A dry, windy, and possibly stormy pattern is setting up across much of the inland Northwest and western Great Basin Thursday, bringing critically dangerous fire conditions to the region.
Fire Weather Warnings are in effect across much of central and northeastern Oregon, far northern California, parts of eastern Idaho, and stretching into a large swath of Montana through Thursday night. Similar warnings are also in effect for northwestern and northeastern Wyoming and western South Dakota. NOAA's Storm Prediction Center says an area of southwestern Montana, eastern Idaho and south-central Oregon carry the most critical danger area for wildfire.
9/9 5 AM PDT: An active fire weather day is likely across parts of the interior West this afternoon/tonight. Widespread dry and breezy conditions are expected from NV to the northern High Plains. Isolated to scattered storms producing little to no rainfall also appear probable. pic.twitter.com/gWa3bPF3jJ— NWS Storm Prediction Center (@NWSSPC) September 9, 2021
At issue is a trough of low pressure that will carry enough atmospheric instability to bring gusty winds and some thunderstorms at high altitudes. However, with such dry air at the surface, the storm's rainfall is expected to evaporate before reaching the ground.
That brings worst case weather scenarios to the parched region, with potential thunderstorms that can bring abundant fire-sparking lightning -- but no rainfall to wet things down -- and gusty winds to fan the flames of any fires that do begin. Gusts could reach as high as 30-40 mph and relative humidity levels in the warning areas are around 15-20 percent.
Red Flag Warning for portions of the northwest from noon to 8 PM today. A Fire Weather Watch is in effect for portions of central & southern areas Friday afternoon & evening. For more details: https://t.co/Yvvgwg8fLS— NWS Riverton (@NWSRiverton) September 9, 2021
Please make sure your campfire is out! #wywx #fire pic.twitter.com/9Hrk3lAuj7
Meanwhile, Fire Weather Watches, meaning dangerous wildfire conditions are possible, stretch across much of the rest of northern California, including the Sacramento and north Bay Area and into northern Nevada, including the Reno and Lake Tahoe areas.
The Caldor Fire, which is still burning near the Lake Tahoe area, remains about 50% contained, but firefighters have made enough progress to allow residents in South Lake Tahoe to return home this past weekend, according to the Associated Press. The Dixie Fire to the north, California's 2nd largest fire on record, is 59% contained as it has so far burned over 1,400 square miles.
Those pair as well as 12 other major wildfires burning in the area are continuing to blanket much of the inland West with smoke.
Another day of smoky conditions across the region. We do expect some improvement tomorrow with passage of a cold front. Showers will accompany the front followed by isolated thunderstorms with heavy rain and gusty winds in the afternoon/evening. #idwx #orwx pic.twitter.com/DPAI2MuFCi— NWS Boise (@NWSBoise) September 9, 2021
Air Quality Alerts remain in effect across much of southern and central Oregon, as well as southern Idaho and parts of Montana, Wyoming, northern Colorado and three counties in central Washington.
The fire weather forecast for Friday is a little more favorable, though elevated risk of wildfire is expected to continue in Wyoming and the western Nevada and Lake Tahoe area.