Area Forecast Discussion
Issued by NWS Billings, MT
Issued by NWS Billings, MT
126 FXUS65 KBYZ 130312 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 912 PM MDT Fri Jul 12 2024 .UPDATE... Weak disturbance crossing the region this evening has been bringing isolated to scattered showers and thunderstorms over western and central zones. A stronger storm formed over Carter county earlier in the evening but has since slid east. Expect the convection to become more isolated in nature as we continue into the overnight hours, sliding east across southern portions of the area. Have updated PoPs to latest trends through the overnight. STP && .DISCUSSION... This afternoon through Sunday night... Hot conditions will continue through the weekend. Relief from the heat arrives for Sunday night into Monday. This is the hottest period for the northern Rockies, and as such the record highs are pretty tough to beat. At this time no record high temperatures are forecast for out area. That doesn`t mean you should take the heat lightly though, a heat advisory will remain in place through the weekend. Check out our social media page for tips on staying heat safe. Flow aloft is generally zonal as Montana is at the apex of the strong ridge centered over the 4-corners. As such there are weak disturbances crossing the area that are capable of producing scattered mountain thunderstorms in the afternoon/evening hours, becoming more isolated over the lower elevations as they move to the east. Even the overnight hours are not immune to a few areas with isolated convection as occurred last night. Expect this convective potential to continue for the next several days, with wind gusts to 50 mph being the main threat. This afternoon there is a marginal risk for a severe thunderstorm along the eastern state line. This is in an area of low level convergence, weak jet level divergence aloft, and plains moisture interacting with drier air to the west. A stronger wind gust to 60 mph would be the primary threat with any storms in this area. The latency of the storms over Carter/Fallon counties looks short with models trending any storms quickly eastward into the Dakotas after development. Tomorrow will see enhanced fire weather conditions over areas west of Billings into the foothills. Winds gusting 20-30 mph with RH values dropping into the teens in the afternoon. Fuels are curing quickly in the current heatwave but at this time much of this area is in a moderate fire danger position for the mountains and foothills. The lower elevation grasses are getting close to becoming cured out (Wheatland down into Sweet Grass and Stillwater counties). The Hot/Dry/Windy Index shows a 30 to 50 percent probability for reaching the 90th percentile conditions for Saturday over the west. Looking at the Fosberg index (combining RH and Winds) from the HREF shows the higher values generally in the areas of moderate fire danger and west of the area. Given the the forecast fire values and placement combined with the current fuels state will hold off on fire highlites for now. That said please be very careful with anything that could spark a fire this weekend. ...SAT JULY 13... SITE RECORD YEAR BIL 106 2005 LVM 103 2002 MLS 106 2005 SHR 107 2005 BHK 104 2002 ...SUN JULY 14... SITE RECORD YEAR BIL 108 2002 LVM 104 2000 MLS 110 2002 SHR 107 2002 BHK 107 2002 Chambers Monday through Thursday... Upper ridge retrogrades and builds up the west coast by late Sunday, opening the door for a cooler northwest flow pattern to set up over the area Sunday night through Tuesday. Temperatures drop into the upper 80s to lower 90s for Monday and Tuesday next week. The chances for precipitation aren`t terribly high despite the influx of cooler air and northerly winds to the area, with the best chances (20-40%) residing along the southern border zones. Trof shifts east on Wednesday, replaced by a building ridge. This will bring a return to hot and dry Summer conditions for the mid to late week period (highs 88-98). Chambers && .AVIATION... Scattered light showers and isolated thunderstorms are expected to develop late afternoon. This convection will spread eastward off the mountains and become more isolated into the evening, but will likely continue into the overnight hours along the southern border counties. Another area of convection is expected along the eastern state line around 21-22z. This activity will be stronger than that further west, but will not reside over SE Montana for very long as it will shift quickly into the Dakotas. Locally strong wind gusts will be the main threat with any storms through tonight with MVFR visibility near precipitation areas. Chambers && .PRELIMINARY POINT TEMP/POPS... Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 065/099 065/099 065/092 064/092 063/095 064/097 065/097 21/U 11/B 11/U 12/T 11/U 11/U 01/U LVM 056/098 058/096 058/092 058/091 056/093 057/094 058/094 31/H 01/B 12/T 12/T 11/U 01/U 11/U HDN 063/100 061/099 063/093 060/093 060/095 061/097 062/098 20/U 10/H 11/U 12/T 11/U 10/U 11/U MLS 066/095 065/099 065/090 064/090 063/092 064/094 065/095 11/U 10/U 10/U 11/U 11/U 10/U 10/U 4BQ 067/097 067/100 068/092 064/090 064/091 064/094 065/096 21/U 10/U 11/U 12/T 11/U 11/U 10/U BHK 062/093 062/098 061/087 058/087 058/088 060/091 061/093 12/W 21/U 10/U 12/T 21/U 11/U 11/U SHR 061/097 061/099 062/092 059/089 056/092 059/094 060/094 20/U 11/B 12/T 23/T 11/U 11/U 01/B && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...Heat Advisory in effect until 9 PM MDT Sunday FOR ZONES 29>34-36-37-40-42-56>58-63>66-138-139-141-169-170-172-173-228-235. Red Flag Warning in effect from 2 PM Saturday to midnight MDT Saturday night FOR ZONE 117. WY...Heat Advisory in effect until 9 PM MDT Sunday FOR ZONE 199. && $$ weather.gov/billings