059 FXUS63 KTOP 281731 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1131 AM CST Thu Feb 28 2019 ...Update to aviation forecast discussion... .SHORT TERM...(Today and tonight) Issued at 320 AM CST Thu Feb 28 2019 A mid level wave was moving eastward across Nebraska and Kansas this morning. Clouds have spread northward ahead of the wave across eastern Kansas. Light snow or flurries was confined to far southeast Kansas and southwest Missouri where isentropic lift was occurring in the 280K-290K layer. Center of the arctic high was located over eastern Nebraska at 08Z. Temperatures in the single digits were common across north central and parts of northeast Kansas over the snowpack while temps in the teens were common across east central Kansas. The mid level wave will continue to move eastward across Nebraska and Kansas this morning with the trough axis expected to move east into Missouri by afternoon. CLouds this morning will gradually diminish through the mid morning through the afternoon hours. Little mixing is expected today with the high pressure remaining over the cwa. Have tended a little cooler than guidance, especially over the snowpack and have kept highs in the teens there to the upper 20s across east central Kansas. Weak embedded waves are expected to move eastward across Kansas tonight within the zonal mid level flow. This will bring an increase of clouds overnight. The surface high pressure will gradually moves eastward tonight with light southeast winds expected on the backside of the high across north central and eastern Kansas. Lows tonight will cool back into the teens to around 10. .LONG TERM...(Friday through Wednesday) Issued at 320 AM CST Thu Feb 28 2019 Shortwave passing to the north brings falling pressures to eastern Kansas and western Missouri Friday morning to midday for continued warming with at least decent insolation behind another shortwave to the east. Cold front pushes through in the early afternoon to late evening for a much colder Saturday. Focus then turns to the combination of shortwaves off the west coast that make their way east into the central Plains Saturday night into early Sunday. Have some concerns that models may not be handling this nearly-coincident pair well and there remain to be some timing differences, but overall guidance is in rather good agreement with moderate Q-vector convergence aloft leading to moderate frontogenesis under some modest negative equivalent potential vorticity to bring a several hour period of respectable precipitation. Cold-air advection ramps up again for rising snow ratios, and there are indications some of the stronger frontogenesis may occur in the dendritic growth zone. Although the pattern does not suggest a heavy snow event, amounts could approach Warning levels, and such headlines may be necessary when combined with sustained winds nearing 20 MPH for some blowing and drifting potential. Complicating matters, GFS and NAM both showing some mid-level dry air to overcome Saturday evening and some freezing drizzle and freezing rain could also result early. The CAA wil also keep surface temps in the 2 t0 15 F range during the daytime hours for wind chills consistently from -5 to -15. Surface winds should diminish significantly Sunday night into Monday but wind chills drop further as the surface ridge of Arctic origins builds in. GEFS and NAEFS means continue to bring 850 mb temperature and surface pressure levels into record levels with mid-level flow due south from the Arctic into the central Plains. Could see some record-setting cold temps, with minimums currently looking to be the most likely. Northwest winds Monday night into early Tuesday remain at least modest, influenced by another upper wave to the northeast and bring one more period of concerning-level wind chills. Conditions modify into the mid-week with upper ridging building into the Plains from the west. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1122 AM CST Thu Feb 28 2019 VFR stratus to hold through much of the afternoon over terminals. There is lesser certainty in the stratus deck at TOP/FOE clearing out with forecast soundings showing a thin layer of moisture remaining throughout the early evening. There is a slight chance coverage becomes broken again around 4 kft overnight, but will address again in next issuance. && .CLIMATE... Issued at 320 AM CST Thu Feb 28 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... NONE. && $$ SHORT TERM...53 LONG TERM...65 AVIATION...Prieto CLIMATE...65