FXUS65 KTFX 091725 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1125 AM MDT Fri May 9 2025 Aviation Section Updated. .KEY MESSAGES... - Warmer, with dry conditions today. - Continued warming, with isolated severe storms Saturday afternoon. - Thunderstorms continue into Sunday, with a spring storm possible early next week, along with cooler temperatures. && .UPDATE... /Issued 819 AM MDT Fri May 9 2025/ Satellite imagery shows just some high clouds moving across the Northern Rockies and MT this morning over a building upper level ridge centered over the SW US. At the surface, high pressure is sliding southeast across the Canadian Prairies, supporting generally light surface winds across the area this morning with south to southeast winds veering to southwesterly this afternoon as the high moves off to the east. Overall quiet weather conditions are expected for the entire area today with temperatures warming around 5 degrees up from yesterday. Hoenisch && .DISCUSSION... /Issued 819 AM MDT Fri May 9 2025/ - Meteorological Overview: With an upper level ridge of high pressure building over the CWA today, expect quiet conditions, along with the continued warming trend. On Saturday, expect afternoon temperatures to continue to warm, with some record high afternoon temperatures possible. Additionally, an upper level disturbance will move from southwest to northeast through the CWA during the late afternoon and evening hours. With inverted V soundings, combined with some instability, a few severe storms are possible. The latest SPC HREF progs some storms producing wind gusts over 60 mph. Additionally, some storms will produce little rainfall. On Sunday, the upper level ridge begins to break down, thus it will not be as warm. Expect several upper level disturbances to move through the CWA throughout the day. Some storms could be on the strong side once again. For early next week, both the EC/GFS continue to prog a spring storm to move through the CWA. Right now, it seems the southern and central portions of the CWA would be the most favored area, but any shift to the north would increase the chance for heavier precipitation northward. Additionally, the airmass will continue to cool, especially at higher elevations. Thus snow is looking likely for mountain areas above 7000 feet. There is the chance snow levels could be lower at times during overnight periods or during periods of heavier precipitation. Expect scattered showers to continue for the later half of next week, along with a very slow warming trend. - Forecast Confidence & Scenarios: The main concern is the thunderstorm potential on Saturday. There currently is a marginal risk for severe storms over a good portion of the CWA on Saturday. The main impact from any severe storms will be gusty winds, but some hail can't be ruled out. Overall, pops are generally on the low side at this time for Saturday, as precipitation amounts are expected to remain low. On Sunday, it will not be as warm, but there will still be enough instability for a few strong storms. Again the main threat from any stronger storms on Sunday will be gusty winds and hail. For the spring storm potential early next week, overall this storm looks fairly similar to the recent spring storm earlier this week. Snow will fall at higher elevations in the mountains, with a good rainfall at lower elevations. Rainfall amounts around one inch look reasonable across much of Central and Southwest MT with this system, at this time. Brusda && .AVIATION... 09/18Z TAF Period VFR conditions will prevail at all terminals during the duration of this TAF period with mostly scattered mid/high level clouds. Between 10/18Z and 11/00Z there is a 10% chance for a thunderstorm at the KBZN terminal. Any thunderstorm will bring lightning, and gusty, erratic winds. -IG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 80 50 87 51 / 0 0 20 30 CTB 77 46 82 48 / 0 0 10 20 HLN 82 50 86 53 / 0 0 30 20 BZN 78 46 83 50 / 0 0 10 20 WYS 71 34 74 42 / 0 0 0 20 DLN 76 46 81 50 / 0 0 10 10 HVR 81 49 90 50 / 0 0 10 40 LWT 75 52 83 53 / 0 0 10 40 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls