479 FXUS65 KBYZ 111605 AFDBYZ Area Forecast Discussion...Updated National Weather Service Billings MT 1005 AM MDT Thu Oct 11 2018 .UPDATE... Light overrunning precipitation continues across portions of the area this morning as an upper trough moves through the region. Light rain and snow will spread east through the day with only minor snow accumulations expected at the most. Highs in the 30s to 40s can be expected today. Have adjusted pops and winds to current trends. Otherwise, the rest of the forecast remains on track and the previous forecast discussion and an updated aviation discussion are below. STP && .SHORT TERM...valid for Tdy and Fri... Upper trof moving through the region is producing some light overrunning snowfall early this morning, mainly west of Rosebud County as of 3 am. Light precip will spread slowly east over time, and forcing looks to be strong enough for at least isolated showers to reach our eastern cwa by late morning, as precip tapers off in our west. An additional shortwave dropping out of Alberta and through eastern Montana could help generate some rain/snow showers across our central and eastern cwa this afternoon and early evening. Latest models do show some weak development under the colder air aloft associated with this Canadian energy. None of this will amount to much, maybe up to a half inch of accumulation where surface temps are cold enough, and we will see drying as subsidence spreads in from the NW this evening. Period of anticyclonic NW flow will bring lee side troffing and increased SW-W winds late tonight through Friday. Friday will also see a significant jump in temps and have pushed highs into the 60s for most of the cwa (much higher than the blended guidance per pre-frontal conditions and downslope winds). Should see gusts on the order of 45 mph at Livingston, Big Timber and Harlowton, with 30 mph gusts east of the foothills. This will be an abrupt change from the persistent east winds we've seen the past few days. Canadian cold front associated with a rather strong shortwave will bring a shift to gusty NW winds Friday night. Potential for rain to snow showers exists mainly after midnight and especially in our western areas. Would expect the onset of a little snow accumulation for our western mountains and north facing upslope areas (i.e. Red Lodge) before daybreak Saturday. Enjoy the roller coaster ride of temps the next few days. JKL .LONG TERM...valid for Sat...Sun...Mon...Tue...Wed... Cool and unsettled pattern persist into early portions of the extended forecast period, but dries out quickly following disturbance crossing the region Saturday. Unseasonably cool and unsettled northerly flow, will bring cloudy skies and snow showers Saturday. Temps will hang in the 30s to low 40s. Gusty northwest winds through the day will result in wind chills making it feel much colder. Precip will clear overnight, and a 1036mb surface high will allow temperatures to fall into the teens and lower 20s in most locations, with single digits in the high terrain. Sunday will continue to be cold with highs again in the 30s to lower 40s. Conditions will dry out through the day, with only a few isolated showers in the high terrain through the morning. A warmer and dry pattern will prevail through the remainder of the extended forecast period. Temps will return to upper 40s and low 50s on Monday and trend slowly upward to Highs in the 60s for Thursday, as upper level ridging is progged to finally shift slowly eastward into the CWA. AAG && .AVIATION... Stratus will be slow to lift this morning along with patchy fog. Expect Conditions to improve to MVFR or better by 17z in most locations. There will be areas of light snow across the area this morning, becoming more scattered in nature this afternoon. Mountain tops will be clear, while lower foothills and some pass locations remain obscured until mid afternoon. Westerly winds will increase this evening over western foothills with gusts to 40kts by midnight at LVM TAF location. Chambers && .PRELIMINARY POINT TEMP/POPS... Tdy Fri Sat Sun Mon Tue Wed ------------------------------------------------------- BIL 044 029/063 033/041 023/042 029/053 037/058 037/063 2/W 00/N 44/J 21/U 01/B 11/B 11/U LVM 045 031/061 030/037 020/040 025/050 033/057 033/061 2/W 00/N 45/W 20/U 01/B 11/B 11/U HDN 043 026/064 032/041 022/041 026/053 036/057 034/063 4/O 10/U 33/W 21/U 01/B 11/B 11/U MLS 041 027/062 032/039 021/040 026/052 036/055 034/061 6/S 10/B 22/J 11/U 01/B 21/B 10/U 4BQ 039 025/060 032/040 021/038 024/052 036/054 034/061 4/W 20/B 23/J 11/B 01/B 11/B 11/U BHK 040 023/057 030/035 018/037 021/048 033/050 030/057 2/W 30/B 12/J 10/U 01/B 21/B 00/U SHR 041 023/064 031/038 018/036 020/050 033/056 030/061 4/W 20/U 36/W 31/B 11/B 11/B 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings