Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
793 FXUS65 KBYZ 142032 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 232 PM MDT Sat Sep 14 2024 .DISCUSSION... Through Sunday night... West flow aloft and a well-mixed airmass were bringing gusty winds to areas near the western mountains and foothills, and breezy conditions to Fallon County. Temps were in the 70s, except a few locations in the far E had reached 80 degrees. Flow will become SW tonight before giving way to a NW-SE oriented upper ridge over the forecast area on Sunday. Ridge shifts N Sun. night giving way to diffluence aloft. Weak cold front pushes into the W Sun. night. Will have a mainly dry forecast through Sunday night. However, models showed a few showers over the Beartooths/Absarokas Sunday afternoon and Sunday night. Also a 20-30 kt low-level jet will bring a slight chance of thunderstorms to the far SE corner of MT late Sun. night when MLCAPES will be 500-1000 J/kg and Bulk Effective Shear will be 30-40 kt. Otherwise, wind gusts will decrease this evening, but will pick up again Sun. afternoon around KLVM and K6S0 due to easterly flow, and over the far E as ESE flow increases in this area. Airmass warms up for Sunday with highs reaching the upper 80s E and S of KBIL. NBM had a 50% chance of KSHR reaching 90 degrees and an 80% chance for areas in SE Sheridan County. RH`s will be in the teens and 20s and while there will be breezy areas, Fosberg indices remain low for Sunday. Will highlight conditions in the FWF. Gusty winds will continue in the E for Sun. night due to the low-level jet. Arthur Monday through Saturday... As an upper low moves into the Great Basin on Monday, diffluent southerly flow, along with energy and moisture begin moving into the area bringing increasing shower and thunderstorm chances for western areas. Central and eastern areas look to remain dry. The area of low pressure lifts north into the Northern Rockies, Tuesday into Tuesday night, bringing increasing shower and thunderstorm chances (40-80%), greatest over western areas, and lowest over the southeast. Latest NBM probabilities of 0.25 inches or more of rainfall from Monday through Tuesday night range from 80% over the west to 20% over the far southeast. Some snow accumulation looks possible in the mountains above 9,000 feet as well, mainly Tuesday night. As the low lifts north into Canada on Wednesday, cool and breezy conditions wrap back around into the area. Troughing over the western US will keep conditions cool and unsettled with low PoPs in the forecast through Saturday. High temperatures in the 70s west, to the 80s east on Monday and Tuesday, are forecast to lower into the 60s and 70s for the remainder of the long term. STP && .AVIATION... Look for widespread VFR over the next 24 hours, with periodic high clouds. Dry westerly flow aloft will back to the SW by early Sunday, with isolated showers/thunderstorms possible over the southwest mountains Sunday afternoon/evening. Winds at the surface will shift out of the east for Sunday. STP && .PRELIMINARY POINT TEMP/POPS... Sun Mon Tue Wed Thu Fri Sat ----------------------------------------------------------- BIL 050/084 053/082 055/076 051/071 049/071 049/070 045/064 00/U 01/B 47/W 52/W 22/W 34/W 44/W LVM 045/082 047/080 048/068 044/067 041/068 040/068 037/063 10/U 24/T 79/T 75/W 34/T 34/W 44/W HDN 046/088 050/084 052/081 049/075 047/073 047/073 044/063 00/U 00/B 35/W 52/W 21/B 34/W 53/W MLS 049/087 058/087 058/083 053/072 050/071 049/071 047/063 00/U 11/B 13/W 62/W 21/B 33/W 53/W 4BQ 049/089 058/090 057/086 052/075 050/073 050/072 046/062 00/U 10/U 12/W 51/U 11/B 33/W 43/W BHK 049/087 057/088 056/086 050/074 048/073 047/071 044/064 00/U 11/U 02/W 62/W 11/B 24/W 43/W SHR 044/089 051/087 049/081 044/075 043/073 042/071 041/062 00/U 00/B 23/W 31/B 12/W 35/W 54/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings