FXUS65 KTFX 020532 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1132 PM MDT Sat Jun 1 2024 .Aviation Section Updated... .SYNOPSIS... A few light rain showers and general thunderstorms late this afternoon into the early evening hours across Southwest and Central Montana. Near normal temperatures continue through this weekend into early next week with our next weather system moving into the region Monday bringing chances of precipitation Monday and Tuesday and strong winds through Wednesday. Above normal temperatures and drier conditions return for later next week. && .Update... Evening update has been published, with only minor adjustments made to overnight lows and PoPs to account for recent trends and latest guidance. Otherwise the on-going forecast is performing well. Scattered showers and isolated thunderstorms continue to lift northeast from Idaho/Western Montana and across Southwest and into Central Montana this evening. Main impact this evening from these showers and thunderstorms has and will continue to be gusty and erratic winds of between 30 to 50 mph. - Moldan && .AVIATION... 02/06Z TAF Period VFR conditions with mid to high level clouds are expected to prevail for all TAF sites through the period. Scattered showers with a few isolated thunderstorms are possible overnight, primarily affecting KLWT and KBZN. By 02/12Z, most of the showers will clear the area, giving a brief lull in precipitation before another round of showers moves back into southwestern Montana by 02/20Z. This second round will continue through at least 03/01Z with temporary periods of low-VFR/MVFR possible under heavier showers for KEKS and KWYS. -thor Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 550 PM MDT Sat Jun 1 2024/ Rest of today through tomorrow night...Near normal afternoon temperatures, with the exception of mountainous terrain as temperatures continue to be below normal with highs in the 50s, through the weekend with rain shower and a few non-severe thunderstorms this evening from Southwest Montana into Central Montana from a Bozeman to Lewistown line. Primary concerns today with any developed thunderstorms are lightning, gusty winds up to 40 mph, and a heavy downpour. A drier day is in store for tomorrow morning before our next impactful weather system arrives for tomorrow night into Monday. Monday through Wednesday...Upper level troughing is favored to move into the state from the Pacific Northwest and dig southward across Southwest and Central Montana bringing unsettled weather conditions. Strong winds and scattered rain showers and thunderstorms are in store for Monday afternoon and evening for along the Rocky Mountain Front, Central, and Southwest Montana. Probabilities of Wind Gusts greater than 55 mph from latest data from National Blend of Models 4.2 (NBM): Browning - 98% Cut Bank - 96% Great Falls - 60% Havre - 40% Upper level troughing is forecasted to move out of our region Tuesday night with upper level ridging building in for Wednesday with dry and windy conditions, especially along the Rocky Mountain Front Wednesday morning into the afternoon. We decided to extend the High Wind Watch to include portions of Cascade, Judith Basin, Fergus counties and along the Hi-Line through Wednesday afternoon. We also extended the timing for along the Rocky Mountain Front as mountain wave activity could occur. Winding down of strong winds reaching high wind criteria along the Rocky Mountain Front and the adjacent Hi-Plains region down into Central Montana, is likely (greater than 75 percent) Wednesday afternoon and evening as probabilities are still between 25 and 50 percent in a few higher terrain locations while elsewhere is below 25 percent. Thursday into next weekend...The Climate Prediction Center updated 6 to 10 day outlook for our region is favoring above normal temperatures (80%) and leaning below normal precipitation (45%) for this timeframe. Ensemble member guidance is currently in favor of upper level ridging to begin Thursday and continue through Saturday where uncertainty grows on whether upper level ridging continues or upper level troughing begins to move in for beyond Sunday. While upper level ridging is favored, a quick upper level shortwave can't be ruled out to bring some afternoon shower activity into Friday and Saturday. Webb && .PRELIMINARY POINT TEMPS/POPS... GTF 48 72 55 71 / 20 10 20 50 CTB 43 68 50 65 / 10 10 20 30 HLN 51 75 55 69 / 30 20 10 80 BZN 46 73 51 68 / 40 30 10 90 WYS 41 64 45 56 / 30 30 10 90 DLN 46 72 53 66 / 30 20 10 80 HVR 51 75 55 74 / 10 10 10 40 LWT 44 69 50 69 / 50 20 10 70 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Monday evening through Wednesday morning for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front. High Wind Watch from Tuesday morning through Wednesday morning for Bears Paw Mountains and Southern Blaine-Cascade County below 5000ft-Eastern Toole and Liberty-Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Northern Blaine County. && $$ http://www.weather.gov/greatfalls