


Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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778 FXUS65 KTFX 051612 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1012 AM MDT Sat Jul 5 2025 .KEY MESSAGES... - Another round of showers and thunderstorms are expected today with isolated severe thunderstorms possible in portions of central Montana. - Temperatures will slowly warm up heading into next week with drier conditions expected to persist after today. && .UPDATE... Surface observations this morning show dew points in the upper 40s to mid 50s across much of the region in wake of precipitation yesterday. Although this surface moisture looks to decrease a bit as daytime mixing ensues (But maintain over the eastern plains), slightly cooler temperatures aloft and forcing from an approaching trough moving across the region this afternoon will result in another round of showers and thunderstorms. The risk for stronger thunderstorms today largely appears to be confined to areas on the eastern plains, where the greatest instability overlaps with favorable kinematics. Large hail has trended to be the greatest threat today in recent guidance given relatively straight and long forecast hodographs. Given surface moisture in place, mixing isn`t overly deep. Hence, strong wind gusts do not appear to be an immediate risk from thunderstorms that form. As storms move east and outside of the forecast area, the threat for strong wind gusts appears to increase as congealing of thunderstorms occurs. The forecast was updated to reflect ongoing trends. -AM && .DISCUSSION... /Issued 514 AM MDT Sat Jul 5 2025/ - Meteorological Overview: Cool and wet conditions will linger through today as the low pressure system continues its march east. Morning stratiform rain will transition into more convective showers by the afternoon. A few storms, particularly in Fergus county, may turn severe this afternoon with the main threat being strong winds. Behind the departing low, northwest flow sets up on Sunday allowing temperatures to start moderating back to normal through Monday. Weak upper level ridging builds over the state through the middle of the work week, allowing temperatures to warm back into the upper 80s to mid 90s Tuesday and Wednesday. Generally dry conditions will persist through much of the week, however, an isolated afternoon thunderstorm cannot be ruled out, particularly over higher terrain. A weak shortwave is expected to pass through Thursday through Friday which will bring temperatures back down to normal and introduce a chance for isolated afternoon thunderstorms, especially along higher terrain. In its wake quasi-zonal flow sets up which will slowly allow the region to warm back up and enter another dry period by next weekend. - Forecast Confidence & Scenarios: Thunderstorms Today: Evaluating the latest HREF, the first thing that becomes quite clear is the most significant risk for severe weather is east of our area. Which is not to say that severe weather is off the table for us. Rather the greatest threat will be any thunderstorm that kicks off in the early to mid afternoon before heading east towards the southeastern portion of the state. The main concern will be wind gusts in the 40-50 mph range with some isolated higher gusts, small hail (<0.50"), and a potential for cold air funnels. Time-wise, the greatest threat will be between 2 PM and 6 PM and the areas to watch will be Fergus, Judith Basin, and Meagher counties. In general, rainfall totals will be on the lower side Saturday afternoon with hit-or-miss higher amounts around stronger thunderstorms. After today, we enter a warmer and dry period with very little accumulation expected over the upcoming week. -thor && .AVIATION... 05/12Z TAF Period Light winds, clear skies, and recent precipitation will continue to maintain the risk for IFR/MVFR conditions due to fog/mist at the KWYS, KBZN, and KHLN terminals through 15z this morning; thereafter increasing heating will help to decrease the threat. Showers and thunderstorms, which are ongoing this morning along the Continental Divide, will increase in areal coverage beyond 15-18z Saturday across the remainder of the Northern Rockies and persist through 03-06z Sunday. While VFR conditions will predominately prevail beneath the shower and thunderstorm activity there remains the potential for temporary periods of MVFR conditions, mainly due to reduced VIS beneath heavier burst of precipitation. Main concern with thunderstorm activity during the afternoon hours today will be gusty and erratic winds, generally along and east of a KEKS, to KBZN, to KLWT line. Mountains, especially those above 9kft, will be obscured through 06-09z Sunday. - Moldan Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 75 50 81 52 / 60 20 0 0 CTB 65 46 75 47 / 70 10 0 0 HLN 74 51 82 53 / 60 20 0 0 BZN 76 45 82 49 / 70 30 0 0 WYS 71 35 75 36 / 50 20 0 0 DLN 74 43 79 46 / 50 10 0 0 HVR 77 50 82 52 / 70 40 10 10 LWT 72 47 75 49 / 80 40 0 10 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls