Monday, September 2, 2013

9/2/2013 Rim Fire Extended Air Quality Report

Rim Fire, Air Quality Resource Advisor Report                            Labor Day, September 2, 2013
 Prepared by: Ron Sherron, Leland Tarnay, Sharon Grant, and Ryan Bauer
Key Points:
·         Fire has burned 231,088 acres.  8,310 acres of growth during the last operational period.
  • Increased moisture in the area and currently, light precipitation on the fire (Figure 3) has helped to calm the fire activity.  Steady light winds overnight kept smoke from settling in some areas like has been seen over the past several days.  Upslope/upcanyon flows are expected today with breezy South-Southwestern winds on the ridges today and Tuesday.  Gradually warmer and drier conditions are expecdted throughout the week.
  • Crews are concentrating efforts on lining a spot fire that occurred on the southern portion of the fire in Division S (Figure 1).  Plans to burnout the eastern portion of the fire have been postponed as higher moisture and help from existing fuel treatments and fire history allow crews to start direct attack today, beginning at Harden Lake and making their way south. The burnout on the north end of the fire continues (Figure 1).
  • Light flashly fuels will dry out quickly as temperatures increase.  Chances still exist for the fire to make short runs in surface fuels, allowing for some tree torching and spotting.  Spotting has been observed up to 4 miles away on this fire.
  • Incident Management Teams will switch out Tuesday, and demobiliztion of someresources has begun.
Figure 1 Rim fire infrared perimeter and hotspots with fire history data in blue showing location of the spot fire in Division S, and burnout in Division F.

Figure 3 Rim fire infrared perimeter from 01:55 9/2/2013 with weather radar from 08:30, 9/2/2013 showing a band of moisture that brought light showers to portions of the fire.

Air quality monitors in the area north of the fire are depicting impacts associated with an increase in fire activity late yesterday. Smoke in Pinecrest has remained in the unhealthy to very unhealthy range since about 22:00 last night. Further downwind, air quality in Bear Valley and South Lake Tahoe reached the unhealthy range for a few hours early this morning as a result of the same fire activity. Impacts remain evident in the monitoring data from early morning thru the early afternoon hours for most of the communities within the immediate fire area (Figure 4). Impacts during this period have been significant as far west as Columbia and La Grange.
Figure 4 3-hour average fine particulate (PM 2.5) concentration at five (5) monitoring locations adjacent to the Rim fire with associated Air Quality Index (AQI) health hazard ranges and adjectives.

Smoke impacts in the Yosemite region peaked yesterday around noon and have steadily improved since then (Figure 5). Southwest winds expected to remain dominant over the next several days should keep air quality in the Yosemite region in the good range through the period.

Figure 5 3-hour average fine particulate (PM 2.5) concentration in the Yosemite region with associated AQI ranges and adjectives.

Figure 6 air quality monitoring sites in the Rim Fire area with Rim fire infrared perimeter from 20:18, 9/1/2013.

Table 1 selected air quality monitor data and corresponding AQI rating, meanings, and recommendations with forecast levels for today.

24-hour Average PM2.5
3-hour Max PM2.5
Level of Health Concern


Actions to Protect Yourself
For Mon.
Sept. 2, 2013
La Grange
Air quality is satisfactory and poses little or no health risk
La Grange

S. Lk. Tahoe Greeley Hill

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.
Yosemite Vly.
Tuol. City
El Portal

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.
S. Lk. Tahoe
Tuol. Mdws
Bear Valley
Tuol. Mdws* Markleeville Yosemite Vly.*

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.
Bear Valley
Tuol. City



Very Unhealthy
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.

Drew Mdw ICP
Everyone may begin to experience more serious health effects.
People with heart or lung disease, children and older adults should avoid all physical outdoor activity. 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.
*-Data did not meet quality control standards. Instruments tend to overestimate heavy smoke concentrations under low flow.

Labor Day, September 2, 2013
Smoke again had the heaviest impacts to communities in the immediate fire area such as Groveland, Tuolumne City, Pinecrest, Bear Valley, and Greeley Hill in the morning hours. Due to a late increase in fire activity last night Pinecrest , Bear Valley, South Lake Tahoe, and Markleeville saw higher smoke impacts than those seen on previous days. Last night’s fire activity doesn’t appear to have crossed the Sierra crest, so impacts this morning should be mild in Reno, Carson City, and Minden; although smoke may return in the afternoon it looks like impacts will be fairly light. Daytime transport winds will remain southwesterly, reducing impacts to the Yosemite Valley, El Portal, and the San Joaquin Valley.

Tuesday, September 3, 2013
Smoke impacts will be similar to today. Morning impacts will be highest north of the fire area, with smoke likely in Pinecrest, Bear Valley, Tuolumne City, Markleeville, and South Lake Tahoe. Southwest winds will continue to clean out smoke basins by early afternoon and should keep areas south and southwest of the fire mostly smoke free. Carson City and Gardnerville/Minden may see moderate impacts in the late afternoon if downslope winds develop east of the Sierra crest (figure 8).
Figure 7 2 km BlueSky particle model prediction for 08:00 9/3/2013.
Figure 8 2 km BlueSky particle model prediction for 16:00 9/3/2013.

Wednesday, September 4, 2013
Smoke impacts continue to follow the pattern of the past two days. There is some hint that early morning impacts could extend further south and west of the fire area than the two previous days, possibly impacting La Grange, Sonora, and Columbia (figure 9). Southwest winds will continue their dominance, cleaning smoke out of the west slopes of the Sierras by early afternoon. The BlueSky model suggests a slightly more northerly path for the plume in the afternoon (Figure 10). We will continue to watch the models predictions on that for the potential for greater impacts to Reno or even Virginia City.
Figure 9 2 km BlueSky particle model prediction for 07:00 9/4/2013.

Figure 10 2 km BlueSky particle model prediction for 16:00 9/3/2013.
Long-range outlook
Southwest transport winds will dominate for the next several days. This should keep air quality in the Yosemite Valley and areas south of the fire in the good to moderate range. Areas north and northeast of the fire, including the Lake Tahoe Basin, and Washoe and Carson valleys will see higher impacts. Communities within the immediate fire area will continue to see intense morning smoke.

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