092 FXUS63 KTOP 010449 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1149 PM CDT Sat Aug 31 2019 ...Update to aviation forecast discussion... .SHORT TERM...(This evening through Sunday) Issued at 313 PM CDT Sat Aug 31 2019 A weak upper level trough was moving east across central KS into eastern KS early this afternoon. An MCV from this morning thunderstorm complex across western KS has already dug southeast across south central KS and will shift southeast into OK late this afternoon. A few elevated showers may be possible through the remainder of the afternoon across the southern and eastern counties of the CWA. MLCAPES are less than 50 J/KG, so I do not expect that there will be enough instability for any thunder this afternoon. Tonight through Sunday, expect skies to clear during the evening hours. Patchy fog and low stratus will develop across the CWA after 3 AM Sunday morning but will mix out after 10 AM Sunday. An upper level ridge across the southwestern US will expand east into the southern high Plains. Highs on Sunday will warm into the lower to mid 80s. .LONG TERM...(Sunday night through Saturday) Issued at 313 PM CDT Sat Aug 31 2019 Sunday night through Tuesday, the broad upper level ridge across the southwestern US will expand east across the southern Plains. Highs will warm into the upper 80s to lower 90s Monday and Tuesday. Tuesday night through Wednesday, an upper level trough will dig southeast from western Canada into the northern Plains on Tuesday, then east southeast across the upper midwest and Great Lake States. Low-level CAA across the northern Plains will cause a surface front to push southeast across NE into KS after 00Z WED. There may be enough ascent on the southern edge of the H5 trough along with surface convergence ahead of the front for scattered showers and thunderstorms Tuesday evening across the northern counties which will spread southeast across the CWA through the night. As the H5 trough shifts farther east and the front passes southeast of the CWa, the showers and thunderstorms should end by the mid morning hours across east central KS. Wednesday will be cooler as a surface ridge of high pressure builds southwest across eastern KS. Highs will on Wednesday will only reach the mid to upper 70s. Wednesday night through Saturday, the upper ridge across the southern Plains will gradually retrograde to the west and amplify through the end of the week. The front across OK will under go frontolysis on Friday and a lee trough across the southern Plains will deepen. The resulting low-level southerly flow across KS will begin to advect richer gulf moisture northward Friday into Saturday. An upper level trough will round the ridge axis and dig southeast across the Plains on Saturday night into Sunday. There will be a chance for showers and thunderstorms Saturday afternoon ahead of the approaching H5 trough and surface cold front. Highs Thursday and Friday will warm back into the lower to mid 80s. Highs may be cooler on Saturday depending on the speed of the surface front and cloud cover. Highs Saturday are forecasted to reach the mid 70s along the NE border to lower 80s across the far southern counties. && .AVIATION...(For the 06Z TAFS through 06Z Sunday night) Issued at 1141 PM CDT Sat Aug 31 2019 Some level of uncertainty in how widespread fog will be overnight remains. It appears low level stratus may be more common over points around KTOP/KFOE terminals and points east as a deck has been building over the general vicinity. Where skies remain clear deeper into the night over points near KMHK, it may be a better setup for radiational fog to form and last until mixing begins by early to mid morning. Still uncertain as to how thick fog will become so have been more optimistic near KTOP/KFOE terminals and a bit more pessimistic near KMHK. Wouldn't rule out possible IFR vis restrictions at some point especially near KMHK if stratus development doesn't develop that far west. && .TOP WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Gargan LONG TERM...Gargan AVIATION...Drake