####018005994#### FXUS65 KTFX 111416 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 816 AM MDT Sat May 11 2024 .SYNOPSIS... Warm and mostly dry conditions are expected through the weekend as upper level ridging remains over the area, with just a few light rain showers possible along the Hi Line tonight. Cooler and unsettled weather will return for early next week, with light rain expected Monday evening through Tuesday. && .UPDATE... With benign conditions forecast through much of the day, not much of an update was needed this morning. A wave passing through northwesterly flow aloft will result in a few showers and perhaps a thunderstorm or two across North-central Montana tonight into early Sunday morning. -AM && .AVIATION... 447 AM MDT Sat May 11 2024 (11/12Z TAF Period) VFR conditions will prevail beneath periods of upper level cloudiness through the TAF period, with no mountain obscuration. A weak disturbance moving over the Northern Rockies this afternoon will bring a subtle wind shift to the northwest through the early evening hours before winds go light and variable. Isolated to scattered showers are possible near the KHVR terminal beyond 06z Sunday; however, confidence in any shower impacting the terminal is low. - Moldan Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .HYDROLOGY... A Flood Warning remains in effect for Clear Creek in North Central Montana through Saturday evening, with water levels expected to slowly fall from minor flood stage to action stage tonight. Additionally, a Flood Watch remains in effect for the nearby Bears Paw Mountains through the weekend as warming temperatures and subsequent snowmelt runoff, and remaining runoff from rainwater, could push creeks and streams out of their banks. While some rainfall is expected this evening, rainfall amounts should not be high enough to significantly worsen any flooding of streams and creeks. Further south across the Island Ranges of Central Montana (i.e. Highwood, Moccasin, Judith, Little Belt, and Snowy), increased snowmelt and subsequent runoff into creeks and streams is expected through Monday as overnight temperatures and dewpoint temperatures remain above freezing. This runoff could result in waterways nearing bankful by Saturday night/Sunday morning. Hence, a Flood Watch has been issued for the Little Belts eastward toward the Lewistown area. - Moldan/AM/Ludwig && .PREV DISCUSSION... /ISSUED 447 AM MDT Sat May 11 2024/ Key Points: -Warmth continues through the weekend with periods of smoke from Canadian Wildfires -Cooler air arrives around midweek with a round of light rain Short term (through Monday)... Today will start out on the warm and dry side across North Central and Southwestern Montana as high pressure continues to exert its influence across the area, though clouds will continue to gradually work their way in from the north. Under partly to mostly sunny skies today, highs will push into the 70s and even some low 80s across the area with mostly light winds. Clouds will thicken and give way to a few rain showers overnight tonight along the Hi-Line as a weak weather system moves across Southern Alberta and Saskatchewan. While rain will be on the light side from this system, we will have to watch for any worsening of flooding of streams and creeks coming from the Bears Paw Mountains. Otherwise, the only other impact so to speak will be that the clouds will pose some difficulty for those who would try to get a second glance at the northern lights, should the ongoing solar storm persist into the overnight hours tonight. Sunday and Monday will both feature a continuation of the ongoing warmth, though we will have to watch for some smoke from wildfires that have returned to life across British Columbia over the past 48 hours as upper level flow tries to advect some of that smoke towards us. Otherwise, expect clouds to build on Monday with a few rain showers developing across Southwestern Montana as our next weather system begins to approach. Expect rain showers to become more widespread through the overnight hours as moisture continues to push into the area. Extended (Tuesday through next Saturday)... Expect periods of rainfall to continue through the day on Tuesday as moisture continues to work into the area from the north and west. For the most part, precipitation will be rainfall except at the highest elevations even as cooler air from Canada pours into the region behind a surface cold front that will work in with the rain. Beyond Tuesday, expect cool but dry weather through the end of the week as an upper level ridge sets up to our south. The quiet weather will persist into the weekend, though there will be a chance for a system to bring some slightly unsettled weather to the area for the weekend. Ludwig. && .PRELIMINARY POINT TEMPS/POPS... GTF 78 46 79 49 / 10 20 10 10 CTB 78 44 79 48 / 10 20 10 0 HLN 80 51 81 52 / 0 0 0 0 BZN 76 43 78 45 / 0 0 10 10 WYS 68 34 70 36 / 10 10 10 10 DLN 75 42 76 46 / 10 0 0 0 HVR 80 47 77 49 / 0 40 10 30 LWT 72 45 71 48 / 0 20 30 20 && .TFX WATCHES/WARNINGS/ADVISORIES... Flood Watch through Sunday morning for Bears Paw Mountains and Southern Blaine. Flood Watch from noon MDT today through Monday morning for Cascade County below 5000ft-Fergus County below 4500ft-Judith Basin County and Judith Gap-Little Belt and Highwood Mountains- Meagher County Valleys-Snowy and Judith Mountains-Western and Central Chouteau County. && $$ http://www.weather.gov/greatfalls