FXUS65 KTFX 022002 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 202 PM MDT Wed Oct 2 2024 .SYNOPSIS... Near to slightly below normal temperatures continue through Thursday, before warming up to above average temperatures Friday through mid next week. Breezy to gusty winds are possible Friday afternoon through Saturday morning, especially along the Rocky Mountain Front and the adjacent Plains. Along with winds, light precipitation is also possible during that time frame. && .DISCUSSION... Key Points: - Low chances for a few light rain showers along the Hi- Line/Northern Fergus County region through tonight. - A cold front and a quick moving upper-level shortwave bring breezy to gusty winds and elevated fire weather concerns to the region Friday P.M.- Saturday A.M. There's a medium chance for light rain along the cold front as well. - Upper level ridging returns this weekend and will last into well next week. Dry weather and above average temperatures persists as well. An upper level disturbance moving along the Hi-Line/North fergus County today will still produce a low chance (<20%) for a few isolated light showers (Precipitation amounts are expected to stay under a few hundreths). Temperatures stay near or slightly below averages today and tomorrow. Friday, the upper level ridge moving east across the region and will bring warm temperatures of mid 70s to low 80s to the region. However, the ridging will only stay briefly. Friday evening, a quick moving compact shortwave along with a Pacific cold front moves across the region. This brings gusty winds and mountian wave activity across the Rocky mountain Front and adjacent Plains. Current NBM guidance has the Rocky Mountain Front and the Montana Highway 200 corridor at a 50-80% or greater of 48kts or greater (~55mph). Therefore, the High Wind Watch remains in effect for Friday evening through Saturday morning. Wind probabilities for early Saturday morning also nears 50-80% probabilities in Fergus County so they were added to the High Wind Watch. Other areas along the Central Plains have probabilities nearing 55% for 48kts or greater. We still have to monitor the potential for wind products, but the isolated nature of these stronger gusts has held off from products for now. If guidance continue to trend higher probabilities, then the watch may be expanded. Model guidance and forecast soundings also hint at some stronger wind gusts ahead of the front Friday afternoon with deep vertical mixing. Both the Dillon and Bozeman airport give a 55% for 48kts or greater. We will need to also monitor the potential for wind products there. The warmer temperatures, stronger wind gusts, and lower RH's have caused a concern for elevated fire weather conditions Friday(see the FIRE WEATHER section for more info). There is a good chance for light precipitation along the front as well. However, there's a 30- 50% for a 0.10" or greater near or along higher elevations, and a less than 20% across lower elevations. -Wilson Sunday through next Wednesday...ensemble clusters remain in good agreement throughout the forecast period, with upper level ridging building back in over the Northern Rockies. This will allow temperatures to warm back above normal amongst dry conditions. -Moldan && .AVIATION... 02/18Z TAF Period Winds will remain elevated through the remainder of the day today before gradually weakening overnight. Expect VFR conditions through the day today and into tomorrow as high pressure builds in, which will also result in light winds on Thursday. Ludwig Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .FIRE WEATHER... Fire weather concerns will be on the increase on Friday as temperatures soar into the mid-70s to mid-80s ahead of a fast, but potent, upper level disturbance and attendant Pacific front. These above normal temperatures combined with increasing southwest to west surface winds and minimum relative humidity values in the teens will lead to elevated fire weather conditions. Given repeated events of above normal temperatures and windy conditions over the past week, the safety net that was the September rains is beginning to decrease, especially within finer fuels. Hot, Dry, and Windy (HDWI) Indices for the day on Friday are expected to rise into the 90-95th Percentile of climatology across all fire weather zones outside of zones 113 and 115. - Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 35 63 37 82 / 10 0 0 0 CTB 30 60 30 76 / 20 0 0 0 HLN 35 63 36 81 / 0 0 0 0 BZN 29 61 32 81 / 0 0 0 0 WYS 20 60 23 69 / 0 0 0 0 DLN 28 63 34 78 / 0 0 0 0 HVR 34 62 34 78 / 20 0 0 0 LWT 33 59 36 79 / 10 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Friday evening through Saturday morning for Cascade County below 5000ft-East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Fergus County below 4500ft-Judith Basin County and Judith Gap-Northern High Plains- Snowy and Judith Mountains-Southern High Plains-Southern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls