FXUS65 KTFX 221606 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1006 AM MDT Wed May 22 2024 .SYNOPSIS... Isolated afternoon and evening thunderstorms develop and move through the region, again, today. The main impact from these storms is strong and erratic gusty winds. As the day progresses, widespread precipitation impacts the region. Significant snow amounts are forecast for mountain elevations, with wintry impacts to some lower elevations, as well. This system continues to impact the region into the early hours of Friday morning. && .UPDATE... The morning update has been published. Light rain showers are spreading from west to east this morning. This activity will increase this afternoon and weak instability will introduce chances for thunderstorms as well. Severe weather is not expected, but brief downpours, small hail, and gusty winds can be expected with the stronger cells in addition to a few lightning strikes. Winter weather is still expected tonight into Thursday, including heavy, wet, mountain snow, especially over the central and southwest mountain passes. All winter highlights are in good shape and the forecast was freshened with the latest data. - RCG && .AVIATION... 22/12Z TAF Period Note: The NWS Great Falls Weather Forecast Office manages the following TAFs: KCTB, KHVR, KGTF, KLWT, KHLN, KBZN, KEKS and KWYS. All TAFs begin under degrading VFR conditions. The next system arrives through the day, today. Conditions, ultimately, become MVFR/IFR/LIFR at all airfields. The initial concern is for lower elevation rain showers and scattered thunderstorms with higher elevation snow showers through daylight hours. Snow levels fall down as low as valley floors at times, tonight. Expect mountain obscuration. - Fogleman Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .HYDROLOGY... A Flood Watch remains in effect for areas near creeks and streams over in the Little Belt Little mountains tonight through Friday morning. Current probabilistic forecasts support one to two inches of rainfall/liquid equivalent precipitation through Friday. Snow levels will fluctuate with this weather system, with mostly snow expected for areas above 6,000 feet. However, there are concerns for flooding on area creeks and streams given recent precipitation/saturated soils and at least a portion of the upcoming precipitation falling as rain at all elevations. Those near water should be vigilante and ready to seek higher ground if flooding occurs. && .PREV DISCUSSION... /ISSUED 430 AM MDT Wed May 22 2024/ Note: The forecast area for the National Weather Service Great Falls Weather Forecast includes north central, central and southwest Montana. Today and Tomorrow...An upper level closed area of lower heights rolls southeastward across The Treasure State. The resultant impacts include precipitation that enters our region from the west, and becomes widespread throughout the day, today. Temperatures cool, and significant amounts of snowfall are forecast across many of the mountainous regions of central and southwest Montana. For this reason, most of these mountain regions are under Winter Storm Warnings, with The Snowy mountains added under a Winter Storm Warning during the issuance of this forecast. The probability of snow amounts exceeding 6 inches, is at 80% or more across our mountain zones. Heavy wet snow may cause damage to trees and power lines. With the approach of the Memorial Day Weekend, we are particularly concerned for those who may wish to venture into the backcountry. The conditions that we are forecasting are associated with high incidents of hypothermia. Having said this, our concern is not limited to those in the backcountry. Travel will be dangerous across some mountain passes. Additionally, some of our lower elevations are forecast to experience impacts from snow. Surfaces will be slushy and slippery. This system exits the region by early Friday morning; however, considering the amount of moisture forecast, flooding impacts are a concern. Please, see the HYDROLOGY section below for more details. Friday through Sunday...Active weather continues with only short reprieves in moisture. With temperatures warming, most moisture from the ongoing active weather pattern, falls as rain. having said this, some mountain snow is forecast, and concerns for those wishing to recreate in the outdoors over the Memorial Day Weekend, continues. Monday and Tuesday..The forecast is for warm, dry and mild conditions, with Tuesday's low elevation high temperatures ranging in the mid 70s to low 80s. Wednesday...The mid week period of next week shows a slight chance of precipitation; however, confidence is low, as this system is several days out. - Fogleman && .PRELIMINARY POINT TEMPS/POPS... GTF 58 37 48 36 / 90 90 80 20 CTB 54 34 51 35 / 100 80 40 30 HLN 59 37 48 36 / 100 100 90 10 BZN 59 32 45 28 / 90 100 100 20 WYS 47 25 41 24 / 80 90 80 20 DLN 57 30 44 26 / 100 90 90 10 HVR 58 37 53 36 / 70 70 40 20 LWT 57 34 43 31 / 80 90 90 20 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 6 PM this evening to noon MDT Thursday for Elkhorn and Boulder Mountains-Northwest Beaverhead County- Ruby Mountains and Southern Beaverhead Mountains-Southern Rocky Mountain Front-Upper Blackfoot and MacDonald Pass. Winter Weather Advisory from midnight tonight to 6 PM MDT Thursday for Gates of the Mountains. Flood Watch from 6 PM MDT this evening through Friday morning for Little Belt and Highwood Mountains. Winter Storm Warning from 6 PM this evening to 6 PM MDT Thursday for Big Belt, Bridger and Castle Mountains-Gallatin and Madison County Mountains and Centennial Mountains-Little Belt and Highwood Mountains. Winter Weather Advisory from 6 PM this evening to 6 PM MDT Thursday for Beaverhead and Western Madison below 6000ft- Gallatin Valley-Madison River Valley-Missouri Headwaters. Winter Storm Warning from 6 AM to 6 PM MDT Thursday for Snowy and Judith Mountains. && $$ http://www.weather.gov/greatfalls