688 FXUS63 KTOP 091754 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 1254 PM CDT Tue Oct 9 2018 ...Update to aviation forecast discussion... .SHORT TERM...(Today and tonight) Issued at 352 AM CDT Tue Oct 9 2018 Precipitation remains rather persistent across the eastern half of Kansas downstream of the upper wave rotating northeast over New Mexico early this morning. Convective elements across the local area are somewhat limited, mainly on the precip's eastern flank east of the inverted surface trough where some mixed-layer CAPE persists on southeast winds. Hourly precipitation rates per ground truth were again more limited than those of Monday PM in the more stable environment. Surface low objectively analyzed near Frederick, Oklahoma moves north across northeast Kansas this afternoon as the upper wave continues northeast into southwestern portions of the state. Most persistent precip should occur in western portions of the local area with more scattered though perhaps higher-rate activity in better instability in the east. Training of this heavier precip will likely bring the greatest flash flooding potential this afternoon into this evening until the cold front passes late tonight and drier air steadily filters in aloft late this evening onward. How far west the surface low tracks will play a large role in severe weather potential with southeast surface winds leading to strong veering wind profiles, especially in the 0-1 km level. The amount of instability is also uncertain with plenty of cloud in place over the retreating warm sector. Set-up supports at least some brief tornado potential in the afternoon hours with concern expected to wane by early evening as some stabilization occurs and surface winds veer. .LONG TERM...(Wednesday through Monday) Issued at 352 AM CDT Tue Oct 9 2018 Wednesday the upper trough will continue to move off to the northeast into Minnesota. At the surface high pressure along with cooler and drier air will move into the north central and northeast Kansas. The dry advection will continue through the day on Thursday as a center of high pressure builds southeast into Kansas. Wednesday will see highs in the 50s across the area. A cold morning is expected Thursday morning with lows in the lower to upper 30s. There is the potential for areas of frost early morning Thursday with clear skies and light to calm winds for much of north central and parts of northeast Kansas. Thursday will see highs again in the 50s with overnight lows generally around 40 Friday morning. Late Thursday night the chance for rain will increase with the approach of a mid level trough and large scale forcing across the central Plains. Mid level frontogenetic forcing near 700 mb increases over the area early friday. The system is progressive with precipitation coming to an end from west to east across the area Friday afternoon. However another system will move off of the Pacific and move northeast into the southern and central Plains for the weekend. The main longwave trough in the west will phase with a northern stream trough Sunday and move through the Plains Sunday night and Monday. The weekend system will bring a high chance of rainfall to the area good moisture flux, favorable jet dynamics and surface and 850 mb lows moving across northeast Oklahoma with axis of highest rainfall across east central and southeast Kansas. Dry weather is expected for next Monday as the upper trough moves east. && .AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon) Issued at 1247 PM CDT Tue Oct 9 2018 For the 18Z TAFs, frontal system with low pressure center should finally push through the area by the second half of the period. this will bring a veering wind shift progressively through the afternoon then winds will be from the west by this late evening at all sites as the cold front pushes east of the area. Do expect the greatest threat for TSRA over the KTOP/KFOE sites this afternoon, so have gone with VCTS due to uncertainty in actual development. CIGS are expected to be mostly MVFR for the period, but could see a period of IFR CIGS near the early morning time frame with colder air moving into the region. Thinking wind gusts will be minimal for the majority of the period as stronger colder air push lags the initial front. Not certain on VIS restrictions, but with generally low level dry air working into the area, expecting a low stratus situation. && .TOP WATCHES/WARNINGS/ADVISORIES... Flood Watch through Wednesday morning for KSZ008>012-020>024-026- 034>040-054>056-058-059. && $$ SHORT TERM...65 LONG TERM...53 AVIATION...Drake