 25 43 / 100 30 10 0 Coffeyville 30 43 32 51 / 90 60 50 20 Chanute 28 40 31 48 / 100 50 40 10 Iola 27 39 31 47 / 100 40 50 10 Parsons-KPPF 30 42 32 50 / 100 50 50 10 && .ICT WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon CST Thursday for KSZ032-033- 047>053-067>072-082-083-091>096-098>100. && SYNOPSIS...TAV SHORT TERM...TAV LONG TERM...TAV AVIATION...MWM FIRE WEATHER...TAV
Hazardous Weather Outlook National Weather Service Wichita KS 428 PM CST Wed Feb 21 2018 KSZ032-033-047>053-067>072-082-083-091>096-098>100-222230- Russell-Lincoln-Barton-Ellsworth-Saline-Rice-McPherson-Marion-Chase- Reno-Harvey-Butler-Greenwood-Woodson-Allen-Kingman-Sedgwick-Harper- Sumner-Cowley-Elk-Wilson-Neosho-Chautauqua-Montgomery-Labette- 428 PM CST Wed Feb 21 2018 This hazardous weather outlook is for portions of Central Kansas, South Central Kansas and Southeast Kansas. .DAY ONE...Tonight A wintry mix of snow, freezing rain, and sleet will spread across the area this evening and continue throughout the night. Check the latest winter weather advisory for details. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Light freezing rain and drizzle will be ongoing Thursday morning and continue through much of the day before transitioning to drizzle/light rain and ending Thursday night. Check the latest winter weather advisory for details. Another round of wintry mix is expected in central Kansas Friday night through Saturday morning. While there is still some uncertainty on the details, initial estimates for ice accumulations are a tenth of an inch or less, with a dusting of snow and sleet possible. Thunderstorms are possible across Labette County Friday night. These are not expected to be severe. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated tonight. && For a graphical version of this information, see our webpage at: http://weather.gov/wichita/hwo/
The national radar mosaic for the moment the first event began.
5 winter weather, 1 sleet. Local standard time, as filed.
Freezing rain was starting to make roads slick. Among them was Highway 50.
Around 0.20 inch of ice had accumulated from freezing rain and sleet. Country roads were ice-covered county-wide.
Around 1/8 inch of glaze was reported in McPherson.
Around one tenth inch of glaze had made roads slick.
Country roads and side streets were covered but main roads primarily were wet with slushy spots.
Around 1/8 inch of ice accumulated in Wellington overnight.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kansas in 2018Every state in 2018This day in weather historyWarnings in Kansas, February 2018
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: 735121, 735124, 735125, 735126, 735122, 735123.