Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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296 FXUS65 KTFX 141639 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1039 AM MDT Fri Jun 14 2024 .SYNOPSIS... Showers and thunderstorm chances return this afternoon with the small chance for a few severe wind gusts and small hail in Southwest Montana. Windy conditions expected along the Rocky Mountain Front this weekend, along with light precipitation across the region. Better chances for widespread precipitation and mountain snow return Monday and Tuesday. Below average temperatures expected beginning of next week, but will warm up mid week. && .UPDATE... Aside from a few isolated rain showers this morning (and rumbles of thunder in the Gallatin Valley), expect mostly sunny skies across the area with a few isolated thunderstorms across Southwestern Montana this afternoon. Looking ahead, next week`s system is showing some uncertainty, which will result in some changes to the forecast for this system with the afternoon forecast package, especially across the plains. Ludwig && .AVIATION... 14/12Z TAF Period VFR conditions prevail over the next 24 hours; however, forecast confidence in the evolution of afternoon showers and thunderstorms is low given the presence of nocturnal showers and even an isolated thunderstorm already this morning across portion of Central and Southwest Montana. Short-term model guidance has struggled all night with this nocturnal convection, which is leading to lower than normal forecast confidence for this TAF package. Chances for showers and thunderstorms are expected to increase through the afternoon today along and east of a KEKS to KLWT line. CIGS/VIS beneath or near these showers are not expected to fall below VFR, but low-VFR conditions may briefly occur. Otherwise, light winds are generally expected across most terminals outside of KCTB where breezy and gusty west winds will develop by Friday afternoon. Some mountain obscuration is possible over the next 24 hours. - Moldan Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 500 AM MDT Fri Jun 14 2024/ Today...Some early morning showers will continue to move across primarily Southwest Montana. A dynamic upper level trough moving east into the weekend will bring an active pattern through mid next week. A small upper level shortwave moving through will spark scattered showers/storms long a front across MT shortly after noon. The Storm Prediction Center has put southeastern Beaverhead/Madison Counties and Southern Gallatin County in a marginal risk for a 5% chance of severe storms containing gusty winds and small hail. Most of the lower elevations will experience one last day of 80s temperature before colder air moves in over the weekend. Saturday and Sunday...Colder air moves in for the weekend behind the front. Another upper level disturbance moving through the region will bring more light showers/thunderstorms to the region Saturday morning and afternoon. Additionally, stronger winds aloft will bring windy conditions to the Rocky Mountain Front between Saturday afternoon and Sunday. There`s a 50-60% chance of the Continental Divide of exceeding 64mph wind gusts. There`s a 70% chance the Cut Bank area can exceed 55mph wind gusts. Monday through Tuesday...An upper level low will move east across the region, bringing in a more dynamic weather system to the CWA. There`s a 40-70% chance of lower elevations exceeding 0.50" of QPF Monday and Tuesday. Higher QPF amounts are possible at the higher elevations. Higher elevations have a 50% chance of exceeding 1" of QPF and a 20% of exceeding 2". Snow levels will fall below 7,000ft and can fall to slightly below 6,000ft at times depending on how much cold air funnels down. As a result, heavy wet snow will impact the higher elevations, which has prompted the Winter Storm Watches. There`s a 40-60% chance of locations in the watch exceeding 6" of snow. Given snow probabilities are similar to the Southwest MT mountains, and higher QPF amounts are concentrated along the Belts and Little Belts region, I have opted to include them in the Winter Storm Watch for the same time frame. Heavy wet snow can weigh down tree limbs and power lines, and can cause hazardous conditions in the backcountry. With the colder air moving in, temperatures for Monday and Tuesday will see below average temperatures. Overnight lows will drop below freezing at higher elevations. Wednesday and beyond...The upper level trough will move out of the area brining warmer and drier conditions. Although, a few disturbances will try to bring low end precipitation chances during this time frame. -Wilson && .PRELIMINARY POINT TEMPS/POPS... GTF 85 52 72 43 / 20 20 50 0 CTB 78 46 64 41 / 0 0 30 0 HLN 87 54 74 42 / 20 20 40 0 BZN 85 50 77 37 / 30 40 40 10 WYS 77 44 69 35 / 40 20 10 0 DLN 84 50 73 34 / 20 20 10 0 HVR 85 52 75 45 / 20 10 50 20 LWT 80 49 75 38 / 20 50 70 20 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Saturday afternoon through late Saturday night for Eastern Glacier, Western Toole, and Central Pondera- Northern High Plains. Winter Storm Watch from Monday morning through Tuesday evening for East Glacier Park Region-Southern Rocky Mountain Front. Winter Storm Watch from Monday evening through Tuesday evening for Big Belt, Bridger and Castle Mountains-Elkhorn and Boulder Mountains-Gallatin and Madison County Mountains and Centennial Mountains-Little Belt and Highwood Mountains-Northwest Beaverhead County. && $$ http://www.weather.gov/greatfalls