150 FXUS63 KTOP 200858 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 358 AM CDT Wed Mar 20 2019 .SHORT TERM...(Today and tonight) Issued at 345 AM CDT Wed Mar 20 2019 Today and Tonight, a positive tilt upper level trough extended from southwest IA, southwest into west central KS early this morning and will shift east across the CWA this morning. There was a small area of rain showers across north central KS that will diminish as they push southeast across the central and southeast counties of the CWA through the early morning hours. Isentropic downglide on the west side of the positive tilt H5 trough axis will cause skies to clear from west to east after sunrise and through the mid to late morning hours. Northwest winds of 10 to 20 MPH with some higher gusts will decrease through the late afternoon hours as a surface ridge of high pressure builds southeast across western NE into west central KS. Clear skies and light winds will allow overnight lows to drop into the lower to mid 30s. .LONG TERM...(Thursday through Tuesday) Issued at 345 AM CDT Wed Mar 20 2019 Thursday through Friday, an upper level trough will move onshore across central and southern CA coast and dig east-southeast across the desert southwest Thursday night before lifting northeast into the central and southern high Plains. The upper trough will fill as it lifts northeast into the high Plains. The center of a surface ridge of high pressure will move southeast across eastern KS on Thursday, then will shift east. Highs on Thursday will reach the mid to upper 50s. An upper level trough will dig southeast from east central Canada into New England and the mid Atlantic states on Friday. Stronger low-level CAA across the upper midwest will build a surface ridge southward just east of the MS river valley. This may keep high temperatures in the upper 50s to lower 60s even with a downstream H5 ridge amplifying across the Plains. The richer moisture advection will occur across west TX into western KS where ascent ahead of the H5 trough and isentropic lift will cause showers and isolated thunderstorms to develop through the afternoon hours of Friday. The rain will remain well west of the CWA Friday afternoon. Friday night through Monday night, the the negative tilt upper trough across the high Plains will lift northeast across KS on Saturday. The upper level trough will be filling as it lifts northeast into NE and IA Saturday night. The combination of DCVA ahead of the H5 trough axis and isentropic lift ahead of richer moisture return will cause showers and a few isolated elevated thunderstorms to develop across the CWA late Friday night into Saturday. The more widespread rainfall may shift northeast of the CWA by Saturday afternoon. A second upper level trough will move onshore across northern and central CA and dig east-southeast across the southwestern US early Sunday. This will cause 850mb and surface winds to back more to the south and transport richer gulf moisture northward. The resulting isentropic lift will cause a second round of showers and perhaps some isolated elevated thunderstorms to develop across eastern KS late Saturday night and continue through the day Sunday. The upper trough will amplify into a closed upper low across northwest OK by 12Z MON and then will move east along the KS and OK border through the day Monday. This will keep a steady light rain across the CWA from Sunday night through Monday. The 00Z run of ECMWF shows much colder air advecting southwest across NE which could cause the rain across NE to change over to snow on Monday. The ECMWF even has light rain changing to snow across the CWA Monday night with some minor accumulations of snow possible. The 00Z GFS solution tracks the upper low farther north and brings an end to the light rain after 00Z TUE before the stronger CAA develops. Highs Saturday will only reach the mid to upper 50s, with lower to mid 60s on Sunday. Monday will be colder with northeast winds, highs will only reach the upper 40s to mid 50s, though if the ECMWF forecast verifies then the northern counties will struggle to reach 40 degrees with lower to mid 40s elsewhere across the CWA. Tuesday through Wednesday, an upper level ridge across the western US will move east into the Plains on Wednesday. High temperatures on Tuesday will be in the 50s, with highs in the lower 60s on Wednesday. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1141 PM CDT Tue Mar 19 2019 Low-level moisture wrapping behind the surface front bringing IFR to LIFR cigs into the terminals, and the duration of these conditions are the main challenge for this forecast. Overall have not made huge changes to the trends to VFR through the period, and expect the greatest limitations to be rather short-lived based on upstream observations. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...Gargan AVIATION...65