FNUS75 KTFX 181000 FWSTFX Spot Forecast for Jericho Creek Fire...USFS National Weather Service Great Falls MT 400 AM MDT Mon May 18 2026 Forecast is based on forecast start time of 0600 MDT on May 18. If conditions become unrepresentative...contact the National Weather Service. .DISCUSSION... One final day of well below normal temperatures is expected across the incident area as cool, northwest flow remains in place in wake of the departing disturbance. Upper level ridging over the Eastern Pacific will begin to amplify through the remainder of the week, which will allow temperatures to moderate to near normal across the Northern Rockies despite persistent northwest flow aloft. Daily chances for showers, and occasional thunderstorms, will exist throughout the work week, with the best opportunity for wetting precipitation arriving Wednesday morning through Thursday morning. At this time the potential for 0.1" or greater of precipitation over this timeframe is a 70% chance, with a 55% chance for 0.25" and a 35% chance for 0.5". .TODAY... Sky/weather.........Mostly sunny (45-55 percent). Slight chance of snow late in the afternoon. CWR.................5 percent. Chance of thunder...16 percent. Max temperature.....41-46. Min humidity........39-44 percent. Wind (20 ft)........ Slope/valley.......Northwest winds around 3 to 8 mph shifting to the north in the late morning and afternoon. Ridgetop...........North 5 to 10 mph. Mixing height.......6500 ft AGL. Transport winds.....North 10 to 15 mph. TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM Sky (%).........56 51 47 42 46 49 53 51 50 48 49 49 Weather cov..... SCH SCH Weather type.... SN SN Tstm cov........ CWR.............10 10 10 10 10 10 10 10 10 10 10 10 Chc of thdr (%).0 0 0 0 0 0 10 10 10 10 20 10 Temp............22 24 26 28 32 35 36 38 40 41 42 43 RH..............92 86 78 73 67 61 56 52 48 45 44 44 20 FT wind dir..W NW NW N N N NE NE N N N NE 20 FT wind spd..5 5 5 5 5 10 10 10 10 10 5 5 20 FT wind gust. 10 10 15 15 15 15 15 15 15 15 15 Ridge wind dir..N N N N N N N N N N NW NW Ridge wind spd..10 10 10 10 10 10 10 5 5 5 5 5 Mix hgt (kft)...1.0 1.0 2.5 3.5 4.5 5.0 5.5 6.0 6.5 6.5 6.5 6.5 Transp wind dir.N N N N N N N N N N N N Transp wind spd.10 10 15 15 15 15 15 15 15 15 10 10 .TONIGHT... Sky/weather.........Partly cloudy (25-35 percent). Slight chance of snow early in the evening. CWR.................5 percent. Chance of thunder...7 percent. Min temperature.....21-26. Max humidity........80-85 percent. Wind (20 ft)........ Slope/valley.......Northeast winds 3 to 8 mph shifting to the south early in the evening, then shifting to the southwest late in the evening. Ridgetop...........West around 5 to 10 mph increasing to 10 to 15 mph. Mixing height.......500 ft AGL. Transport winds.....North 5 to 10 mph shifting to the west late in the evening, then shifting to the south late in the evening shifting to the west overnight. TIME (MDT) 6PM 7PM 8PM 9PM 10P 11P MID 1AM 2AM 3AM 4AM 5AM Sky (%).........50 41 32 23 19 16 12 14 16 18 21 24 Weather cov.....SCH Weather type....SN Tstm cov........ CWR.............10 10 10 10 10 10 0 00 0 0 0 Chc of thdr (%).10 10 10 0 0 0 0 0 0 0 0 0 Temp............42 40 38 33 31 29 28 28 27 25 25 25 RH..............44 46 56 68 75 79 83 80 82 84 84 84 20 FT wind dir..NE E S S S SW SW SW SW SW SW SW 20 FT wind spd..5 5 5 5 5 5 5 5 5 5 5 5 20 FT wind gust.10 10 10 10 10 10 10 10 10 Ridge wind dir..W W SW SW SW W W W W W W W Ridge wind spd..5 5 0 0 5 10 15 15 15 15 15 15 Mix hgt (kft)...5.0 3.5 2.0 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Transp wind dir.N N NW W S SW SW W W W W W Transp wind spd.10 5 5 5 5 5 5 10 10 10 10 10 .TUESDAY... Sky/weather.........Mostly sunny (35-45 percent). Slight chance of snow late in the morning. Slight chance of rain late in the morning, then chance of rain late in the afternoon. CWR.................5 percent. Chance of thunder...2 percent. Max temperature.....50-55. Min humidity........35-40 percent. Wind (20 ft)........ Slope/valley.......West winds 5 to 10 mph. Ridgetop...........West 15 to 20 mph. Mixing height.......9000 ft AGL. Transport winds.....West 10 to 15 mph. TIME (MDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM Sky (%).........32 32 32 38 38 38 46 46 46 50 50 50 Weather cov..... SCH SCH SCH SCH SCH CHC CHC Weather type.... RS RN RN RN RN RN RN Tstm cov........ CWR.............10 10 10 10 10 10 10 10 10 10 10 10 Chc of thdr (%).0 0 0 0 0 0 0 0 0 0 0 0 Temp............24 27 30 35 42 45 46 47 49 50 50 52 RH..............85 76 65 57 52 46 44 42 40 40 40 40 20 FT wind dir..SW W W W W W W W W W W W 20 FT wind spd..5 5 5 10 10 10 10 10 10 10 10 10 20 FT wind gust.10 10 10 15 15 15 20 20 20 20 20 20 Ridge wind dir..W W W W W W W W W W W W Ridge wind spd..15 15 15 15 15 15 15 15 15 20 20 20 Mix hgt (kft)...0.5 1.0 2.5 4.0 5.5 6.0 7.0 8.0 8.5 8.5 8.5 9.0 Transp wind dir.W W W W W W W W W W W W Transp wind spd.10 10 15 15 15 15 15 15 15 15 15 15 $$ Forecaster...Moldan Requested by...Will menning Type of request...WILDFIRE .TAG 2613863.1/TFX .DELDT 05/18/26 .FormatterVersion 2.0.0 .EMAIL william.menning@usda.gov,scott.nelson@dnr.wa.gov,MTHDC@firenet.gov,megan.nolte@usda.gov, tfx.ops@noaa.gov