9/11/2013 Rim Fire Air Quality Report

Air Quality Report                                               Wednesday, September 11, 2013

Rim Fire, Stanislaus National Forest

As air quality impacts from the Rim fire continue to diminish over the next several days, this report and the extended report will be replaced by a less formal informational update, posted as needed in the event that a significant impact is forecast.

Yesterday, September 10, 2013

The Rim Fire burned approximately 700 acres, about 400 ac within the containment lines. It is currently 255,146 acres. Afternoon thunderstorm activity along the Sierra crest helped to stir up the atmosphere, providing some good smoke mixing that reduced air quality impacts throughout the region yesterday and into this morning. All areas saw improvement in their air quality from the previous days.

Wednesday, September 11, 2013

Light downslope winds overnight carried less smoke than on recent mornings down the Clavey and Tuolumne River Drainages. Smoke impacts in the communities usually affected by morning inversions were lighter today, with Pinecrest, Columbia, Groveland, Greeley Hill, La Grange, El Portal, and Mariposa all in the good to moderate AQI ranges. Light smoke will linger in the Yosemite Valley and foothill communities for most of the day. Transport winds will remain light through the day. Diurnal upslope/upcanyon flows will be the dominant winds. A slightly better chance of thunderstorms over the Sierras today could again help smoke mix into the upper atmosphere, improving air quality conditions on the surface. Eastly winds will remain fairly weak tonight bringing nighttime and early morning impacts similar to this morning for the Yosemite and San Joaquin Valley foothill region.

Thursday, September 12, 2013

Not much changes from today as we go into Thursday. Similar morning impacts can be expected in areas where the inversion will cause smoke to settle. Afternoon thunderstorm chances are lower than for Wednesday, but still possible. Transport winds may begin to turn a little more northerly late in the day as high pressure begins to rebound over southern and central California. Nighttime easterlies will begin to strengthen over the next couple days, but impacts will likely remain about the same for the Yosemite region and San Joaquin Valley foothills.

Long term Outlook

Smoke dispersion conditions will begin to worsen going into the weekend as a high pressure ridge develops to the west. Temperatures increase over the weekend and winds may again become northwesterly, with stronger easterly winds developing in the nighttime hours. Air quality impacts may begin to lessen some as the Rim fire nears full containment, currently expected on September 20th.

Follow the links in the following table to view real-time air quality monitoring data for each site.

Site	24-hour Avg PM2.5 (µg/m3)	3-hour Max PM2.5 (μg/mᵌ)	Level of Health Concern	Meaning	Actions to Protect Yourself	Forecast For Wed. Sept 11, 2013
	Yesterday, Sept. 10
Reno Bear Valley Markleeville S. Lk. Tahoe Carson City Minden	3 6 5 4 6 10	9-10:00 13-20:00 14-23:00 14-11:00 10-09:00 29-12:00	Good	Air quality is satisfactory and poses little or no health risk	None	Reno Bear Valley Markleeville S. Lk. Tahoe Carson City Minden
Mariposa Greeley Hill La Grange El Portal Columbia Pinecrest Yosemite Vly Groveland   Tuol. Mdws	12 13 14 21 21 27 25 25 30	51-11:00 30-11:00 29-09:00 36-03:00 63-11:00 86-12:00 52-23:00 61-11:00 82-00:00	Moderate	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.	Mariposa Columbia La Grange El Portal Yosemite Vly Pinecrest Greeley Hill Tuol. Mdws
Tuol. City	42	107-07:00	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.	Tuol. City Groveland .
Drew Mdw ICP	100	252-10:00	Unhealthy	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.	Drew Mdw ICP

Air Quality Index (AQI) ratings are derived based on the recommendations found in Wildfire Smoke: A Guide for Public Health Officials.