289
FNUS75 KBYZ 190231
FWSBYZ

Spot Forecast for South Brewer...BLM
National Weather Service Billings MT
831 PM MDT Mon Aug 18 2025

Forecast is based on forecast start time of 2100 MDT on August 18.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office if you have questions
or concerns with this forecast.

...HEAT ADVISORY IN EFFECT FROM 9 AM TUESDAY TO 9 PM MDT
WEDNESDAY...

...Hot and dry through Wednesday...
...Low level jet Tuesday night into Wednesday morning...

Southeast winds will prevail at the fire site overnight with
moderate to good RH recoveries. Conditions trend hotter and drier
for Tuesday. There is a small chance of a shower or thunderstorm
Tuesday afternoon and evening. A low level jet will keep ridgetops
breezy Tuesday night and help aid in ventilation. As a result, RH
recoveries will only be moderate. Hot, dry and unstable
conditions can be expected for Wednesday.

.DISCUSSION...

.REST OF TONIGHT...

Sky/weather.........Mostly clear.
CWR.................0 percent.
Chance of lightning.2 percent.
Min temperature.....64-68.
Max humidity........67-72 percent.
Wind (20 ft)........
 Slope/valley.......Southeast winds 5 to 9 mph.
 Ridgetop...........Southeast 8 to 16 mph.
Mixing height.......Decreasing to 200 ft AGL overnight.
Transport winds.....Southeast around 15 mph.

.TUESDAY...

Sky/weather.........Sunny becoming partly cloudy in the afternoon.
                    Slight chance of showers and thunderstorms after
                    1500 MDT.
CWR.................5 percent.
Chance of lightning.15 percent.
Max temperature.....90-94.
Min humidity........22-27 percent.
Wind (20 ft)........
 Slope/valley.......Southeast winds 6 to 12 mph in the morning
                    increasing to 10 to 18 mph in the afternoon.
                    Gusty and erratic winds near thunderstorms.
 Ridgetop...........South 8 to 16 mph increasing to 10 to 20 mph
                    in the afternoon.
Mixing height.......Increasing to 8200 ft AGL in the afternoon.
Transport winds.....Southeast around 18 mph.

.TUESDAY NIGHT...

Sky/weather.........Mostly clear. Slight chance of showers and
                    thunderstorms before 2000 MDT.
CWR.................5 percent.
Chance of lightning.15 percent.
Min temperature.....68-72.
Max humidity........53-58 percent.
Wind (20 ft)........
 Slope/valley.......Southeast winds 8 to 16 mph with gusts to
                    around 25 mph. Gusty and erratic winds
                    near thunderstorms.
 Ridgetop...........South 15 to 30 mph.
Mixing height.......Decreasing to 200 ft AGL overnight.
Transport winds.....South around 25 mph.

.WEDNESDAY...

Sky/weather.........Sunny.
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....95-99.
Min humidity........18-22 percent.
Wind (20 ft)........
 Slope/valley.......South winds 7 to 14 mph with gusts to around 20
                    mph.
 Ridgetop...........South 10 to 20 mph.
Mixing height.......Increasing to 11000 ft AGL in the afternoon.
Transport winds.....South around 20 mph.

$$
Forecaster...Palmquist
Requested by...Connor Adkins
Type of request...WILDFIRE
.TAG 2520190.0/BYZ
.DELDT 08/18/25
.FormatterVersion 2.0.0
.EMAIL MTMCC@firenet.gov