FNUS75 KBYZ 191518 FWSBYZ Spot Forecast for North Derby RX...USFS National Weather Service Billings MT 918 AM MDT Thu Mar 19 2026 Forecast is based on ignition time of 0800 MDT on March 23. If conditions become unrepresentative...contact the National Weather Service. Please contact our office if you have questions or concerns with this forecast. .DISCUSSION... Warm and dry conditions will persist through Saturday when a frontal passage is expected. There is a 40% chance for a wetting rain late Saturday afternoon through the evening. Min RHs will generally be in 20-30% range with moderate overnight recoveries. Little to no chances for precipitation through the forecast period, but a 10-20% chance for precipitation exists Tuesday night. there is still a lot of uncertainty with this potential. The potential for strong winds does look to pick up early Wednesday. There is currently about a 50% chance for gusts to 60 mph Wednesday. .MONDAY... Sky/weather.........Mostly cloudy. CWR.................2 percent. Chance of lightning.1 percent. Max temperature.....56-60. Min humidity........25-29 percent. Wind (20 ft)........ Slope/valley.......Southwest winds up to 10 mph shifting to the northeast in the afternoon with gusts 15 to 20 mph. Ridgetop...........West 15 mph Mixing height.......Increasing to 4500 ft AGL in the afternoon. Transport winds.....Southwest 10 mph TIME (MDT) 9 AM 12 PM 3 PM Sky (%).........72 67 71 Weather cov..... Weather type.... Tstm cov........ Chc of ltng (%).0 0 0 Temp............45 54 57 RH..............40 30 27 20 FT wind. SW 5G8 NE 5G14 N 8G18 .MONDAY NIGHT... Sky/weather.........Mostly cloudy. CWR.................3 percent. Chance of lightning.0 percent. Min temperature.....40-44. Max humidity........49-53 percent. Wind (20 ft)........ Slope/valley.......North winds 5 to 7 mph shifting to the southwest 5 to 6 mph in the late evening and overnight. Ridgetop...........West 20 mph Mixing height.......Decreasing to 700 ft AGL overnight. Transport winds.....Southwest 12 mph. TIME (MDT) 6 PM 9 PM MID 3 AM Sky (%).........80 75 73 71 Weather cov..... Weather type.... Tstm cov........ Chc of ltng (%).0 0 0 0 Temp............55 49 47 44 RH..............32 42 45 49 20 FT wind. N 7G14 SW 6G10 SW 6G8 SW 6G8 .TUESDAY... Sky/weather.........Mostly cloudy. CWR.................4 percent. Chance of lightning.2 percent. Max temperature.....65-69. Min humidity........26-30 percent. Wind (20 ft)........ Slope/valley.......Southwest winds 5 to 12 mph. Gusts up to 30 mph in the afternoon. Ridgetop...........West 28 mph Mixing height.......Increasing to 4000 t AGL in the afternoon. Transport winds.....Southwest 25 mph. TIME (MDT) 6 AM 9 AM NOON 3 PM Sky (%).........77 73 73 71 Weather cov..... Weather type....NONE NONE NONE NONE Tstm cov........ Chc of ltng (%).0 0 0 0 Temp............44 50 61 66 RH..............51 44 33 28 20 FT wind......SW 6G10 SW 7G14 SW 10G23 SW 12G27 $$ Forecaster...Stetzer Requested by...Greg Oyler Type of request...PRESCRIBED .TAG 2606530.0/BYZ .DELDT 03/19/26 .FormatterVersion 2.0.0 .EMAIL gregory.oyler@usda.gov