Air Quality Report, September 12, 2013
Incident: Rim Fire Wildfire
Air Quality Report
Thursday September 12 2013 Rim Fire Stanislaus National Forest
Yesterday September 11 2013
The Rim Fire burned approximately 250 acres almost entirely within the containment lines. It is currently 255 560 acres. Smoke production is primarily the result of heavy fuels that can continue to burn for several days within the fire area. Cloud cover and higher humidity helped to moderate fire activity. Most areas saw improved air quality from the previous days.
Thursday September 12 2013
Light downslope winds and a moderate inversion caused smoke to drain down the Clavey and Tuolumne River Drainages. Smoke impacts in the communities of Pinecrest Columbia Groveland Greeley Hill La Grange El Portal and Mariposa will be about the same as yesterday reaching their highest intensity early in the day and improving by afternoon. With transport winds still fairly light smoke impacts will remain localized. Evening impacts can be expected again for Tuolumne Meadows and Yosemite Valley with northwest ridgetop winds forecast. Diurnal upslope/upcanyon flows will be the dominant winds. A slightly chance of thunderstorms over the Sierras again today could aid smoke dispersion some in the late afternoon. Easterly winds will remain fairly light again tonight keeping impacts localized and probably not extending into the San Joaquin Valley.
Friday September 13 2013
Similar morning impacts can be expected in areas where the inversion will cause smoke to settle. Transport winds may be a little lighter taking longer to clear smoke from foothill communities. Afternoon thunderstorm chances are lower than for Thursday. Northwesterly ridgetop winds will continue to send smoke toward the Yosemite region which is likely to settle in the Tuolumne Meadows and Yosemite Valley basins in the evening. Nighttime easterlies will strengthen a bit possibly moving smoke a little further into the San Joaquin Valley.
Long term Outlook
Conditions remain very similar Saturday but start to transition on Sunday into Monday as a low pressure trough moves through. Winds will become southwesterly and temperatures decrease probably beginning sometime Sunday and lasting into early next week. This should give the areas south and west of the fire some clean air and depending on the amount of remaining emissions could return some smoke to areas north and east of the fire.