FXUS65 KTFX 060521 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1121 PM MDT Sat Apr 5 2025 Aviation Section Updated. .KEY MESSAGES... - Dry and trending warmer through Monday. - Breezy to windy at times late Monday through Wednesday. - Scattered precipitation Monday night through Wednesday as a series of weak weather systems move across the area. && .UPDATE... /Issued 659 PM MDT Sat Apr 5 2025/ Slight adjustments to the winds based on the latest model guidance but otherwise no major changes were made to the going forecast. -thor && .DISCUSSION... /Issued 659 PM MDT Sat Apr 5 2025/ - Meteorological Overview: A high amplitude upper-level ridge with axis from the US west coast through NW Canada will shift east through the remainder of the weekend and across MT Monday. Sunny/clear and dry conditions persist through Sunday night with some increase in clouds expected Monday as the ridge axis moves east and flow aloft turns to the W/SW. Daytime temperatures continue to climb through Monday when some lower elevation locations may warm to around 70. Somewhat breezy southwest winds on the plains this afternoon, mainly due to daytime heating/mixing and weak troughing to the lee of the Rockies, will diminish this evening but redevelop Sunday afternoon. An upper level low currently well offshore will open to a broader trough early next week, nudging the ridge off to the east Monday night with a series of generally weak disturbances moving across the region in a zonal/westerly flow aloft Monday night through Wednesday. This brings windier conditions, initially with the passage of a Pacific cold front Monday night but also with additional waves embedded in the moderate westerly flow aloft that follows Tuesday and Wednesday. There will be some opportunities for precipitation Monday night through Wednesday with better chances near the continental divide and scattered precipitation further east. Temperatures cool back to near seasonal averages for the mid-week period before warming again late next week with broad ensemble support for upper level ridging re-developing. - Forecast Confidence & Scenarios: Clear skies and dry conditions will allow for efficient cooling tonight despite overall warming aloft with the building upper ridge, so minimum temperatures were adjusted toward cooler guidance, especially across portions of central MT where snow-cover lingers. Precipitation amounts are minimal across much of the area with the series of disturbances next week with probabilities for amounts in excess of 0.25" as high as 20-30% across the mountains but generally less than 10% elsewhere. Looking ahead to next weekend, most (85%) of longer range model ensembles eventually bring troughing into the NW US and Northern Rockies with considerable timing differences still at this range. There is a small subset (10%) of most longer range model ensemble systems that support a larger/spring-type storm scenario late next weekend or early next week. Hoenisch && .AVIATION... 06/00Z TAF Period VFR conditions will prevail across the CWA through the period, with just some passing high clouds. Brusda Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 30 62 36 67 / 0 0 0 0 CTB 31 61 32 64 / 0 0 0 0 HLN 31 61 35 66 / 0 0 0 10 BZN 25 58 30 62 / 0 0 0 0 WYS 14 52 20 53 / 0 0 0 0 DLN 27 58 31 61 / 0 0 0 0 HVR 29 65 31 72 / 0 0 0 0 LWT 30 57 34 66 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls