FXUS65 KTFX 060533 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1133 PM MDT Tue May 5 2026 Aviation Section Updated. .KEY MESSAGES... - Cold night tonight, with most, if not all locations dipping well into the 20s or colder. - Temperatures trend closer to average after today. - Intermittent stretches of showers and a few thunderstorms through the week. && .UPDATE... No evening updated planned for. Current forecast is on track. Showers are decreasing, with skies clearing out. Going to be chilly in the morning. A sunny/dry day expected on Wed, but showers return Wed night. Brusda && .DISCUSSION... /Issued 300 PM MDT Tue May 5 2026/ - Meteorological Overview: Cyclonic northerly to northwesterly flow aloft continues through the remainder of the afternoon and early evening, fostering showers and snow showers through sunset. Flow aloft trends more anticyclonic tonight, which will aid in clearing skies by daybreak Wednesday. Given the clearing skies and an already cool airmass in place, overnight lows tonight look to fall well into the 20s, and well into the teens or colder in cold prone locations. Some patchy fog cannot be ruled out tonight, particularly in areas that see more than a few hundreths of an inch of precipitation through the remainder of the day today. Temperatures trend a bit warmer for Wednesday, but the cold start will limit the overall magnitude of warming in a few areas. A weak wave progressing through the northwesterly flow Wednesday night will result in showers and perhaps a thunderstorm or two, which linger through much of Thursday. Another brief stretch of more benign weather early Friday quickly diminishes as another wave aloft moves through late Friday into Saturday. Uncertainty is higher with this system, largely related to magnitude and location of the upper wave. The main takeaway for Saturday will be for cooler temperatures with opportunities for precipitation through much of the day. Ensemble averages/cluster guidance favors ridging Sunday into the first half of next week, which would largely promote a warmer/drier stretch. -AM - Forecast Confidence & Scenarios: Cold temperatures tonight: Only a few areas across the region have more than a 10% probability for a low temperature tonight that is warmer than 30 F. Additionally, a few areas will challenge record lows for the calendar day Wednesday. Protective measures may need to be taken for sensitive vegetation through the morning Wednesday. -AM Precipitation Saturday: Uncertainty related to the position and strength of the upper level system late Friday into Saturday is resulting in a large range of scenarios for any given location. 10th to 90th percentile precipitation amounts over the Golden Triangle are a trace to a half inch respectively, indicating lower confidence in specifics at this range. -AM && .AVIATION... 06/06Z TAF Period Expect decreasing clouds over the CWA through 12z, otherwise quiet weather conditions are expected through 02z Thu. Surface winds will be breezy at times this afternoon. Clouds will increase after 00z Thu, with a chance for showers along the Rocky Mountain Front from Butte northward to the Canadian border mostly after 03z Thu, and in the Bozeman area after 06z Thu. Mountains passes will start to become obscured by clouds/precip after 02z Thu. Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 25 72 49 67 / 0 0 40 50 CTB 22 72 46 67 / 0 0 20 30 HLN 27 71 47 69 / 10 0 20 30 BZN 22 67 39 69 / 0 0 20 20 WYS 17 60 33 64 / 10 0 10 30 DLN 23 68 42 71 / 0 0 10 0 HVR 23 68 38 72 / 0 0 10 20 LWT 21 62 41 63 / 0 0 30 60 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls