Spot Forecast
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
649
FNUS75 KTFX 171522
FWSTFX
Spot Forecast for Otter Mountain...USFS
National Weather Service Great Falls MT
922 AM MDT Sun Aug 17 2025
Forecast is based on forecast start time of 0900 MDT on August 17.
If conditions become unrepresentative...contact the National Weather
Service.
.DISCUSSION...
There is a low chance for an isolated light shower through the
morning (15% chance). Better chances for showers and
thunderstorms will be between 1500 to 2000. The main hazards with
storms will be erratic, gusty winds. There is an isolated chance
for localized heavy rainfall if a stronger storms passes directly
over the fire. There will be isolated showers and thunderstorms
Monday, which can be either a "hit or miss" over the fire.
Temperatures warm up Tuesday and Wednesday, with minimum
humidities dropping to the mid to upper teens.
.REST OF TODAY...
Sky/weather.........Mostly sunny (35-45 percent) then becoming
mostly cloudy (70-80 percent). Slight chance of
showers late in the morning, then showers
likely and chance of thunderstorms in the
afternoon.
CWR.................5 percent increasing to 50 percent in the
afternoon.
Chance of thunder...15 percent.
Max temperature.....70-75.
Min humidity........30-35 percent.
Wind (20 ft)........
Slope/valley.......Light winds becoming west around 5 mph in the
late morning and afternoon. Gusty and erratic
winds expected near thunderstorms in the
afternoon.
Ridgetop...........West 10 to 15 mph increasing to southwest
around 25 mph late in the afternoon.
Mixing height.......6500 ft AGL.
Transport winds.....Southwest 5 to 10 mph shifting to the west 10
to 15 mph late in the afternoon.
TIME (MDT) 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........28 28 28 30 40 51 71 81 78
Weather cov.....SCH SCH SCH SCH SCH CHC LKY LKY
Weather type....RW RW RW RW RW RW RW RW
Tstm cov........ SCH SCH CHC CHC CHC
CWR.............10 10 10 50 50 50 50 50 50
Chc of thdr (%).10 10 10 0 15 15 15 15 15
Temp............61 65 67 68 70 70 70 71 67
RH..............62 43 39 35 35 35 39 39 48
20 FT wind dir..W W W W W W W W W
20 FT wind spd..0 5 5 5 5 5 5 5 5
20 FT wind gust.5 10 10 15 15 15 15 15 15
Ridge wind dir..W W W W W W W W SW
Ridge wind spd..10 10 15 15 10 10 10 15 25
Mix hgt (kft)...1.0 2.5 3.5 5.0 6.0 6.5 6.0 4.5 2.5
Transp wind dir.W SW SW W W W W SW W
Transp wind spd.5 10 10 10 10 15 10 10 10
.TONIGHT...
Sky/weather.........Mostly cloudy (60-70 percent) then becoming
partly cloudy (35-45 percent). Chance of
showers and thunderstorms in the evening. Haze
overnight.
CWR.................30 percent decreasing to 0 percent overnight.
Chance of thunder...40 percent.
Min temperature.....51-56.
Max humidity........61-66 percent.
Wind (20 ft)........
Slope/valley.......Southwest winds around 5 mph shifting to the
south early in the evening. Gusty and erratic
winds expected near thunderstorms in the
evening.
Ridgetop...........Southwest 25 to 30 mph becoming west 10 to 15
mph.
Mixing height.......0 ft AGL.
Transport winds.....West around 10 mph shifting to the south in the
evening and overnight, then shifting to the
southwest 10 to 15 mph overnight.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........83 66 82 82 72 57 51 44 48 41 41 35
Weather cov.....SCH CHC SCH SCH DEF DEF DEF DEF
Weather type....RW RW RW RW HAZ HAZ HAZ HAZ
Tstm cov........SCH CHC SCH SCH
CWR.............30 30 30 30 30 30 0 0 0 0 0 0
Chc of thdr (%).40 40 40 20 20 20 0 0 0 0 0 0
Temp............66 66 61 59 58 58 57 56 56 55 54 54
RH..............55 55 66 66 66 66 66 66 64 63 64 64
20 FT wind dir..SW SW S SW S S S S S S S S
20 FT wind spd..5 5 5 5 5 5 10 10 10 10 10 10
20 FT wind gust.10 10 10 10 10 10 15
Ridge wind dir..SW W W W W W W W W W W W
Ridge wind spd..30 25 20 15 10 10 10 10 15 15 15 15
Mix hgt (kft)...2.5 1.0 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.W S S S S S S S S SW S SW
Transp wind spd.10 5 10 10 10 10 10 10 15 10 10 10
.MONDAY...
Sky/weather.........Sunny (10-20 percent) then becoming partly
sunny (60-70 percent). Chance of rain showers
in the afternoon.
CWR.................5 percent.
Chance of thunder...12 percent.
Max temperature.....74-79.
Min humidity........22-27 percent.
Wind (20 ft)........
Slope/valley.......South winds 5 to 10 mph shifting to the west
late in the morning.
Ridgetop...........Southwest 10 to 15 mph.
Mixing height.......8000 ft AGL.
Transport winds.....Southwest 5 to 10 mph increasing to west 15 to
20 mph late in the morning.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........18 18 20 10 10 13 65 65 65 65 65 65
Weather cov..... CHC CHC CHC CHC CHC CHC
Weather type.... RW RW RW RW RW RW
Tstm cov........
CWR.............0 0 0 0 0 0 10 10 10 10 10 10
Chc of thdr (%).0 0 0 10 10 10 10 10 10 10 10 10
Temp............54 53 58 61 67 69 72 73 74 75 76 76
RH..............63 64 59 52 45 41 35 34 32 29 27 26
20 FT wind dir..S S S S SW SW W W W W W W
20 FT wind spd..10 5 5 5 5 5 5 5 5 5 5 5
20 FT wind gust. 10 10 10 10 10 15 15 15 15 15 15
Ridge wind dir..W W SW SW SW SW W W W W W W
Ridge wind spd..15 15 10 10 10 10 10 15 15 15 15 10
Mix hgt (kft)...0.1 0.1 0.5 1.5 3.0 5.0 7.0 8.0 8.0 8.0 8.0 8.0
Transp wind dir.SW S S S SW W W W W W W W
Transp wind spd.10 5 5 5 10 15 15 20 20 20 20 15
$$
Forecaster...Wilson
Requested by...Evan Haugan
Type of request...WILDFIRE
.TAG 2520076.0/TFX
.DELDT 08/17/25
.FormatterVersion 2.0.0
.EMAIL evan.haugan@usda.gov, tfx.ops@noaa.gov