FNUS75 KBYZ 181503

FWSBYZ



Spot Forecast for ROADSIDE HWY 1...BIA

National Weather Service Billings MT

903 AM MDT Sat Jul 18 2026



Forecast is based on forecast start time of 0900 MDT on July 18. 

If conditions become unrepresentative...contact the National Weather

Service.



Please contact our office if you have questions

or concerns with this forecast.



.DISCUSSION...



Warm conditions will prevail at the fire site today with a slight

chance of afternoon and evening showers and thunderstorms after 

1500 MDT. Gusty and erratic winds to 40 mph are possible with 

thunderstorms. Look for southwest or variable winds to shift to 

the northwest by this afternoon. Moderate to good RH recoveries 

can be expected tonight with southerly winds. A weak frontal 

passage on Sunday brings northwest winds and additional shower and

thunderstorm chances in the afternoon and evening.



.REST OF TODAY...



Sky/weather.........Mostly sunny. Slight chance of showers

                    and thunderstorms after 1500 MDT. 

CWR.................10 percent. 

Chance of lightning.15 percent. 

Max temperature.....92-97. 

Min humidity........25-30 percent. 

Wind (20 ft)........ 

 Slope/valley.......Southwest winds 3 to 6 mph or variable

                    at times this morning shifting to the 

                    northwest 5 to 10 mph by the afternoon.

                    Gusty and erratic winds expected near

                    thunderstorms. 

 Ridgetop...........Southwest 4 to 8 mph or variable at

                    times this morning shifting to the

                    northwest 6 to 12 mph by this afternoon. 

Mixing height.......Increasing to 7900 ft AGL in the afternoon. 

Transport winds.....West around 10 mph. 



.TONIGHT...



Sky/weather.........Partly cloudy. Slight chance of showers

                    and thunderstorms through 2400 MDT.

CWR.................10 percent. 

Chance of lightning.15 percent. 

Min temperature.....63-68. 

Max humidity........75-80 percent. 

Wind (20 ft)........

 Slope/valley.......Southeast winds 5 to 11 mph this evening

                    becoming southwest overnight. Gusty

                    and erratic winds expected near thunderstorms.

 Ridgetop...........South to southeast 7 to 14 mph this 

                    evening becoming southwest 6 to 12 mph

                    overnight. 

Mixing height.......Decreasing to 400 ft AGL overnight. 

Transport winds.....South around 14 mph. 



.SUNDAY...



Sky/weather.........Sunny becoming partly cloudy in the afternoon.

                    Slight chance of showers and thunderstorms

                    after 1500 MDT. 

CWR.................15 percent. 

Chance of lightning.20 percent. 

Max temperature.....95-99. 

Min humidity........20-25 percent. 

Wind (20 ft)........ 

 Slope/valley.......Northwest winds 7 to 13 mph. Gusty and erratic

                    winds expected near thunderstorms.

 Ridgetop...........Northwest 8 to 16 mph. 

Mixing height.......Increasing to 13600 ft AGL in the afternoon. 

Transport winds.....Northwest around 15 mph. 



$$

Forecaster...Palmquist

Requested by...COSTA

Type of request...WILDFIRE

.TAG 2617666.0/BYZ

.DELDT 07/18/26

.FormatterVersion 2.0.0

.EMAIL GARRETCOSTA71@GMAIL.COM,MTBDC@FIRENET.GOV