Air Quality Update--September 9, 2013
Incident: Rim Fire Wildfire
Yesterday September 8 2013
The Rim Fire burned approximately 3 000 acres mostly within the containment lines. It is currently 253 332 acres. Easterly winds pushed smoke into the central valley where it was trapped under a weak inversion. Transport winds in the fire area were very weak so smoke did not clear from many areas until well into the afternoon. Northwest transport winds developed in the afternoon pushing smoke into the Yosemite and San Joaquin Valley regions. Areas north and east of the fire had their first break from smoke in several days.
Monday September 9 2013
Easterly winds overnight pushed the Rim fire smoke into the San Joaquin Valley. Morning smoke is spread throughout the region with the heaviest impacts in Columbia Le Grange Greeley Hill Groveland El Portal and Tuolumne Meadows. Communities in the San Joaquin Valley may see further impacts as the inversion breaks and smoke begins to mix into the atmosphere. General smoky haze is likely for most of the day. Transport winds will remain light westerly to northwesterly through the day and easterly through the night. Evening and nighttime impacts similar to yesterday are likely for the Yosemite and San Joaquin Valley region.
Tuesday September 10 2013
Morning impacts are likely to likely to be about the same for the Yosemite and San Joaquin Valleys. The morning inversion is forecast to be weaker but nighttime easterly flows will keep smoke impacts high for areas west and southwest of the fire. Impacts are predicted to extend further northwest into the Sacramento Valley and foothills during the morning hours as well. Lazy transport winds will be slow to clear smoke but vertical mixing will be fairly decent likely providing some relief in the afternoon hours particularly in the mountains. By late afternoon and into evening smoke will roll back into the Yosemite and San Joaquin Valleys and persist into the following morning. East side communities including Markleeville Minden and Carson City should get a break from heavy smoke for a few days.
Long term Outlook
Wednesday is forecast to be about the same with morning impacts maybe a bit less in the San Joaquin Valley as nighttime downslope winds are predicted to be lighter. Daytime transport winds remain light westerly. Diurnal slope and drainage winds will be the dominant flows in the Sierras and should provide some clearing in the afternoon.