090 FXUS65 KTFX 171908 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 105 PM MDT Fri May 17 2019 .UPDATE... Webcams and surface observations indicate accumulating snow along the Northern Rocky Mountain Front, including the Browning area. Although precipitation intensity will decrease at times this afternoon and evening, additional rounds of snow are expected overnight through at least Saturday morning. Thus, a Winter Weather Advisory is now in effect for the Northern Rocky Mountain Front through Saturday. This area under advisory may need to be expanded as rain changes to snow over a wider area. && ...Aviation Section Update... .SYNOPSIS... Spring storm system will bring widespread rain and mountain snow to the region today. Snow could mix with rain even down to the plains overnight and Saturday morning. Unsettled and cool conditions continue into next week. && .UPDATE 9am... North northeasterly flow and abundant moisture continue to support cooling temperatures and widespread precipitation. Thunderstorm activity will be expected in southwest Montana, this afternoon. Overnight, expect snow levels to drop to valley surface, allowing for a rain/snow mix into the morning hours. The previous shift left a solid forecast that is working well; therefore, there will be no changes made to their work, at this time. - Fogleman && .AVIATION... Updated 1200 PM MDT Fri May 17 2019 (17/18Z TAF) Aviation forecast focus is on widespread MVFR conditions with areas of IFR/LIFR, at times. Mountain obscurations are expected. Icing conditions will occur in cloud and in precip with freezing levels falling to 4000' MSL, overnight. Gusty winds will develop. Expect turbulence particularly near mountains. - Fogleman && .PREV DISCUSSION... /ISSUED 545 AM MDT Fri May 17 2019/ Upper level trough continues to move inland across the western USA bringing widespread precipitation and cool temperatures to Montana today and through the weekend. Biggest change with this forecast package is that snow levels and temperatures have been lowered so that there is now an increased chance for snow to mix with the rain at lower elevations tonight and Saturday morning, and again Saturday night into Sunday morning. At this time it appears that snow accumulations at lower elevations will be limited, but this is still an important consideration for travelers and Department of Transportation concerns. Latest models also appear to have moved the threat for heaviest precipitation eastward with most locations in the Great Falls CWA expecting generally one half to one inch of liquid equivalent precipitation for today through Saturday night. Sunday should see more scattered precipitation with lesser QPF amounts anticipated. Monday through Friday of next week should see cool and unsettled conditions predominate as broad upper level troughing persists over the western USA and Canada. Models keep scattered PoPs in the forecast for each day of this period, but at this time it appears that the best likelihood for another widespread precipitation event will be Tuesday into Wednesday. There should also be a slow warm up in high temperatures late in the week. mpj && .PRELIMINARY POINT TEMPS/POPS... GTF 48 37 45 33 / 100 100 90 20 CTB 44 34 44 31 / 100 90 90 30 HLN 54 38 50 35 / 100 90 80 30 BZN 58 37 51 32 / 100 100 90 20 WEY 50 30 47 27 / 90 100 70 40 DLN 55 37 53 35 / 100 100 40 20 HVR 48 35 47 31 / 100 100 90 20 LWT 48 32 39 28 / 90 100 100 50 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 6 PM MDT Saturday Northern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls