Cloud cover and showers today

The closed low-pressure system will bring widespread showers and thunderstorms from Sandpoint south to the Central Mountains and over the Eastern Highlands. Showers are likely over the Southeast Highlands. There is a slight chance to a chance for showers and thunderstorms over the Treasure Valley and Upper Snake River Plain in the south and over the panhandle north of Sandpoint. Winds in the north will be from the south-southwest to west-southwest at 5-15 mph with gusts up to 20 mph. Winds in the south will be from the northwest to southwest at 5-20 mph in the afternoon with gusts up to 30 mph from the Magic Valley east. 

The active weather pattern will continue to result in minimal wildfire activity over much of Idaho, while there has some minor fire growth on fires to the west. The central area of the state could see some lofted haze today but generally, smoke impacts will continue to be limited to areas immediately downwind of local fires. Smoke is expected to settle in adjacent mountain valleys overnight. 

GOES-17 West Satellite Imagery from RAMMB/CIRA from 8:30-10:20 am MDT shows the closed low-pressure bringing cloud cover and showers to Idaho.

Rainy day for central and south Idaho

Air quality today is forecast to be Good.

The approaching closed low pressure system will slowly move into the Pacific Northwest, and the associated moisture will bring a chance for afternoon showers and thunderstorms over all of south Idaho and up into the prairies of central Idaho. Showers and thunderstorms are likely over the Central Mountains and the Eastern, Southeast, and Southern Highlands. Isolated showers are possible along the Clearwater River. Winds in the south will be from the northwest to southeast at 5-15 mph in the afternoon with gusts up to 25 mph from the Magic Valley east. In the north, winds will be from the northeast to northwest at 5-15 mph with gusts up to 20 mph in the vicinity of Grangeville in the afternoon. Higher gusts are possible near any thunderstorm activity. 

The active weather pattern will continue to result in minimal fire activity over much of the region. Smoke impacts will continue to be limited to areas immediately downwind of local fires. Smoke is expected to settle in adjacent mountain valleys overnight. 

MODIS Terra Satellite image from yesterday, 9/20, shows some smoke impacts downwind of local fires. 

Clear skies finally

Air quality today is forecast to be Good to Moderate.

An approaching low-pressure system will stall over California today, and north Idaho will be under split flow aloft while south Idaho will be under southwest flow aloft. In the south, winds will be from the northwest to south-southwest at 5-15 mph in the afternoon with gusts up to 25 mph, mainly from the Magic Valley east. In the north, winds will be from the northeast at 5-15 mph with northerly winds over Lewiston. 

The continued active weather pattern will result in minimal fire activity over much of the region. Smoke impacts will be light and limited to areas immediately downwind of local fires. 

MODIS Terra Satellite image from yesterday, 9/19, shows clear skies across the state. 

Hazy today

Much of Idaho will be under southwest flow aloft as an approaching low pressure system stalls just off the coast of northern California. Isolated showers and thunderstorms are possible over the far northern panhandle. Over north Idaho, winds will be from the southwest to northwest at 5-10 mph with gusts up to 15 mph over the Panhandle in the afternoon. Winds in the vicinity of Grangeville will be from the northeast. Over south Idaho, winds will be from the southeast at 2-8 mph over the Treasure Valley and from the south to southwest at 10-20 mph elsewhere in the afternoon with gusts up to 25 mph over south-central and eastern Idaho. 

Expect hazy conditions and light smoke impacts primarily across Central and North Idaho with some minor impacts all along the Idaho/Oregon border through Tuesday morning. Smoke impacts will be heavily dependent on fire activity. Some areas immediately downwind of fires could see impacts, especially overnight as smoke settles into mountain valleys.  

HRRR-Smoke Near Surface Smoke initialized at 06Z (12am MDT) and valid at 6pm MDT shows light smoke impacts along the OR/ID border and further north across Central and Northern Idaho.  

Air Quality Advisory Lifted for the Nez Perce Reservation