Rim Fire, Air Quality Resource Advisor Report Monday, September 9, 2013
Prepared by: Ryan Bauer, Leland Tarnay, and Sharon Grant
- The fire size remains 253,332 acres and is 80% contained. About 3,000 acres of growth occurred yesterday, primarily within the current perimeter.
- High temperatures and very dry conditions will continue through today. The Haines index is forecast to be 5 again today, indicating high instability and potential for plume dominated fire behavior and increased spotting. Slope and drainage winds will remain breezy today and ridgetop winds will be westerly to north-westerly during the day. Stronger easterly winds will return tonight.
- 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. Direct fireline was completed in Division Z to Cherry Lake; crews will continue holding and containing spot fires there today. 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. Most of the remaining burnout in Division P was accomplished as a result of yesteday’s fire activity, and mop-up along the fires edge continues. All other Divisions continue mop-up, patrol, and suppression damage repair.
Satellite imagery from this morning shows smoke from the Rim Fire extending south into the San Joaquin Valley and west to meet the smoke from the Morgan Fire (Figure 2). Air quality monitors southwest of the fire in Groveland, Greeley Hill, La Grange and El Portal measured impacts in the moderate to unhealthy for sensitive groups range this morning (Figure 3). Smoke impacts continue to lessen in Markleeville and Minden as winds become westerly to north-westerly; both were in the good range this morning.
Air quality monitoring continues at the two incident base camps. Smoke impacts reached the very unhealthy range in Tuolumne City yesterday, but today there is a break from the smoke as a result of the change in transport winds. The same wind change increased impacts for the Drew Meadows Camp (Figure 4).
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. 9, 2013
Yesterday, Sept. 8, 2013
Air quality is satisfactory and poses little or no health risk
S. Lk. Tahoe
S. Lk. Tahoe 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.
Markleeville Minden Yosemite Vly*
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.
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.
Greeley Hill Columbia
Drew Mdw ICP
Triggers a health alert, meaning everyone may experience more serious health effects
Everyone should avoid any outdoor exertion; people with respiratory or heart disease, the elderly and children should remain indoors.
Air Quality Index (AQI) ratings are derived based on the recommendations found in Wildfire Smoke: A Guide for Public Health Officials.
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 (Figure 6). 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.
Wednesday, September 11, 2013
Not much is predicted to change between Tuesday and Wednesday. Nighttime downslope winds will be weaker on Tuesday so morning smoke impacts in the foothills and San Joaquin Valley may be slightly less intense Wednesday (Figure 9). 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 (Figure 10). The impacts shown in the Lake Tahoe Basin are associated with smoke from the American Fire that has not materialized over the past several days. Smoke impacts are likely to persist in areas south of the fire until the weather pattern changes, and depend largely on the amount of fire activity seen each day as the Rim fire nears full containment.