917 FXUS65 KTFX 110537 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1140 PM MDT Sun Sep 10 2017 Aviation Section Updated .UPDATE... Evening update has been published. Main adjustment made was to drop low temperatures further across the cold prone valleys in Southwest Montana and along the Continental Divide. Winds within these valleys will become light and skies are expected to remain clear (with the exception of areas of smoke), giving way to ideal radiational cooling processes. Otherwise, the previous forecast remains on track, with the Red Flag Warning continuing for Fire Weather Zones 112/113/114/115/117. - Moldan && .SYNOPSIS... Breezy, dry, and warm conditions will continue through Tuesday. Wednesday brings a change in the weather pattern as a slow-moving cold front sweeps southward out of Canada. Southwest and north- central Montana will see a good chance of rain behind this front through Friday. Temperatures will be much cooler as well, with highs near 50 in many areas Friday. Temperatures will rebound into the lower 70s by Sunday. && .AVIATION... Updated 0540z. Patchy areas of mid/high level clouds will move over the region through 12z Monday...otherwise mostly clear skies are expected. Most areas will have VFR conditions...but areas of smoke could create IFR conditions with mountains obscured at times...mostly along the divide. Brusda && .FIRE WEATHER... Despite strong gusty winds over the plains today, humidity values have been a bit more marginal than expected. However, given how low fuel moistures are the Red Flag Warnings will continue for the Rocky Mountain Front and over the plains. After a disturbance passes across the area overnight tonight, very dry air will again filter into the region. West winds will once again increase behind this disturbance during the day Monday, resulting in yet one more day of critical fire weather conditions. Winds and humidity levels moderate Tuesday, resulting in elevated fire weather conditions with continued warm temperatures. Wednesday will represent the transition period in the dramatic shift in the weather pattern to wetter and cooler conditions Thursday and Friday. && .PREV DISCUSSION... /ISSUED 710 PM MDT Sun Sep 10 2017/ Tonight through Tuesday...The NBM has been pretty consistent showing a westerly flow in place through Tuesday over most of Montana. The atmosphere will be quite dry, and temperatures will remain well above normal through Tuesday. These conditions, together with gusty winds Monday, will warrant continued concern for the fire weather situation. Smoke from the many wildfires will also linger the next couple of days and may at times result in reduced visibility and low air quality. Britton Tuesday Night through Sunday...Main forecast concerns within the long term period is the threat for rain, below average temperatures, and even the possibility of the season's first mountain snowfall. Confidence continues to grow that a strong Pacific system will affect the Northern Rockies and Northern High Plains during the middle-to-late work week timeframe. This system is poised to bring a period of rain, brisk winds, and below-average temperatures to the region, which will mark a dramatic pattern shift away from the hot and dry conditions that North-central and Southwest Montana have experienced over the past couple of months. The transition begins on Wednesday morning as a cold front advances into North-central Montana. Scattered showers and thunderstorms appear likely across the southwest Wednesday afternoon. Areas of rain become more organized Wednesday night into Thursday as a longwave trough amplifies and digs through the PacNW. Operational and ensemble model solutions vary in the intensity of the trough. Hence, details in timing and extent of precipitation remain unfocused. A consensus solution favors Thursday into early Friday as the period of heaviest precipitation for N-central Montana. Widespread rainfall amounts of 0.75 to 1.5 inches are suggested near the middle of the QPF distributions, though higher amounts are possible. Rain should change to snow over the northern and central mountains Thursday night, with a few inches accumulation possible at elevations above 6500 feet. Friday will be chilly day to say the least, as temperatures struggle into the upper 30s across higher elevations to only the mid 50s for most plains/valley locations. Precipitation will gradually end late Friday night and into the early morning hours on Saturday. It should be noted that some locations across North-central Montana may see their coldest overnight temperatures since May by the end of the work week. Area gardeners should be prepared for the potential for frost by the end of the work week, especially if temperature guidance continues to trend downward. In addition, wind chill values across the higher elevations and within mountain valleys may fall into the teens above zero. These cold temperatures combined with falling precipitation, will lead to hazardous conditions for anyone recreating outdoors, especially those who are not properly dressed/prepared. - PN/Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 54 88 53 86 / 0 0 0 0 CTB 47 86 47 82 / 0 0 0 0 HLN 54 88 54 89 / 0 0 0 0 BZN 48 85 49 87 / 0 0 0 0 WEY 32 77 37 77 / 20 0 0 0 DLN 47 83 50 84 / 0 0 0 10 HVR 49 89 48 87 / 0 0 0 0 LWT 51 86 52 86 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 9 PM MDT Monday Central and Eastern Lewis and Clark National Forest Areas...Chouteau and Fergus Counties... Eastern Glacier/Toole/Central/Eastern Pondera/Liberty...Hill and Blaine Counties...Lewis and Clark National Forest Rocky Mountain District-Rocky Mountain Front. && $$ weather.gov/greatfalls