958 FXUS63 KTOP 062311 AFDTOP Area Forecast Discussion National Weather Service Topeka KS 611 PM CDT Wed Apr 6 2022 ...Update to aviation forecast discussion... .DISCUSSION... Issued at 316 PM CDT Wed Apr 6 2022 Key Messages: - Scattered showers this afternoon - Very high to extreme fire danger today and Thursday - Windy conditions continue through Friday - Warming up this weekend The upper low continues to spin across the upper Mississippi Valley this afternoon with a 990mb surface low stacked underneath the upper low. The tightening pressure gradient has led to a windy day across the region with sustained northwest winds of 20-30mph and gusts of 30-40mph. Deep mixing and the lack of humidity recovery overnight allowed relative humidity values to drop quickly after sunrise with most locations reporting RH values in the upper teens to low 20s this afternoon. A shortwave dropping south around the western periphery of the upper low has increased cloud cover across northern Kansas with a slight increase in dewpoints and decrease in temperatures observed in this area. This trend will continue through this afternoon and into the evening, slowly decreasing the fire danger from north to south. The Red Flag Warning remains as is for this afternoon and evening. Scattered showers have also developed across southern Nebraska ahead of the wave as mid-level saturation and shallow instability increase. CAMs maintain these scattered showers through the forecast area this afternoon, so have kept some low POPs through sunset. Cooler air settles in on Thursday behind today's wave; highs will be about 10 degrees cooler than today. As a result, minimum relative humidity values will be slightly higher in 25-35 percent range across the area. This will suppress overall fire danger somewhat even with winds being just as strong as today. Guidance suggests a several hour window of RH values less than 30% across north central Kansas before another wave of clouds and increased low-level moisture moves in during the afternoon. After collaboration with fire partners, the Fire Weather Watch has been upgraded to a Red Flag Warning for Republic, Cloud, and Ottawa counties. Winds relax a bit on Friday although the combination of winds and low relative humidity will lead to elevated fire danger once again. The vertically stacked system finally pushes northeast Friday into Saturday allowing for upper ridging to build over the Plains. Winds will weaken Friday night into Saturday morning before strengthening again from the south Saturday afternoon as the pressure gradient tightens ahead of another digging trough across the western CONUS. Warmer temperatures are expected this weekend with highs reaching the mid 70s to near 80 degrees by Sunday. Uncertainty increases Sunday afternoon/evening into next week as ensemble and deterministic guidance vary on the evolution of the western trough. A surface trough pushes into the region late Sunday and remains draped across the area through Tuesday/Wednesday with southwest flow persisting ahead of the slowly advancing trough. Guidance differs on the location of this boundary; this is reflected by the NBM and GEFS temperature spreads which show a 15-20 degree difference in possible high temperatures for next week. With the boundary lingering across the area, chances for rain and thunderstorms persist from late Sunday through mid-week although day-to-day details remain unclear. The potential for severe thunderstorms will need to be monitored for this period as well; CIPS analogs are picking up on this potential even with the spread present in ensemble guidance. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 611 CDT Wed Apr 6 2022 VFR conditions will continue though winds will remain to be a problem through the bulk of this forecast. Winds back off a bit with diurnal processes but ramp up quickly after sunrise Thursday, mainly from 300-320. && .FIRE WEATHER... Issued at 323 PM CDT Wed Apr 6 2022 The Red Flag warning remains in effect through 8pm this evening for north central through portions of east central Kansas. Increasing clouds and slightly higher low-level moisture is building in from the north which will help to increase relative humidity through the rest of this afternoon and evening from south to north. While similar wind and moisture conditions are expected on Thursday, cooler temperatures will lead to slightly higher afternoon relative humidity vales, but afternoon RH values are forecast to fall into the 25-35% range, lowest across north central Kansas. After talking with fire partners, the combination of strong winds, dry fuels, and falling relative humidity will still support rapid fire growth, so the Fire Weather Watch has been upgraded to a Red Flag Warning for Republic, Cloud, and Ottawa counties from noon to 8pm Thursday. Elevated fire weather concerns will persist Friday into the weekend as dry and windy conditions continue. && .TOP WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 8 PM CDT this evening for KSZ008-009- 020>022-034>037-054-058-059. Wind Advisory until 8 PM CDT this evening for KSZ008-009-020>022- 034>037. Red Flag Warning from noon to 8 PM CDT Thursday for KSZ008-020- 034. Wind Advisory from 10 AM to 8 PM CDT Thursday for KSZ008-020-034. && $$ DISCUSSION...Flanagan AVIATION...65 FIRE WEATHER...Flanagan