Spot Forecast
Issued by NWS Great Falls, MT

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073
FNUS75 KTFX 281023
FWSTFX

Spot Forecast for South Fork Humbug...HIDC
National Weather Service Great Falls MT
423 AM MDT Fri Aug 28 2026

Forecast is based on forecast start time of 0600 MDT on August 28.
If conditions become unrepresentative...contact the National Weather
Service.

.DISCUSSION...

Temperatures will cool into the weekend as a large upper level
disturbance over the Pacific Northwest pivots east and over the
Northern Rockies. Daily chances for showers and thunderstorms will
exist through Sunday, with the best opportunity for wetting
rainfall arriving between 1200 Saturday and 1200 Sunday; with an
85% chance of receiving 0.10" of rainfall during this timeframe
and a 70% chance of 0.25". Winds will increase into the day on
Sunday, with a 90% chance that gusts exceed 25 mph during the
afternoon and evening hours and a 25% chance that gusts exceed 40
mph.

.TODAY...

Sky/weather.........Mostly cloudy (70-80 percent) then becoming
                    partly sunny (50-60 percent). Patchy smoke in
                    the morning and early afternoon. Slight chance
                    of rain showers late in the afternoon.
CWR.................5 percent.
Chance of thunder...9 percent.
Max temperature.....75-80.
Min humidity........22-27 percent.
Wind (20 ft)........
 Slope/valley.......Southwest winds around 5 mph becoming west 5 to
                    10 mph late in the morning.
 Ridgetop...........Southwest 10 to 15 mph.
Mixing height.......7500 ft AGL.
Transport winds.....Southwest 5 to 10 mph shifting to the west
                    around 15 mph late in the afternoon.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........69  85  82  86  81  82  75  67  84  69  50  60
Weather cov.....PTY PTY PTY PTY PTY PTY PTY PTY PTY SCH SCH SCH
Weather type....SMK SMK SMK SMK SMK SMK SMK SMK SMK RW  RW  RW
Tstm cov........
CWR.............0   0   0   0   0   0   10  10  10  10  10  10
Chc of thdr (%).0   0   0   0   0   0   0   0   0   10  10  10
Temp............51  50  51  55  61  66  70  73  75  75  77  76
RH..............63  64  64  63  56  48  39  34  29  27  27  28
20 FT wind dir..SW  SW  SW  SW  SW  W   W   W   W   W   W   W
20 FT wind spd..5   0   0   0   0   5   5   5   5   10  10  10
20 FT wind gust.    5   5   5   5   10  10  15  15  15  15  15
Ridge wind dir..SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  W   W
Ridge wind spd..15  15  15  15  15  15  15  15  15  15  15  15
Mix hgt (kft)...0.5 0.5 0.5 0.5 1.0 2.0 3.5 5.0 6.5 7.5 7.5 7.0
Transp wind dir.SW  SW  SW  SW  SW  SW  SW  SW  SW  SW  W   W
Transp wind spd.5   5   5   5   5   5   10  10  15  15  15  15

.TONIGHT...

Sky/weather.........Mostly cloudy (55-65 percent). Slight chance of
                    rain showers early in the evening. Patchy smoke.
CWR.................5 percent.
Chance of thunder...10 percent.
Min temperature.....48-53.
Max humidity........61-66 percent.
Wind (20 ft)........
 Slope/valley.......West winds 5 to 10 mph early in the evening
                    shifting to the south overnight and becoming light.
 Ridgetop...........West 10 to 15 mph decreasing to around 5 mph.
Mixing height.......500 ft AGL.
Transport winds.....West 10 to 15 mph shifting to the southwest
                    around 5 mph early in the evening, then
                    shifting to the southeast after 3 am.

TIME (MDT)      6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........61  48  51  62  64  58  50  69  68  71  71  80
Weather cov.....SCH SCH SCH PTY PTY PTY PTY PTY PTY PTY PTY PTY
Weather type....RW  RW  RW  SMK SMK SMK SMK SMK SMK SMK SMK SMK
Tstm cov........
CWR.............10  10  10  10  10  10  10  10  10  10  10  10
Chc of thdr (%).10  10  10  10  10  10  10  10  10  0   0   0
Temp............75  73  68  64  62  60  59  57  56  55  52  52
RH..............28  35  41  48  50  53  55  56  58  60  57  58
20 FT wind dir..W   W   SW  SW  SW  S   S   S   S   SE  S   S
20 FT wind spd..10  5   5   5   5   5   5   0   0   0   0   0
20 FT wind gust.15  10  10  10              5   5   5   5   5
Ridge wind dir..W   SW  S   S   S   SW  SW  SW  W   W   W   SW
Ridge wind spd..15  10  5   5   5   5   10  10  5   5   5   5
Mix hgt (kft)...5.5 3.5 1.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Transp wind dir.W   W   SW  W   W   SW  SW  SW  W   S   SE  SE
Transp wind spd.15  10  5   5   5   5   5   5   5   5   5   5

.SATURDAY...

Sky/weather.........Cloudy (85-95 percent) then becoming partly
                    sunny (60-70 percent). Patchy smoke early in
                    the morning. Chance of rain showers in the
                    morning, then rain showers likely and chance of
                    thunderstorms in the afternoon.
CWR.................5 percent increasing to 20 percent in the
                    afternoon.
Chance of thunder...30 percent.
Max temperature.....69-74.
Min humidity........37-42 percent.
Wind (20 ft)........
 Slope/valley.......Light winds becoming southwest around 5 mph
                    early in the morning, then shifting to the west
                    in the late morning and afternoon. Gusty and
                    erratic winds expected near thunderstorms.
 Ridgetop...........Southwest 5 to 10 mph increasing to 10 to 15
                    mph early in the morning.
Mixing height.......8500 ft AGL.
Transport winds.....Southwest 5 to 10 mph increasing to around 15
                    mph in the afternoon.

TIME (MDT)      6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........92  92  92  57  57  57  66  66  66  77  77  77
Weather cov.....SCH CHC CHC SCH SCH SCH CHC CHC CHC LKY LKY CHC
Weather type....RW  RW  RW  RW  RW  RW  RW  RW  RW  RW  RW  RW
Tstm cov........                        SCH SCH SCH CHC CHC CHC
CWR.............10  10  10  10  10  10  20  20  20  20  20  20
Chc of thdr (%).0   0   0   10  10  10  20  20  20  30  30  30
Temp............52  50  51  55  60  63  67  68  68  69  67  66
RH..............60  64  65  65  60  53  46  45  42  42  46  50
20 FT wind dir..S   S   SW  SW  SW  W   W   W   W   W   W   W
20 FT wind spd..0   5   5   5   5   5   5   5   5   5   5   5
20 FT wind gust.5               10  10  15  15  15  15  15  15
Ridge wind dir..SW  SW  SW  W   W   W   W   W   SW  SW  SW  W
Ridge wind spd..5   10  15  15  15  15  10  15  15  15  15  10
Mix hgt (kft)...0.5 0.5 0.5 1.5 3.0 4.0 5.5 7.0 8.5 7.0 6.0 6.0
Transp wind dir.S   S   S   SW  SW  SW  SW  W   W   SW  SW  W
Transp wind spd.5   10  5   5   10  10  10  15  15  15  15  15

$$

Forecaster...Moldan
Requested by...RCH
Type of request...WILDFIRE
.TAG 2620698.1/TFX
.DELDT 08/28/26
.FormatterVersion 2.0.0
.EMAIL
mthdc@firenet.gov, nicholas.boucher@usda.gov, stephen.jenkins@usda.gov,
tfx.ops@noaa.gov