556 FXUS65 KBYZ 271621 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 1021 AM MDT Mon Jul 27 2020 .UPDATE... Clear skies across the region with no updates. borsum && .DISCUSSION... Today through Tonight... It's been a rare cloudless night across the state of Montana as prominent upper ridging continues to build into the area, which combined with dry low-levels is helping to produce another cool night. Going into today, ridging will persist. Temperatures will rise back into the lower 90s, and relatively low dewpoints possibly dropping into the upper 30 will bring about humidities in the mid teens by the late afternoon. A weak shortwave will pass over the mountains late this afternoon and evening, with enough high-level moisture that there's a very low risk for an isolated thunderstorm. Winds will become southeast Monday night into Tuesday morning that will allow some moisture to move into the area. Vertz Tuesday through Sunday... The forecast will start out unsettled with a decent chance of wetting rains for most of southern Montana and northern Wyoming and especially southeast Montana. A upper low from the Great Basin will slowly work across the forecast area Tuesday and Wednesday. Precipitable water amounts will steadily rise with values reaching 1-1.5 inches by Wednesday. Convection should fire over the west Tuesday and then gradually spread east Tuesday night and Wednesday. Convection does not look terribly strong (nothing severe expected) but high PWATs and expected slow storm motion, should lead to areas of heavy rain. Locations painted for the heaviest rainfall at this time is southeast Montana, where up to 1.5 inches is possible for southern Rosebud into Powder River and Carter counties. The GEFS runs were also hitting the Bighorn mountains and the western foothills for over an inch of rain during the period. Very, very difficult to pin point exact rainfall amounts in convective forcing but it is looking more and more like areas that need rain will get it. Will just have to keep a close eye on the heavy rain threat, as rain rates should be high and may cause culverts to fill quickly streams to rise. High temperatures will be around 90 degrees on Tuesday (which is right around seasonal norms), but be held down Wednesday with clouds and showers around. Looks like the mid 80s will be the best that can be expected Wednesday. The system slides east Thursday and ensembles were consistent on building an amplified ridge into the northern Rockies Thursday into the weekend. The EC ensembles were more aggressive in building the ridge strength and keeping it strong this weekend. Will side with that solution and thus have dry weather with high temperatures reaching the mid 90s by this weekend. TWH && .AVIATION... VFR conditions will prevail over the next 24 hours. There's a very low risk for isolated thunderstorms over the Beartooth Mountains in the evening. Vertz && .PRELIMINARY POINT TEMP/POPS... Tdy Tue Wed Thu Fri Sat Sun ------------------------------------------------------- BIL 091 063/092 065/088 062/092 063/094 063/095 064/096 0/U 03/T 44/T 22/U 11/U 11/U 11/U LVM 091 056/090 056/088 055/092 055/094 056/094 056/095 0/U 15/T 45/T 22/T 21/U 11/U 11/U HDN 093 060/093 063/086 060/091 060/094 062/096 062/097 0/U 03/T 45/T 22/U 11/U 01/U 11/U MLS 090 060/095 065/083 062/089 062/092 063/092 065/095 0/U 02/T 55/T 42/T 21/U 11/U 11/U 4BQ 091 061/094 063/082 061/086 059/089 060/092 062/094 0/U 03/T 67/T 43/T 21/U 11/U 11/U BHK 087 056/091 061/083 059/088 059/089 059/090 059/091 0/U 01/U 35/T 42/T 22/U 11/U 11/U SHR 092 058/091 059/083 057/088 056/092 058/095 060/096 1/U 16/T 78/T 43/T 22/T 11/U 22/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings