559
FNUS75 KBOI 191325
FWSBOI

Spot Forecast for Tartar Fire...FS
National Weather Service Boise ID
725 AM MDT Wed Aug 19 2026

Forecast is based on forecast start time of 0800 MDT on August 19.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office at (208)334-9060, if you have questions
or concerns with this forecast.

...HEAT ADVISORY IN EFFECT FROM NOON THURSDAY TO 9 PM MDT
FRIDAY...

...HOT THROUGH SATURDAY...
...WINDS AND THUNDERSTORM CHANCES INCREASE SATURDAY...

.DISCUSSION...
Warming trend through Friday, with max temperatures near 90
degrees Thursday and Friday. Winds each day are fairly mild,
especially on east-south aspects where daily upslope and nocturnal
downslope winds can be expected. Drainage winds off higher
terrain to the north and west will keep a 10 to 15 mph gust
overnight, especially on ridges. This weekend, monsoonal moisture
increases minimum RHs into the 20s and maximum RHs into the
40/50s, while the system itself brings strong 30 mph southwesterly
gusts on Saturday. Thunder chances near the fire are 10%, with
most of the storm activity likely to be well east of the fire.

.REST OF TODAY...

Sky/weather.........Mostly sunny.
Max temperature.....80 to 88.
Min humidity........12 to 16 percent.
CWR.................0 percent.
Wind - 20 foot......Generally west-northwest 3 to 8 mph, winds
                    eastern and southern aspect slopes will be
                    lighter and upslope.
Mixing height.......7500 ft AGL.
Transport winds.....West around 5 mph.
Ventilation Index...375 fair.

.TONIGHT...

Sky/weather.........Mostly clear.
Min temperature.....62 to 73.
Max humidity........18 to 28 percent.
CWR.................0 percent.
Wind - 20 foot......North-northeast 4 to 8 mph, with gusts on
                    higher terrain up to 14 mph.
Mixing height.......100 ft AGL.
Transport winds.....North around 10 mph.
Ventilation Index...10 poor.

.THURSDAY...

Sky/weather.........Sunny.
Max temperature.....82 to 97.
Min humidity........10 to 17 percent.
CWR.................0 percent.
Wind - 20 foot......Northeast 2 to 8 mph in the morning shifting
                    to the south 6 to 10 mph in the afternoon.
                    Gusts up to 16 mph.
Mixing height.......8500 ft AGL.
Transport winds.....Southwest around 10 mph.
Ventilation Index...850 excellent.

$$
Forecaster...Macfarlane
Requested by...Shawn Donnelly
Type of request...WILDFIRE
.TAG 2619434.8/BOI
.DELDT 08/19/26
.FormatterVersion 2.0.0
.EMAIL sdonnell18@gmail.com,alexjpena60@gmail.com