338 FXUS65 KTFX 072346 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 545 PM MDT Fri Jun 7 2019 ...Update to Aviation... .SYNOPSIS... Cool and unsettled conditions persist through Saturday as an upper level low pressure system moves across the Northern Rockies and Montana. Rain and high elevation snow shower coverage will be greatest over southwest Montana today with scattered rain and mountain snow showers across most of north-central and southwest Montana Saturday. Drier conditions develop Sunday through much of next week with temperatures undergoing a warming trend. && .DISCUSSION... Rest of today through Saturday...A 700 mb cold front in vicinity of a Havre to Townsend to Dillon line will continue moving slowly eastward. Farther aloft, a mid- to upper-level trough continues to overspread our CWA from the west. Isolated to scattered rain showers and mountain snow showers will continue in vicinity of the 700 mb front. This front should exit north-central MT by around nightfall this evening and southwest MT by around daybreak Saturday. In addition, upslope rain showers and mountain snow showers persist along the Continental Divide. Highly-variable snow levels today (ranging from about 5,500 feet to 10,500 feet MSL and exhibiting a southeastward gradient) will lower tonight to about 5,000 to 6,000 feet CWA-wide. Up to several inches of snow may accumulate in our mountains through tonight, but no impactful snowfall is expected along any of our mountain passes. On Saturday, isolated to scattered rain showers and mountain snow showers persist as the aforementioned, eastward-moving trough and embedded disturbances traverse our region. Snow levels will range between 5,000 feet and 7,000 feet MSL and only minor additional snow accumulations are expected in our mountains. Thus, continue to see no need for any winter weather highlights. In general, rainfall totals through Saturday should be no more than 0.25". Of note, some areas will likely remain largely dry through Saturday given the isolated to scattered nature of precipitation. Temperatures remain below-normal. - Jaszka Sunday through Friday...No major forecast concerns throughout the timeframe outside of some breezy afternoon winds Sunday, and then precipitation chances Sunday/Monday/Thursday/Friday. H500 ridge will begin to build into the Northern Rockies and Northern High Plains by Sunday morning as the trough responsible for the cool and unsettled weekend lifts northeast towards the Hudson Bay. Lingering moisture over North Central Montana combined with northwest flow aloft and diurnal heating may allow for isolated to scattered showers and storms to develop during the late morning and persist through the evening hours Sunday, most notably over the mountains. In addition to the chance for some showers/storms on Sunday, gusty westerly surface winds of 20-30 mph are expected over the plains of North Central Montana given unidirectional low through mid-level flow, steep afternoon lapse rates, and H700 winds of 15- 30kts. The aforementioned ridge will continue to slide and build east through the day on Monday, but a fast moving wave rounding the the axis of the ridge over Southern Canada will dive southeast and across the region Monday afternoon/evening. This fast moving wave will help to spark off isolated to scattered showers across North Central and portions of Southwest Montana Monday afternoon and evening, with the best focus for precipitation once again being over the mountains. Temperatures will begin to moderate Monday and Tuesday, with highs climbing back above normal by Wednesday and remaining above normal through Friday. Quiet conditions are currently expected on Wednesday as the axis of the ridge moves overhead, with chances for precipitation returning to Southwest and Central Montana Thursday afternoon and into the day on Friday as the ridge is broken down by a shortwave dropping southeast from the Gulf of Alaska and across the Pacific Northwest. - Moldan && .AVIATION... Updated 545 PM MDT Fri Jun 7 2019 (00Z/Sat TAFs) Unseasonably deep and cold upper level trough currently over the Pacific Northwest moves eastward through Montana overnight and through the day on Saturday. Scattered to numerous rain and mainly mountain snow showers can be expected throughout the forecast period. VFR conditions should prevail for much of the period but periods of IFR/MVFR conditions can be expected at times in precipitation. Mountain obscurations likely through the entire forecast period. mpj && .PRELIMINARY POINT TEMPS/POPS... GTF 38 55 39 65 / 20 80 40 10 CTB 35 56 39 64 / 60 60 10 10 HLN 37 57 37 66 / 30 60 30 10 BZN 35 53 31 63 / 80 60 50 10 WEY 27 46 21 55 / 80 70 40 10 DLN 32 51 30 61 / 90 60 40 0 HVR 37 60 39 68 / 10 20 20 30 LWT 37 52 36 62 / 50 70 40 30 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls