Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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075 FXUS65 KTFX 120826 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 226 AM MDT Wed Jun 12 2024 .SYNOPSIS... Windy conditions continue with near normal high temperatures today. Quieter conditions for tomorrow with a return of scattered thunderstorms across Southwest and Central Montana Friday. A cooler and wetter weather pattern change for this weekend into next week. && .DISCUSSION... Today through tomorrow night... Windy conditions across North Central and Southwest Montana continue through this afternoon then decrease through the overnight period tonight. Wind gusts are still supported by the latest National Blend of Models (NBM) 4.2 probabilistic data of reaching 30 to 40 mph from the Rocky Mountain Front to across the Hi-Line all the way down to Great Falls from now through this afternoon. Dry conditions and mostly sunny skies are in store today and tomorrow afternoon with near normal high temperatures forecasted in the 70s and low 80s in a few valley locations. Friday through Sunday... Upper level troughing quickly moves through Friday and Saturday bringing scattered rain showers and thunderstorms across Southwest and North Central. A surface cold front moves through Friday night bringing cooler temperatures for Saturday and windy conditions Saturday afternoon. For Friday`s thunderstorms, a line of storms can develop from Big Sky/Bozeman to Lewistown between noon and 5 PM and move northeast through the early evening hours Friday night. A few thunderstorms could become on the strong side with primary concerns being lightning, gusty winds, and small size hail. Then for Saturday, thunderstorms could develop from Lewistown to White Sulphur Springs line and move eastward during the late afternoon into early evening hours. Otherwise a few scattered light rain showers could develop across Central Montana Saturday evening. National Blend of Models 4.2 probabilistic data suggests wind gusts have high probabilities (greater than 75 percent) of reaching greater than 30 mph for along the Rocky Mountain Front to Helena and down into Southwest Montana for Saturday afternoon into the overnight hours decreasing during the early morning hours Sunday. A break in the precipitation (dry conditions favored) is in store for Sunday before our next weather system moves in for Monday. Monday through middle of next week... Our next weather system moves into the region Monday bringing beneficial precipitation to Southwest and North Central Montana. Ensemble model guidance is favoring upper level troughing to move through next week bringing these unsettled weather conditions to our region. While precipitation amounts are still uncertain with model guidance, what is known at this forecast time is higher elevations of our mountainous terrain could see snowfall as the primary precipitation type and elsewhere could see rainfall. Those adventuring outdoors in mountainous terrain next week should begin planning on winter weather and raw backcountry conditions. The Climate Prediction Center (CPC) 6 to 10 day outlook has our region in 50 to 60% probability of temperatures likely below normal for next week. Ensemble and deterministic model guidances are hinting at 15 to 25 degrees below normal during this timeframe with forecasting highs in the 50s and 60s where normal temps are in the 70s and low 80s. Webb && .AVIATION... 12/00Z TAF Period VFR conditions prevail this TAF period. The concern will be for gusty winds across the plains through the TAF period. Confidence for long duration LLWS was not high enough to include in plains TAFs at this time. Airfields that are a bit more sheltered across the plains should expect instances of LLWS through the overnight. Otherwise the only other concern will be for an isolated shower or two across SW MT and along the Rocky Mountain Front this evening. Confidence in any shower impacting a terminal is too low to mention in TAFs. -AM Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 76 41 78 49 / 0 0 0 0 CTB 71 39 76 46 / 0 0 0 0 HLN 81 47 85 54 / 0 0 0 0 BZN 81 43 83 50 / 0 0 0 0 WYS 76 38 80 45 / 0 0 0 10 DLN 80 43 85 50 / 0 0 0 0 HVR 77 45 77 52 / 0 0 0 0 LWT 74 42 75 50 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls