Rim Fire, Air Quality Resource Advisor Report Sunday, September 8, 2013
Prepared by: Ryan Bauer, Leland Tarnay, and Sharon Grant
- The fire size has been updated to 253,332 acres and reamains at 80% contained. About 1,200 acres of growth occurred yesterday, primarily within the current perimeter.
- High temperatures and very dry conditions will continue through today. A strong thermal belt kept humidity low at the higher elevations of the fire overnight, allowing for an earlier start to fire activity, as soon as the inversion breaks this morning. The Haines index is forecasted as 5 again today, indicating greater instability and potential for plume dominated fire behavior and increased spotting. Slope and drainage winds will remain breezy today and ridgetop winds will shift from southwesterly early to westerly and then north-westerly by late afternoon and evening.
- Most of the interior burnout is complete in Divisions J and K, and the change to westerly and north-westerly winds should reduce spotting potential. Efforts continue in Division Z to use direct fireline to contain the fires edge south toward Cherry Lake. Two Wildfire Use Modules continue working the eastern side of the fire to check the fires spread in several timber stringers that run up into the rocks. Firing continues in Branch V along with mop-up along the fires edge. All other Divisions continue mop-up, patrol, and suppression damage repair.
Satellite imagery from this morning shows smoke from the Rim Fire extending west, down the Tuolumne River drainage into the California Central Valley and an area of smoke in the Mono Lake Basin (Figure 2). Air quality monitors west of the fire in Tuolumne City, Groveland, and Columbia measured impacts in the unhealthy range this morning. Data were not available for La Grange, but impacts were reported there by Air Quality personnel as well. Smoke impacts continue to lessen in Markleeville and Minden as winds become westerly to north-westerly; both reached the unhealthy for sensitive groups range this morning.
Air quality monitoring continues at the two incident base camps. Impacts continue to reach the unhealthy AQI range at both locations for a few hours each morning (Figure 4). Data collection has resumed at Drew Meadow after a loss of power.
Table 1 selected air quality monitor data and corresponding AQI rating, meanings, and recommendations with forecast levels for today. Data are preliminary and have not undergone quality assurance review.
Follow the links in the following table to view real-time air quality monitoring data for each site.
24-hour Avg PM2.5
3-hour Max PM2.5
Level of Health Concern
Actions to Protect Yourself
Sept. 8, 2013
Yesterday, Sept. 7, 2013
Yosemite Vly Tuol. Mdws
Air quality is satisfactory and poses little or no health risk
S. Lk. Tahoe Columbia Carson City
Air quality is acceptable for most. There may be moderate health concern for a small number of sensitive people.
Unusually sensitive people should consider reducing prolonged or heavy outdoor exertion.
S. Lk. Tahoe
La Grange Markleeville
Unhealthy for Sensitive Groups
Members of sensitive groups may experience health effects. The general public is not likely to be affected.
People with heart or lung disease, children and older adults should reduce prolonged or heavy outdoor exertion. Everyone else should limit prolonged or heavy exertion.
Yosemite Vly. Tuol. Mdws
Drew Mdw ICP*
Everyone may begin to experience more serious health effects.
The following groups should avoid all physical outdoor activity: People with heart or lung disease, children and older adults. Everyone else should avoid prolonged or heavy exertion.
Air Quality Index (AQI) ratings are derived based on the recommendations found in Wildfire Smoke: A Guide for Public Health Officials.
Sunday, September 8, 2013
More fire activity yesterday and into the night, coupled with a stronger inversion caused smoke to drain down the Clavey and Tuolumne River drainages, into the Lake Don Pedro basin and further into the central valley than previous mornings. Morning air quality impacts were heaviest in Tuolumne City, Pinecrest, Bear Valley, Markleeville, and Columbia. Le Grange and Minden both experienced impacts this morning as well. The inversion should break by noon in all areas. Transport winds will shift through the day from southwesterly early, to west-northwesterly by late afternoon, likely bringing heavier smoke into the Tuolumne Meadows area, Yosemite Valley, El Portal, and the San Joaquin Valley later in the day. Nighttime impacts similar to yesterday are likely for Minden, and may increase further south in Bridgeport and Lee Vining.
Monday, September 9, 2013
Significant morning impacts are likely to extend south into the Yosemite and San Joaquin Valleys possibly as far as Fresno (Figure 7). Tuolumne City, Sonora, Columbia, Groveland, La Grange, Yosemite Valley, Tuolumne Meadows, and El Portal will see impacts increase over previous days. The morning inversion is still forecast to be quite strong, and likely to persist until around noon. Transport winds will be weak westerly and possibly even northwesterly late in the day. Any relief should come in the afternoon, but by evening smoke will roll back into the Yosemite and San Joaquin Valleys and persist into the following morning (Figure 8). East side communities, including Markleeville, Minden, and Carson City should get a break from heavy smoke for a few days.
Long Term Forecast: