949 FXUS65 KTFX 221632 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1032 AM MDT Sun Jun 22 2025 Aviation Section Updated. .KEY MESSAGES... - A cool day today, along with lower elevation rain showers and mountain snow showers today. - A gradual warming trend early this week, with temperatures above normal by Wednesday. - Scattered showers and thunderstorms later this week, but nothing significant expected. && .UPDATE... /Issued 921 AM MDT Sun Jun 22 2025/ Two low pressure systems, one in Idaho, and the other in southern Saskatchewan/Northern MT will help fill in precipitation across Southwest and the North-Central MT plains this morning. By the afternoon, coverage should increase to scattered to widespread across moat of the region. Up along the Northern Rocky Mountain front, precipitation looks to decrease in the afternoon, leaving them drier than the rest of the region. An upper closed low towards the MT/ID border today will allow for a little instability to build in, which will allow for isolated thunderstorms with showers in Southwest MT. Snow levels are currently around 6,000ft, and will slowly increase throughout the morning. I will continue the Winter Storm Warning and Advisories through noon today to account for additional wet snowfall above 6,000ft. However, warming pavement temperatures will limit any additional impactful snow on mountain passes. Across Southwest MT, snow levels rising to 7,000ft and the cold closed upper-low this afternoon will allow for some convective snow showers across the higher terrain. These convective snow showers are expected to stay above pass level at this time. -Wilson && .DISCUSSION... /Issued 921 AM MDT Sun Jun 22 2025/ - Meteorological Overview: After a lull in the precipitation on Saturday, the summer storm is redeveloping for one more push through the area today. This portion of the storm should have lighter precipitation amounts than the Fri/into Sat portion. The precipitation this morning has been mostly falling along a trof over Eastern MT, with very little precip wrapping around the main upper level low now approaching Southwest MT. However, over the last hour or so, precipitation is filling in more over Central and Southwest MT, slowly though. However, that fill in of precipitation will continue this morning, with most areas of Southwest and Central MT seeing precipitation by late morning. The rain spreads into the Havre area by this afternoon. In the Cut Bank, Browning, and Shelby areas, it is looking like just a small chance for a passing shower today. Overall, in areas that do get precipitation, generally between 0.05 and 0.20 inches is expected at lower elevations with around 0.50 to 0.75 inches in the Southwest Mountains. Snow continues to fall in Glacier Park this morning as well. Overall, snow levels have generally been above 6000 feet. However, the snow levels could fall another 500 or 1000 feet this morning in some areas. Overall, mountain snow accumulations today will generally range from 2 to 6 inches, with the highest amounts in Glacier Park and the mountains of Southwest MT. The other main concern today will be the cool temperatures for June. Afternoon highs will only be in the 40s and 50s today, which is about 20 to 30 degrees cooler than normal. For tonight, the precipitation generally comes to and end, with some clearing overnight. In areas that do see some clearing, some fog could develop by Monday morning. For Monday through next Sunday, expect a nice warming trend early in the week, with warm temperatures to end the week. The airmass will become unstable enough for a passing shower/thunderstorm during the week. However, the weather systems moving through will not be that strong, and generally just light amounts of precipitation are expected with the passing storms later in the week. - Forecast Confidence & Scenarios: The main concern is the snowfall amounts this morning, along with the snow level. Overall, most of the snowfall impacts will be for elevations above 6000 feet. For elevations below 6000 feet that see snowfall, most of the snow accumulations will be on grassy areas or bridges. One other concern tonight is the potential for frost in areas that do see some clearing. Even if temperatures remain above 34 degrees, it cloud be cool enough to impact sensitive plants that are not protected. Brusda && .AVIATION... 22/18Z TAF Period MVFR/low-VFR CIGS will persist through 00-06z Monday across most terminals, with the most persistent MVFR CIGS over the plains of Central and North Central Montana. In addition to the low CIGS showers, and even an isolated thunderstorm or two, will continue to slowly pivot and lift northeast across the Northern Rockies. Best chance, which is generally 10-20% or less, for thunderstorm activity through the afternoon hours exists at the KBZN, KEKS, and KWYS terminals. Mountains will be obscured through the evening hours, with gradually clearing skies thereafter. - Moldan Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 48 38 69 43 / 90 60 40 10 CTB 52 36 63 39 / 50 20 60 20 HLN 50 38 70 45 / 80 50 30 10 BZN 52 33 71 40 / 90 40 10 10 WYS 47 23 61 26 / 100 70 10 0 DLN 47 29 63 35 / 90 70 10 0 HVR 53 38 70 44 / 90 90 40 20 LWT 47 33 66 40 / 90 80 30 10 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until noon MDT today for East Glacier Park Region. Winter Weather Advisory until noon MDT today 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- Ruby Mountains and Southern Beaverhead Mountains-Southern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls