FXUS65 KBYZ 192334 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 534 PM MDT Tue May 19 2026 .KEY MESSAGES... - Weather system brings the chance of precipitation to the area Wednesday into Thursday (60 to 100 percent, greatest over south- central Montana and north-central Wyoming). - 50-90% chance of seeing at least 0.50 inches of liquid precipitation west of a line from Harlowton to Sheridan. Snow levels as low as 6 kft. High chance for greater than 6 inches of snow in the mountains. - Increasing temperatures starting Friday with 80s F Sunday and Monday. && .UPDATE... Modest diurnal instability has allowed for isolated light showers to develop across our north as of 530pm, from Harlowton to near Miles City, and some sprinkles have been observed in spots further south. Have adjusted pops/wx to account for this activity thru around sunset. JKL && .DISCUSSION... Today through Monday... A weather system will impact the region Wednesday and Thursday. It begins late Wednesday with the passage of a cold front bringing Pacific Moisture. Northeast winds will create favorable conditions for mountains and foothills locations. Cross sections indicate deep moisture and decent omega, further increasing precipitation potential. Precipitation chances of 80-100% for the mountains and foothills decrease to the east with locations such as Miles City and Baker having the lowest chances (60%). This system will also bring thunderstorm chances of 15-30% Wednesday and Thursday. Severe storms are not expected. Locations west of a line from Harlowton to Sheridan have a 40-80% chance of getting greater than 0.5 inches of precipitation with locations locations east of Rosebud County having a <20% chance. Snow levels are expected to be in the 6,000-7,000 ft range keeping snow accumulations in the mountains. The Beartooth/Absaroka Mountains have a 50-100% chance of getting greater than 6 inches of snowfall but generally a <20% chance for greater than 12 inches. The Bighorn Mountains have a 50-80% chance for getting greater than 6 inches of snowfall and 30-50% chance for greater than 12 inches over the highest peaks. The highest snowfall totals will occur on north and east facing slopes. Temperatures in the 60s and 70s F will cool into the 50s and 60s F Thursday. Friday through Sunday will see increasing heights leading to warming temperatures and dry conditions. Temperatures in the 60s F Friday increase into the 80s F Sunday and Monday. More uncertainty enters the forecast early next week as ensemble systems indicate the potential for troughing to impact the region bringing cooler temperatures and precipitation chances. Torgerson .AVIATION... Very light rain showers are lingering along a line from K3HT to KMLS this evening, little to no impacts are expected with these. Additional weak shower activity along the foothills west of KBIL is possible, though impacts are not expected. A cold front is forecast to move through the region Wednesday afternoon, bringing the chance of showers and weak thunderstorms. Impacts include gusty winds and brief downpours. Matos && .PRELIMINARY POINT TEMP/POPS... Wed Thu Fri Sat Sun Mon Tue ----------------------------------------------------------- BIL 042/069 043/056 039/070 044/079 050/084 053/088 053/082 14/T +8/W 00/U 00/U 10/U 01/U 11/B LVM 036/063 036/054 033/067 039/076 045/081 048/083 047/075 03/T +9/T 00/B 01/B 11/U 11/N 14/T HDN 036/071 041/057 036/070 040/079 046/084 049/088 050/083 11/B 89/W 10/U 00/U 10/U 01/U 11/B MLS 039/072 043/062 040/069 041/078 048/084 050/088 053/084 21/B 45/W 21/B 00/U 10/U 00/U 10/N 4BQ 039/071 042/060 039/067 041/076 047/083 050/088 054/084 00/B 26/T 41/B 00/U 00/U 00/U 10/B BHK 036/072 038/064 037/067 040/075 046/083 049/088 052/084 01/B 36/T 53/W 10/U 00/U 10/U 10/N SHR 031/066 036/050 032/065 035/074 040/081 043/086 045/081 01/B 3+/T 52/W 00/U 01/U 00/U 22/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings