Area Forecast Discussion
Issued by NWS Billings, MT
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Issued by NWS Billings, MT
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-- Discussion containing changed information from previous version are highlighted. --961 FXUS65 KBYZ 080859 AFDBYZ Area Forecast Discussion National Weather Service Billings MT 259 AM MDT Wed May 8 2024 .DISCUSSION...-- Changed Discussion --Today through Thursday night... Satellite imagery showed a drifting upper low over western South Dakota spinning waves of precipitation into Montana. The system is very slowly weakening and 850-700 mb winds are slowly decreasing as expected, though some gusts 50-60 mph are still possible in the western foothills. The remaining high wind warning is valid until 6 AM and this should work out abut right. We did replace the high wind warning at Judith Gap with a winter weather advisory earlier last evening as precip had changed over to snow and was creating visibility issues. We have also had some wet snow noted in the higher hills around Billings and Roundup. Accumulations should be limited as warmer air will be moving in from the northeast as it wraps around the upper low...with snow levels lifting about 1000 ft by sunrise. (ranging from 4750 in the SW Mtns to 6600 ft east). So almost all rain on the plains by mid morning...which is why the winter weather advisory for Judith Gap only goes to 6 AM this morning. The high winds will be done by morning, but look for wet and blustery conditions yet today into tonight as waves of energy and moisture rotate around the upper low into our region as it slowly drifts south. Upslope will also be in play on north facing slopes of the mountains and foothills. The winter storm warnings for the mountains are still in place until noon Thursday. The heaviest snowfall is expected today and tonight. The chance of a foot or more of snow on north facing slopes ranges from 75-95% above 6500 ft...and the chance of over two feet at a whopping 60%! Precipitation will begin to slowly wind down Thursday as the upper low opens up and moves into the central plains phasing with energy in the Great Basin for a double barreled trough. Precipitation is progged to linger over the southern portions of our CWA with PoPs ranging from 60% in the foothills to 30% on the plains by Thursday afternoon, then dwindling to less than 20 percent Thursday evening. Look for highs today ranging from 40s west to mid 50s east. We warm up to 50s west to lower 60s east on Thursday. Hydro Issues...areas over our central and eastern zones have received 1-3 inches of rainfall (more in some local spots). Some of the rivers are rising in response and will need to be monitored. The most notable is the Tongue River at Miles City which is currently at 6.25 ft and forecast to rise to 8 feet by 6 AM Thursday (flood stage is 10 ft). BT Friday through Wednesday... High pressure building into the region looks to bring warmer and drier conditions into the weekend, with highs in the 70s by Saturday, lasting into at least Monday. Confidence is high for temperatures into the 70s, with a greater than 70% chance of exceeding 70 degrees Saturday through Monday. Uncertainty with the overall pattern increases early next week as ensembles show varying solutions, either ridging or shortwaves dropping into the region from the northwest. Shortwaves would bring cooler and unsettled conditions with chances for showers and thunderstorms. STP-- End Changed Discussion --&& .AVIATION...-- Changed Discussion --A large storm system will continue to bring periods of rain to the lower elevations and snow to the mountains and immediate foothills through the day today. MVFR to IFR conditions can be expected at times. Mountain obscurations can be expected through the period due to snow. Gusty west and northwest winds will decrease into the morning hours, turning more north to northeast for most locations. STP-- End Changed Discussion --&& .PRELIMINARY POINT TEMP/POPS...-- Changed Discussion --Tdy Thu Fri Sat Sun Mon Tue ------------------------------------------------------- BIL 051 043/059 041/066 044/077 048/078 051/080 052/075 9/R 85/R 20/U 01/U 01/U 12/T 23/W LVM 046 038/054 035/064 039/072 043/075 046/075 046/072 9/O 86/R 10/U 00/U 01/U 12/W 23/W HDN 054 041/061 040/068 040/077 046/078 048/081 049/076 9/R 85/R 20/U 00/U 01/U 12/T 33/W MLS 055 041/063 042/068 044/076 048/078 050/080 051/075 5/R 42/R 10/U 01/U 01/U 11/U 22/W 4BQ 052 039/060 043/067 042/075 047/077 050/080 051/075 6/R 34/R 10/U 00/U 01/U 11/U 22/W BHK 054 038/063 040/067 042/074 045/075 047/078 048/073 4/R 22/R 10/U 01/U 01/U 01/U 22/W SHR 048 037/056 037/065 037/072 043/075 045/076 046/074 +/R 85/R 21/U 00/U 01/U 13/T 34/T-- End Changed Discussion --&& .BYZ WATCHES/WARNINGS/ADVISORIES... MT...High Wind Warning remains in effect until 6 AM MDT early this morning FOR ZONES 56-65-66-141-172-228. Winter Weather Advisory in effect until 6 AM MDT early this morning FOR ZONE 63. Winter Storm Warning remains in effect until noon MDT Thursday FOR ZONES 67-68-171. WY...Winter Storm Warning remains in effect until noon MDT Thursday FOR ZONE 198. && $$ weather.gov/billings