350 FXUS63 KUNR 010901 AFDUNR Area Forecast Discussion For Western SD and Northeastern WY National Weather Service Rapid City SD 301 AM MDT Thu Aug 1 2019 .DISCUSSION...(Today Through Wednesday) Issued at 301 AM MDT Thu Aug 1 2019 Upper ridging is persisting across the central CONUS, with the main axis through the Dakotas. Southwest flow aloft is stretching across the the western CONUS into Wyoming and far western SD, bringing monsoonal moisture to the area. Showers are progged to spread across northeast Wyoming earlier in the morning, pushing into far western South Dakota by mid to late morning. As diurnal heating continues into the early afternoon, stronger thunderstorms will develop. The best chances continue to be across northeast Wyoming, the Black Hills area, and western South Dakota mainly south of Interstate 90. MLCAPE will generally be in the 1500-2000 J/kg range with shear in the 25-35kt range. This will result in some of stronger storms, and a few severe possible. Bigger concern remains the potential for heavy rainfall/flash flooding. Latest NAM is showing PWATs at 150- 200% of normal and forecast soundings with mean RH of +70%. Forecast hodographs indicate generally slow moving mean motion and right movers this afternoon and evening. Models are also indicating convection persisting into the overnight hours east of the Black Hills into central South Dakota. With the persistent threat for heavy rain/training storms into the early morning hours toward central South Dakota, will expand the Flash Flood Watch farther east to include Haakon, Jackson, and Bennett counties. Precip is expected to slide east of the CWA on Friday morning. Chances for storms will return Friday afternoon and evening as ridge ridging waves push through the region. A warmer and somewhat drier pattern is expected through the weekend. Temps Sunday will reach well into the 80s to lower 90s as a thermal ridge pushes through. Models are indicating slightly cooler and much wetter weather returning early next week. && .AVIATION...(For the 06Z TAFS Through 06Z Thursday Night) Issued At 1047 PM MDT Wed Jul 31 2019 Isolated to scattered showers, and a few thunderstorms, are possible over northeastern Wyoming, the Black Hills area, and southwestern South Dakota during the rest of the night. Areas of IFR CIGS are possible over parts of south central South Dakota between 10Z and 15Z on Thursday morning. Scattered showers and thunderstorms over northeastern Wyoming and far western South Dakota on Thursday morning will spread eastward over the rest of western South Dakota through the afternoon and into the evening. Some strong to severe thunderstorms are possible. Areas of MVFR conditions are possible with the stronger thunderstorms. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Flash Flood Watch from noon MDT today through late tonight for SDZ024>032-041>044-072>074. WY...Flash Flood Watch from noon MDT today through late tonight for WYZ054>058. && $$ DISCUSSION...13 AVIATION...10