155 FXUS63 KARX 050835 AFDARX Area Forecast Discussion National Weather Service La Crosse WI 335 AM CDT Tue May 5 2020 .SHORT TERM...(Today and tonight) Issued at 334 AM CDT Tue May 5 2020 At 3 AM, a dry easterly flow was continuing to bring very dry air into the area. Dew points across much of the area ranged from the mid-20s to mid-30s. This dry air was keeping the precipitation mainly south and west of the forecast area. Temperatures ranged from the upper 30s to mid-40s. Through tonight, a couple of shortwave troughs will move southeast across Iowa and central Illinois. BUFKIT soundings continue to show that a dry easterly flow along and north of Interstate 90 will keep the precipitation mainly across northeast Iowa and southwest Wisconsin. Due to this dry air, there is still some concern that these rain chances may be still too far north. Rainfall amounts will up to two tenths of an inch in our far south. High temperatures will be around 50 south of Interstate 90 and in the mid and upper 50s elsewhere. Low temperatures for Wednesday morning will range from the mid 30s to lower 40s. .LONG TERM...(Wednesday through Monday) Issued at 334 AM CDT Tue May 5 2020 On Wednesday afternoon, there will be very steep 900-700 mb lapse rates and surface-based CAPES up to 500 J/kg. The GFS continues to have a deeper layer of low-level moisture than the NAM, ECMWF, and Canadian. Due to this, kept a small chance of showers along and west of the Mississippi River. On Thursday and Friday nights, the combination of low dew points, mainly clear skies, and light winds will provide good nights for radiational cooling. In addition, the ECMWF standardized 850 mb temperatures anomalies will be running 1 to 2 standard deviations below normal. Freezes will be possible in central and north- central Wisconsin and frost elsewhere. On Friday afternoon, relative humidities will fall into the lower and mid-20s and northwest winds could potentially gust into the 20 to 30 mph range. These conditions could result in critical fire weather conditions. Rain then returns to the forecast from Saturday night into Sunday evening as a shortwave trough moves southeast out of the Northern Plains. Steep low level lapse rates in the wake of this system may result in the potential for wind gusts up to 40 mph on Sunday. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1030 PM CDT Mon May 4 2020 Cigs: High to mid clouds will continue to push in from the west tonight, lowering Tue morning but looking to hold VFR through the forecast period. WX/vsby: area of showers sitting off to the west across southwest MN/northern IA, sparked by an upper level shortwave trough. The trough is progged to drop southeast tonight/Tue, mostly holding just to the west. Meso model trends suggest some potential for -shra at KRST while KLSE likely stays dry. Accums look minimal and there may not be any vsby impacts with any of the showers that reach this far east. That said, mesos trending just a bit more west of this activity, and will lean the forecast that way. Wind: mostly east/northeast into Tue morning, then likely becoming more variable. Going to hold northeast for now, but expect some fluctuations with weak pressure gradient in the area. && .FIRE WEATHER... Issued at 334 AM CDT Tue May 5 2020 On Friday afternoon, relative humidities will fall into the lower and mid-20s and northwest winds could potentially gust into the 20 to 30 mph range. These conditions could result in critical fire weather conditions. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...Boyne LONG TERM...Boyne AVIATION...Rieck FIRE WEATHER...Boyne