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
082 FXUS65 KTFX 250948 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 348 AM MDT Sat May 25 2024 .SYNOPSIS... It will be mostly cloudy today, with rain showers or a thunderstorm developing over Southwest MT this morning, and then moving northeast into Central MT this afternoon. Snow is possible in the mountains, mostly above 7000 feet. The showers exit the area on Sunday, with drier and warmer temperatures expected for Monday and Tuesday. There will be another chance for storms Tuesday afternoon and evening, some of which could be strong. && .DISCUSSION... Today through Monday...Patchy morning fog will affect the Hi-line area through about 10 AM this morning. Otherwise, an upper level disturbance will move from southwest to northeast through the CWA today. Expect rain/isolated thunderstorms to develop this morning over Southwest MT and gradually spread northeastward through the day today. Overall, rainfall amounts should be light, about 0.10 inches at lower elevations and around 0.20 inches in the mountains. I will issue a SPS this morning, as precipitation should be snow by tonight, mostly for elevations above 7000 feet in the Big Sky area. The system will be slow to exit the area, with some light showers lingering into Sunday. Monday is looking mostly dry, as an upper level ridge starts to build over the CWA. Slightly below afternoon temperatures are expected today and Sunday, while temperatures will be warming up a bit above normal by Monday. It will be windy at times on Sunday for areas along/west of the I-15 corridor over North Central MT. Tuesday through Saturday...An upper level ridge will be over the area on Tuesday morning, which will quickly break down by Tuesday afternoon, as an upper level trof approaches from the west. Tuesday will likely be the warmest day over the next week, but I did lower NBM guidance a few degrees for Tuesday afternoon, as it might be too warm. Otherwise, the main concern Tuesday is for the potential for severe storms Tuesday afternoon/evening. With the flow aloft becoming southwest, it will be unstable by late afternoon. However, it is not that unstable, thus the potential for widespread severe storms looks low at this time. On Wednesday, the main cold front moves though. Temperatures will start to cool a bit, as well as the potential for heavy rainfall over Central MT. Right now there is about a 30 percent chance for locations between Great Falls and Lewistown to receive 0.50 inches of rainfall. This would be convective rainfall, thus portions of Central MT are in a marginal risk for excessive rainfall during this period. It does remain unsettled for Thus/Fri with scattered showers continuing and afternoon temperatures just a few degrees below normal. Brusda && .AVIATION... 25/06Z TAF Period VFR conditions will prevail during this TAF period at all terminals. The main concern for this TAF period is rain showers and thunderstorms Saturday afternoon and evening. At the KEKS, KBZN, KWYS, KHLN, and KLWT terminals there is a 50% chance for thunderstorms Saturday afternoon and evening and so a PROB30 group was included for them in those TAFs. At the KGTF and KHVR terminals late Saturday afternoon and evening there is a 50% chance for thunderstorms and so a PROB30 group was included for those TAFs. At the KCTB terminal there is a 50% chance for rain showers Saturday afternoon and so a PROB30 group was included for it. At the KWYS, KEKS, KBZN, and KLWT terminals there will be rain showers Saturday afternoon through the end of the TAF period. At the KHVR and KGTF terminals there is a 50% chance for rain showers Saturday afternoon and early evening. Another concern for this TAF period are wind gusts from 15 to 24 kts at the KHLN and KCTB terminals Saturday afternoon and evening. Due to the rain showers, mountain obscuration will occur intermittently primarily across Southwestern Montana Saturday afternoon and evening. -IG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 64 41 62 39 / 50 30 10 0 CTB 63 40 60 39 / 30 10 10 0 HLN 65 42 64 43 / 60 20 10 0 BZN 63 36 62 36 / 70 80 10 0 WYS 54 33 54 30 / 70 70 20 0 DLN 60 35 62 36 / 70 40 0 0 HVR 69 43 65 43 / 40 40 30 10 LWT 62 37 58 37 / 70 60 20 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls