907 FXUS63 KTOP 021810 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1210 PM CST Sat Mar 2 2019 ...Update to aviation forecast discussion... .SHORT TERM...(Today through Sunday) Issued at 357 AM CST Sat Mar 2 2019 Surface ridge axis was over the Missouri river early this morning with plenty of mainly mid and high cloud over the central Plains downstream of a shortwave trough off the California coast. Regional radar returns are increasing as a weak wave approaches resulting in modest mid-level warm air advection. This setup continues into midday and moisture depths may increase enough in far northern locations of the local area for some light snow to fall early today with low-level east to northeast winds keeping the lower layers dry. Much more widespread and impactful snowfall is expected tonight into early Sunday as the California wave quickly passes through. There continues to be some variability in the details of amounts and timing, though confidence in a few to several inches of snow falling in increasing low-level winds is high. The most likely area of heavier amounts remains in the southwestern half of the local area where stronger frontogenesis and a less statically- stable layer exists. Ageostrophic response is fairly strong and SREF means continue to show some higher rates possible and support the notion of much of the snow accumulating over the 6-10 hour window. Increasing and deep cold-air advection in the later portions of Saturday night into Sunday via a 1050 mb high building southeast into the northern Rockies and cyclogenesis to the southeast will support high snow-to-liquid ratios with time and surface temps in 10-23 degree range in combination with 925mb winds in the 25-30 knot range will support blowing and drifting snow in the middle to perhaps well past the end of the precipitation into Sunday afternoon. Expected snowfall with the wind has pushed the Winter Storm Warning on southeast across much of east central Kansas, and nearly-steady temps to combine with the wind to bring Advisory-needing wind chills to much of the north and northwest. Record lowest-maximum temps for Sunday will be approached depending on specific values near midnight tonight. .LONG TERM...(Sunday night through Friday) Issued at 357 AM CST Sat Mar 2 2019 By Sunday night, expansive surface high pressure will continue to spread across the central U.S., with northwesterly winds continuing to usher much colder air into the region. The combination of these northwesterly winds and mostly clear skies will result in decent radiational cooling, causing overnight low temperatures to plummet into the negative single digits across the entire outlook area. With sustained northwesterly winds of 5-10 mph, wind chill values look to plunge into the -12 to -24 degree range. As a result, anticipate the need for Wind Chill headlines eventually for this time period. A brief stretch of drier conditions is expected through the first half of next week as surface high pressure remains anchored over the central U.S. Persistent northerly winds will keep temperatures on the colder side with Monday highs in the teens and Tuesday highs into the 20s. As a mid-level ridge begins to build into the central U.S. by mid-week, it will help to shift the high pressure further east, thus causing winds to become more southerly. This shift to southerly winds by Wednesday will help to boost high temperatures into the 30s. The weather pattern looks to become more unsettled by late week into the weekend as models show two embedded shortwave troughs skimming eastward across the central U.S. The first embedded shortwave may bring precipitation chances back into the area by Thursday into Friday with a deeper mid-level trough expected to bring additional precipitation chances over the weekend. There is still notable variability with the exact tracking, timing, and strength of these disturbances, however periods of a rain/snow mix may be possible as highs rise into the 30s/low 40s and overnight lows drop into the teens/20s. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1142 AM CST Sat Mar 2 2019 VFR conditions continue into the evening before conditions deteriorate into the 06Z time frame. Light snow develops from west to east. High confidence int the 06-12Z period seeing the most significant impacts across the area. While some of the snow expected will likely be heavy, still a little uncertain on where exact bands will be, so have opted to keep visibility to IFR levels. Could certainly see LIFR or VLIFR for periods. Right now going with -SN until smaller scale details come together and bands can be timed into the sites. Conditions improve fairly rapidly by the end of the period as snow exits the area to the east. && .CLIMATE... Issued at 357 AM CST Sat Mar 2 2019 Record Lowest Maximum Temperatures ---------------------------------- March 3 March 4 Topeka 16 (1978) 9 (1960) Concordia 12 (1960) 9 (1960) Record Minimum Temperatures -------------------------------- March 4 March 5 Topeka -7 (1978) -1 (1960) Concordia -7 (1978) 2 (1960) && .TOP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM this evening to noon CST Sunday for KSZ008>012-022>024-026-038>040. Wind Chill Advisory from 6 AM to noon CST Sunday for KSZ008>011- 020. Winter Storm Warning from 8 PM this evening to noon CST Sunday for KSZ020-021-034>037-054>056-058-059. && $$ SHORT TERM...65 LONG TERM...Hennecke AVIATION...Drake CLIMATE...65