We're holding onto above average temperatures with high pressure over the west. We're also still bringing in smoke and haze from the west. We have an Air Quality Alert issued by the Idaho DEQ, until further notice. We'll begin to see a chance by this Friday and Saturday, with a low pressure system moving in from the west. This Friday night and Saturday, we'll have a chance of showers and more wind, with dropping temperatures.
AN AIR QUALITY FORECAST AND CAUTION FROM THE IDAHO DEPARTMENT
OF ENVIRONMENTAL QUALITY REMAINS IN EFFECT…
Due to wildfire smoke, the air quality remains unhealthy for
sensitive groups in Bonneville, Butte, Clark, Custer, Fremont,
Jefferson, Madison, and Teton counties of Idaho. Air quality is
expected to fluctuate between UNHEALTHY FOR SENSITIVE GROUPS and
UNHEALTHY for all. This advisory will remain in effect until air
quality has significantly improved.
FIRE WEATHER WATCH IN EFFECT FROM 1 PM THURSDAY AFTERNOON
THROUGH 9 PM FRIDAY:
The National Weather Service in Pocatello has issued a Fire
Weather Watch for gusty winds, low relative humidity, a Haines
Index of 6, and poor overnight humidity recovery for all of
southeast Idaho, which is in effect from 1 PM Thursday afternoon
through 9 PM Friday evening.
- AFFECTED AREA…Fire Weather Zone 410 covering the Upper Snake
River Valley/Idaho Falls BLM, Fire Weather Zone 411 covering the
Centennial Mountains and Snake River Range/Targhee NF, Fire
Weather Zone 413 covering the Caribou Range/Caribou NF, Fire
Weather Zone 422 covering the Sawtooth Range/Northern Sawtooth
NF, Fire Weather Zone 425 covering the Middle Snake River
Valley/Twin Falls BLM north of the Snake River, Fire Weather
Zone 427 covering Goose Creek and Raft River Valley/Southern
Sawtooth NF/Twin Falls BLM south of the Snake River, Fire
Weather Zone 475 covering the East Salmon River Mountains/Salmon
NF, and Fire Weather Zone 476 covering the Lemhi and Lost River
- WINDS…South to southwest 10 to 15 MPH with gusts up to 25 MPH
Thursday, and south to southwest 10 to 20 MPH with gusts up to
30 MPH Friday. The strongest winds will likely occur each
afternoon and evening.
- RELATIVE HUMIDITY…Minimum values of 8 to 18 percent Thursday,
and 14 to 23 percent Friday. Overnight humidity recovery will
remain very poor at mid to upper slopes, likely not rising above
25 percent in many areas.
- IMPACTS…While raw wind and humidity values may not quite reach
traditional Red Flag criteria for all areas both days, the
combination of critical to near-critical humidity with an
increase in wind, Haines Index of 6, poor overnight humidity
recovery, very dry fuels, and recent fire behavior suggest a
critical fire weather pattern will be in place Thursday and
Friday. New and preexisting fires may spread rapidly.