


Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
715 FXUS65 KTFX 021311 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 711 AM MDT Sat Aug 2 2025 .KEY MESSAGES... - Scattered showers and thunderstorms redevelop by this afternoon and evening, most numerous along the Rocky Mountain Front and the Hi- Line. - The primary thunderstorm hazards for today will be brief heavy downpours, gusty winds, and hail in addition to lightning. - Additional daily rounds of Scattered showers and thunderstorms continue heading into next week, with the strongest and most widespread activity expected Monday into Tuesday. - Temperatures generally remain near average through at least Wednesday. && .UPDATE... The on-going forecast is capturing current shower activity over the plains of North Central Montana well and no morning update is needed or planned. - Moldan && .DISCUSSION... /Issued 527 AM MDT Sat Aug 2 2025/ - Meteorological Overview: Showers and some embedded thunderstorms continue to diminish over Blaine County this morning while only a few isolated showers or sprinkles are being observed over the remaining portions of the forecast area. The combination of a weak low along the Canadian border and ridging becoming more pronounced over the Great Basin will shift the general flow aloft to a more of a westerly direction over the next couple of days. Precipitable water values will remain excessively high today over North-central Montana, generally ranging between an inch and an inch and a half, but there will be a slight decrease in instability with CAPE dropping to around 1,000 J/kg and less. Additionally, the westerly flow aloft will be less favorable for storm clustering and back building for most locations except along the Canadian border. All of these factors should reduce the overall flash flooding threat despite a continued slow steering current. Storm coverage decreases further on Sunday as the exiting Canadian low shunts much of the anomalous moisture eastward. Still there will be some activity in the Milk River Valley and an initial wave of showers and thunderstorms will creep back into the southwest by the evening hours in response to a trough moving into the Pacific Northwest. An unstable southwesterly flow aloft returns to the Northern Rockies by Monday, supplying bulk shear over 40 kts and boosting precipitable water back over the inch mark. There will be waves of showers and thunderstorms passing through Southwest and North- central Montana Monday afternoon through Tuesday. The stronger storms will be capable of strong, gusty winds, hail, and brief heavy downpours. The overall weather pattern looks to be much more progressive next week compared to recent days. Another fast moving Pacific trough looks to move through the Northern Rockies during the second half of the week. Although there are timing and depth issues to work out, there looks to be more showers and thunderstorms with temperatures dipping slightly below average at least temporarily. - RCG - Forecast Confidence & Scenarios: Daily rounds of showers and thunderstorms continue into next week... Another round of scattered showers and thunderstorms redevelop again today, but less instability and a westerly flow aloft is expected to reduce the overall flood threat for most locations. The one potential exception to this will be along the Canadian border, particularly in northern Hill and Blaine counties. With most hires guidance supporting the heaviest activity remaining over Alberta/Saskatchewan, no flash flood products are being considered at this time. Regardless, the stronger storms will be capable of producing localized heavy downpours, so conditions will continue to be monitored here given amount of rainfall received in recent days. There is an expectation of less storm activity for most of Sunday before an initial wave of storms begins to creep back into Southwest Montana Sunday evening. Higher moisture levels, wind shear, and instability will bring a return of northward moving strong to severe thunderstorms Monday into Tuesday. The primary hazards will be strong, gusty winds, hail, and brief heavy downpours. - RCG && .AVIATION... 02/12Z TAF Period Lighter end showers are already developing over North- central Montana this morning. Additional scattered shower and thunderstorm activity is expected to develop this afternoon and evening, most numerous along the Rocky Mountain Front and the Canadian border. Some of the stronger storms will be capable of producing gusty winds, brief downpours, and small hail in addition to lightning. VFR conditions are generally expected, but low VFR cloud cover and brief category degradation of visibility can be expected, mostly for the northern terminals. Most showers and storms should diminish and end after 03/04Z. - RCG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 80 57 83 55 / 50 20 0 0 CTB 73 56 76 51 / 70 20 10 0 HLN 80 56 86 55 / 30 20 0 10 BZN 83 51 85 50 / 20 20 10 10 WYS 79 39 76 39 / 30 40 10 10 DLN 79 47 80 47 / 40 20 10 10 HVR 82 59 81 56 / 60 50 30 10 LWT 77 53 78 53 / 50 30 10 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls