180 FXUS63 KOAX 202034 AFDOAX Area Forecast Discussion National Weather Service Omaha/Valley NE 334 PM CDT Mon Apr 20 2020 ...Updated Forecast Discussion... .DISCUSSION... Issued at 256 PM CDT Mon Apr 20 2020 Our Monday afternoon has been a breezy one, but still plenty warm despite the gusty northwest winds across the region. Temperatures are in the upper 60s to lower 70s with winds gusting 30-40 mph at most locations. Humidity fell into the 17-28 percent range as expected, with additional decreases likely in the next few hours, and the resulting very high to extreme fire danger will persist through approximately 7 PM today. One interesting feature at the moment is the southwesterly extension of a short wave trough as the trough axis is moving across the forecast area this afternoon. Ahead of the trough axis have seen an increase in shallow cumulus cloud cover at the top of the mixed layer near 10k feet AGL. There are a few weak returns showing up on radar, but with the high cloud bases and RH around 20 percent it is very unlikely that precip will reach the surface. Behind the trough, subsidence is evident in WV imagery over SD and now moving into far northern NE. This has helped to increase wind gusts a bit to 40 kts or stronger. Northeast NE may experience a few of these stronger gusts in the late afternoon hours as well, but should see a general decrease in the intensity as we approach sunset. Surface high pressure builds over the region tonight with winds becoming light by morning. This will offer an efficient radiational cooling night once the winds die down, and have adjusted temperatures a bit cooler than most guidance especially in northeast NE. Tuesday will feature a return of light southerly flow and warm advection. Model guidance has been persistently much too cool and moist with surface T/Td predictions in similar days this spring so have gone several degrees warmer and a good amount drier than almost all guidance...leaning close to a RAP solution. This will result in another day with RH potentially at or below 20 percent, but winds will be light enough that there is no extreme fire danger expected. Rather, it will probably be a "Top 10 day" with widespread upper 60s to mid 70s, sunshine, and light winds. Expect a bit of low-level moisture return on Wednesday in advance of a weak cold front. This could be sufficient to spark showers and a few thunderstorms along the advancing front in the afternoon. At this time, instability appears minimal and surface convergence along the front is not clearly strong enough to initiate convection so strong storms are unlikely. A better chance of rain arrives late Thursday into early Friday with a strong storm system and attendant cold front. Once again, instability is weak and while thunderstorms are possible it appears unlikely to pose any organized severe threat at this time. A few areas may pick up a half inch of rain or so. Will have some cold advection behind this system with Fri/Sat/Sun highs in the 60s. For the most part, morning lows should be around 40, but IF high pressure and clear skies should time themselves to arrive around sunrise on any given morning could see temperatures approach freezing. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 1222 PM CDT Mon Apr 20 2020 VFR conditions expected through the TAF period. Expect wind gusts to 25 kts at OMA/LNK and 30 kts at OFK this afternoon, but gusts will end shortly after sunset. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...Red Flag Warning until 7 PM CDT this evening for NEZ011-012- 015>018-030>033-042. IA...None. && $$ DISCUSSION...Barjenbruch AVIATION...Barjenbruch