Spot Forecast
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
824
FNUS75 KTFX 181151
FWSTFX
Spot Forecast for Gill Gulch Fire...USFS
National Weather Service Great Falls MT
551 AM MDT Mon Aug 18 2025
Forecast is based on forecast start time of 0600 MDT on August 18.
If conditions become unrepresentative...contact the National Weather
Service.
.DISCUSSION...
Heat begins to build today as upper level ridging moves into the
area. Even with this ridge building in, there will still be a low
(20%) chance of a shower or thunderstorm this afternoon and
evening, particularly between 1600 and 2000. Any shower or
thunderstorm will have the potential to produce some gusty outflow
winds that can travel away from the parent storm, so be alert
for sudden changes in wind direction and speed this afternoon and
evening. Dry and warmer weather is expected for Tuesday after a
night of poor RH recovery Monday night. A ridge breakdown is
expected on Wednesday and Thursday, though there remains
uncertainty as to how exactly that will play out.
.TODAY...
Sky/weather.........Mostly sunny (30-40 percent). Slight chance of
showers and thunderstorms late in the
afternoon.
CWR.................5 percent.
Chance of thunder...20 percent.
Max temperature.....73-78.
Min humidity........26-31 percent.
Wind (20 ft)........
Slope/valley.......South winds around 5 mph shifting to the
southwest late in the morning. Gusty and
erratic winds expected near thunderstorms late
in the afternoon.
Ridgetop...........Southwest 10 to 15 mph shifting to the west
around 20 mph late in the afternoon.
Mixing height.......8000 ft AGL.
Transport winds.....South 5 to 10 mph increasing to southwest 15 to
20 mph in the afternoon.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........26 54 44 41 38 35 21 15 14 25 25 45
Weather cov..... SCH SCH SCH
Weather type.... RW RW RW
Tstm cov........ SCH SCH SCH
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 20 20
Temp............53 53 54 55 60 64 67 69 71 73 74 74
RH..............73 71 68 66 58 50 42 40 36 32 30 29
20 FT wind dir..S S S S SW SW SW W W W W W
20 FT wind spd..5 5 5 5 5 5 5 5 5 10 5 5
20 FT wind gust. 10 10 10 10 15 15 15 20 20 15
Ridge wind dir..SW SW SW SW SW SW SW SW W W W W
Ridge wind spd..10 10 10 10 10 10 15 15 15 15 15 20
Mix hgt (kft)...0.1 0.1 0.1 0.1 1.0 2.0 5.0 6.5 7.0 8.0 7.5 5.0
Transp wind dir.S S S S S SW W SW W SW W SW
Transp wind spd.5 5 5 5 5 10 15 20 20 20 20 15
.TONIGHT...
Sky/weather.........Partly cloudy (20-30 percent). Slight chance of
showers and thunderstorms early in the evening.
CWR.................0 percent.
Chance of thunder...3 percent.
Min temperature.....55-60.
Max humidity........49-54 percent.
Wind (20 ft)........
Slope/valley.......West winds around 5 mph shifting to the south
early in the evening. Gusty and erratic winds
expected near thunderstorms early in the
evening.
Ridgetop...........Southwest 15 to 20 mph decreasing to around 10
mph early in the evening, then shifting to the
south overnight.
Mixing height.......0 ft AGL.
Transport winds.....Southwest 10 to 15 mph decreasing to around 5
mph early in the evening, then shifting to the
southeast in the late evening and overnight.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........25 40 37 30 41 13 12 15 10 13 13 10
Weather cov.....SCH SCH SCH
Weather type....RW RW RW
Tstm cov........SCH SCH SCH
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............75 73 70 65 63 62 60 60 60 59 59 59
RH..............30 32 38 45 48 50 51 50 51 51 52 52
20 FT wind dir..W SW S SE SE SE SE S S S S S
20 FT wind spd..5 5 5 5 5 5 5 5 5 5 5 5
20 FT wind gust.15 15 10 10 10 10 10 10
Ridge wind dir..W SW SW SW SW S SE S S S S S
Ridge wind spd..20 15 10 10 10 10 10 10 10 10 10 10
Mix hgt (kft)...3.5 3.5 0.5 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Transp wind dir.SW SW SW S SE SE SE SE SE SE SE S
Transp wind spd.15 10 5 5 5 5 5 5 5 5 5 5
.TUESDAY...
Sky/weather.........Sunny (10-20 percent).
CWR.................0 percent.
Chance of thunder...2 percent.
Max temperature.....80-85.
Min humidity........13-18 percent.
Wind (20 ft)........
Slope/valley.......Southwest winds around 5 mph shifting to the
west late in the afternoon.
Ridgetop...........Southwest around 10 mph shifting to the west
late in the afternoon.
Mixing height.......9000 ft AGL.
Transport winds.....South 5 to 10 mph increasing to southwest 15 to
20 mph in the afternoon.
TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
Sky (%).........9 22 9 6 3 4 5 5 5 11 11 11
Weather cov.....
Weather type....
Tstm cov........
CWR.............0 0 0 0 0 0 0 0 0 0 0 0
Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0
Temp............57 59 60 63 68 72 75 78 79 81 82 82
RH..............51 51 50 48 40 34 30 26 23 21 18 17
20 FT wind dir..S S S S S SW SW SW SW W W W
20 FT wind spd..5 5 5 5 5 5 5 5 5 5 5 5
20 FT wind gust. 10 10 10 15 15 15 15 15 15
Ridge wind dir..S S S S S SW SW SW SW SW W W
Ridge wind spd..10 10 10 10 10 10 10 10 10 10 10 5
Mix hgt (kft)...0.1 0.1 0.1 0.1 1.5 3.5 5.5 7.0 8.0 9.0 9.0 9.0
Transp wind dir.S S S SW SW SW SW SW SW SW SW W
Transp wind spd.5 5 5 5 5 10 15 15 20 20 15 15
$$
Forecaster...Ludwig
Requested by...Hannah Pinkerton
Type of request...WILDFIRE
.TAG 2519519.9/TFX
.DELDT 08/18/25
.FormatterVersion 2.0.0
.EMAIL jarel.kurtz@usda.gov,hannah.pinkerton@usda.gov,todd.a.burbridge@usda.gov,jason.l.gilbert@usda.gov,nicholas.boucher@usda.gov, tfx.ops@noaa.gov