075 FXUS65 KTFX 242347 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 547 PM MDT Mon Apr 24 2017 .UPDATED AVIATION... .DISCUSSION... Tonight through Wednesday...Mostly sunny skies today across North-central Montana has produced weak instability. Weak surface convergence along a stationary front will help spawn additional rain showers and isolated thunderstorms this evening. Precipitation coverage more widespread overnight due to upslope low level flow and enhanced divergence aloft. This activity extends into southwest Montana as a shortwave trough moves from west to east broadly along I90. A winter weather advisory remains in effect for southern Gallatin county where up to 3 inches of snow are expected at lower elevations, with higher amounts in the mountains. Precipitation continues through mid-day Tuesday before tapering from west to east. A dry period follow Tuesday night with subsidence following the departing shortwave. The next, more significant push of moisture advances into the area on Wednesday, with widespread rain and mountain snow developing from west to east. PN Wednesday night through Monday...An unsettled weather pattern will continue to reside over the region into early next week. The precipitation is likely to become more widespread by late Wednesday through Friday. Total precipitation amounts for later this week are still expected to average between 0.30 and 0.60 inches for many areas, with some isolated higher amounts. The main concern will be during the overnight hours as snow levels lower to around 3500/4000 feet or so. Thus some snow is possible in the bigger cities at lower elevations later in the week. At this time most snow accumulations at lower elevations will be on grassy areas, but a few inches of snow are likely in the mountains each day. Afternoon temperatures will be below normal through the entire period, with Thursday/Friday being the coolest days. Brusda && .AVIATION... Updated 0000Z. Scattered showers and isolated thunderstorms will be found across central and northern Montana sites this evening...while widespread showers move into southern portions. MVFR to brief IFR conditions are possible with any showers this evening. More widespread shower activity is then expected during the overnight hours...with some lower elevation snow possible from 07z to 18z Tuesday. MVFR to IFR conditions are again possible with these showers. Tuesday afternoon will see shower activity become more scattered...with lower elevation snow ending...and some thunderstorms possible across the south. VFR to MVFR conditions can be expected Tuesday afternoon. Mountain obscuration is possible through much of the forecast period. Anglin && .PRELIMINARY POINT TEMPS/POPS... GTF 35 49 33 54 / 60 70 40 50 CTB 35 47 32 51 / 50 70 50 50 HLN 37 55 36 56 / 80 60 30 40 BZN 35 51 32 54 / 90 90 50 50 WEY 29 42 25 42 / 90 60 30 80 DLN 34 52 33 52 / 60 40 30 60 HVR 34 47 33 55 / 30 50 50 40 LWT 32 44 31 51 / 70 60 60 50 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon MDT Tuesday Gallatin. && $$ weather.gov/greatfalls