Spot Forecast
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
295
FNUS75 KTFX 172027
FWSTFX
Spot Forecast for IA 613...USFS
National Weather Service Great Falls MT
227 PM MDT Mon Aug 17 2026
Forecast is based on forecast start time of 1500 MDT on August 17.
If conditions become unrepresentative...contact the National Weather
Service.
.DISCUSSION...
Scattered thunderstorms are expected through the rest of the evening
with the primary concerns being lightning, gusty and erratic winds,
and small hail. Thunderstorm chances will diminish after sunset with
calmer conditions expected to persist through the mid morning hours.
There will be another chance for thunderstorms Tuesday afternoon and
evening with similar hazard concerns compared to today. Drier
conditions will return Wednesday and Thursday.
.REST OF TODAY...
Sky/weather.........Mostly cloudy (70-80 percent). Chance of
showers and thunderstorms late in the
afternoon, then slight chance of showers and
thunderstorms late in the afternoon.
CWR.................10 percent.
Chance of thunder...27 percent.
Max temperature.....63-68.
Min humidity........36-41 percent.
Wind (20 ft)........
Slope/valley.......Northwest winds 5 to 10 mph. Gusty and erratic
winds expected near thunderstorms.
Ridgetop...........West 10 to 15 mph.
Mixing height.......7500 ft AGL.
Transport winds.....West 15 to 20 mph.
TIME (MDT) 3PM 4PM 5PM
Sky (%).........71 77 69
Weather cov.....CHC SCH SCH
Weather type....RW RW RW
Tstm cov........CHC SCH SCH
CWR.............10 10 10
Chc of thdr (%).30 20 20
Temp............63 64 64
RH..............49 46 44
20 FT wind dir..NW W NW
20 FT wind spd..5 10 10
20 FT wind gust.20 20 20
Ridge wind dir..W W W
Ridge wind spd..10 10 15
Mix hgt (kft)...7.5 7.5 6.5
Transp wind dir.W W W
Transp wind spd.15 20 20
.TONIGHT...
Sky/weather.........Mostly cloudy (65-75 percent). Slight chance of
showers and thunderstorms in the evening.
CWR.................5 percent.
Chance of thunder...19 percent.
Min temperature.....53-58.
Max humidity........50-55 percent.
Wind (20 ft)........
Slope/valley.......Northwest winds 5 to 10 mph shifting to the
west after 3 am. Gusty and erratic winds
expected near thunderstorms in the evening.
Ridgetop...........Northwest 10 to 15 mph decreasing to 0 to 5 mph
in the late evening and overnight, then
shifting to the west after 3 am.
Mixing height.......500 ft AGL.
Transport winds.....Northwest 15 to 20 mph becoming west around 5
mph.
TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM
Sky (%).........78 74 91 70 81 75 73 53 69 59 59 59
Weather cov.....SCH SCH SCH SCH SCH SCH
Weather type....RW RW RW RW RW RW
Tstm cov........SCH SCH SCH SCH SCH SCH
CWR.............10 10 10 10 10 10 10 10 10 10 10 10
Chc of thdr (%).20 20 20 20 20 20 10 10 0 0 0 0
Temp............65 63 61 58 57 56 56 57 56 55 55 55
RH..............43 48 51 54 55 55 55 51 52 53 53 54
20 FT wind dir..NW NW NW NW NW W NW W W W W W
20 FT wind spd..10 10 10 10 5 5 5 5 5 5 5 5
20 FT wind gust.20 15 15 15 10 10 10 10 10 10
Ridge wind dir..W W NW NW NW NW NW W W W W W
Ridge wind spd..15 15 10 10 5 5 0 5 5 10 10 10
Mix hgt (kft)...7.0 5.0 1.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
Transp wind dir.W NW NW W NW NW NW W NW W W W
Transp wind spd.20 15 10 10 5 5 5 5 5 5 5 5
.TUESDAY...
Sky/weather.........Mostly sunny (40-50 percent). Slight chance of
rain showers late in the morning. Slight chance
of thunderstorms early in the afternoon, then
chance of showers and thunderstorms in the
afternoon.
CWR.................5 percent increasing to 25 percent in the
afternoon.
Chance of thunder...34 percent.
Max temperature.....63-68.
Min humidity........37-42 percent.
Wind (20 ft)........
Slope/valley.......West winds around 5 mph shifting to the
northwest late in the morning, then shifting to
the east late in the morning shifting to the
northwest in the afternoon shifting to the
west. Gusty and erratic winds expected near
thunderstorms in the afternoon.
Ridgetop...........West 10 to 15 mph increasing to 15 to 20 mph
late in the afternoon.
Mixing height.......7000 ft AGL.
Transport winds.....West 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 (%).........43 46 28 30 28 48 41 50 58 56 56 62
Weather cov..... SCH SCH CHC CHC CHC CHC CHC
Weather type.... RW RW RW RW RW RW RW
Tstm cov........ SCH CHC CHC CHC CHC CHC
CWR.............10 10 10 10 10 10 30 30 30 30 30 30
Chc of thdr (%).0 0 0 0 0 0 20 30 30 30 30 30
Temp............55 55 56 57 59 61 62 63 63 64 64 65
RH..............52 50 52 53 53 52 50 50 49 44 42 42
20 FT wind dir..W W W W NW E NW NW N NW NW W
20 FT wind spd..5 5 5 5 5 5 5 5 5 5 10 10
20 FT wind gust.10 10 10 15 15 15 15 20 20
Ridge wind dir..W W W W W W W W W W W W
Ridge wind spd..10 10 15 15 15 15 15 15 15 20 15 15
Mix hgt (kft)...0.5 0.5 0.5 1.5 2.5 4.5 5.0 6.0 6.0 6.5 7.0 6.5
Transp wind dir.SW SW W SW W W W W W W NW W
Transp wind spd.5 5 5 5 5 10 10 15 15 15 15 15
$$
Forecaster...Glinskas
Requested by...KEVIN BOOHER
Type of request...WILDFIRE
.TAG 2619870.0/TFX
.DELDT 08/17/26
.FormatterVersion 2.0.0
.EMAIL MTHDC@FIRENET.GOV,tfx.ops@noaa.gov