Thursday, September 5, 2013

9/5/2013 Rim Fire Extended Air Quality Report

Rim Fire, Air Quality Resource Advisor Report                           Thursday, September 05, 2013
 Prepared by: Ron Sherron, Leland Tarnay, Sharon Grant, and Ryan Bauer
Key Points:
  • Fire has burned 237,341 acres and is 80% contained.  Minimal growth occurred during the last operational period.
  • Weather conditions were drier yesterday and are expected to get continually warmer and drier through the week. Low pressure moving into Northern California will increase the winds; expect it to become breezy this afternoon with gusts up to 25 MPH out of the south-southeast on the ridges.  Drier conditions and poor RH recoveries will allow fire to move independently through surface fuels. Expect an increase in flame lengths.  Where winds, topography, and sun come into alignment the fire will be able to make short runs in surface fuels with isolated torching.
  • Divisions F,K, and L will continue mop-up activities and monitoring for spot fires. Division Z, a new division, will continue to construct direct fire line east toward Cherry Lake. They will investigate a large glow that was observed in the Cherry Creek drainage last night. On the southeastern portion of the fire, line construction will continue south burning out small sections to improve hand lines and roadways. With the drier and warmer conditions spot fires are becoming more frequent.  Yesterday they lined 5 spot fires in the the eastern portion of the fire, the largest was 0.1 acres. (Figure 1).

Figure 1 Rim fire operations map for 9/5/2013 with MODIS satellite heat detections from 07:30 today (orange dots represent activity within past 12-24 hrs, red dots represent activity within past 6-12 hours) showing location of the  firing and holding operations in the Clavey River drainage (orange), location of late night activity (blue) and area of multiple spot fires threatening direct attack taking place in Branch IV (yellow).

Figure 2 Rim fire infrared perimeter from 9/3/2013 with MODIS satellite heat detection and visible satellite image from 09:00, 9/4/2013 showing location of fire highest fire activity and outline of visible smoke.

Satellite imagery from this morning shows the main body of smoke from the Rim Fire extending north over Pinecrest, Markleeville, Minden, and Carson City, (Figure 2). Air quality monitors in those locations reported impacts in the unhealthy range morning. Smoke again skirts the Lake Tahoe Basin and Reno/Sparks areas with slight impacts in the moderate range (Figure 3).
Smoke settled into Tuolumne City and Sonora overnight due to the slightly stronger inversion, barely reaching as far downslope as Columbia. This is similar to yesterday.

Figure 3 3-hour average fine particulate (PM 2.5) concentration at six (6) monitoring locations downwind of the Rim fire with associated Air Quality Index (AQI) health hazard ranges and adjectives. All data are preliminary and have not undergone quality assurance review.
The air quality monitor at the Drew Meadow ICP was moved to a location farther from vehicle and generator emission sources. It is back up and running with acceptable data as of 15:00 9/3/2013. Smoke impacts continue during the morning hours each day at both base camps. Impacts continue to reach the unhealthy AQI range at Drew Meadow ICP for about 8 hours each day. Tuolumne City has not been in the unhealthy range for the past three days (Figure 5).

Figure 5 3-hour average fine particulate (PM 2.5) concentration in the Drew Meadow and Tuolumne City Incident Base Camps with associated AQI ranges and adjectives. All data are preliminary and have not undergone quality assurance review.

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. 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
For Thurs.
Sept. 5, 2013
Yesterday, Sept. 4, 2013
La Grange
Greeley Hill
El Portal
Tuol. Mdws
Air quality is satisfactory and poses little or no health risk
La Grange
Yosemite Vly. Tuol. Mdws
Yosemite Vly Reno
S. Lk. Tahoe Columbia
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
Tuol. City
Bear Valley



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

Markleeville. Pinecrest
Carson City
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.
Bear Valley

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

Thursday, September 5, 2013
Conditions this morning are about the same as yesterday. A fairly strong inversion once again brought smoke into communities as far downslope of the fire as Sonora and Columbia with about the same intensity. The heaviest morning smoke impacts are in communities to the northeast and in the immediate fire area such as Pinecrest, Bear Valley, Tuolumne City, Markleeville, Carson City, and Minden. Maximum fine particulate (PM 2.5) concentrations in the western portion of the immediate fire area have gradually decreased over the past several days as fuels consume in the older burn area. However, maximum concentrations have not decreased and remain high in downwind areas including Pinecrest, Bear Valley, Markleeville, Minden, and Carson City. This morning’s inversion should break around or a little before noon. All areas should see their best air quality in the afternoon. Daytime transport winds will remain southwesterly, keeping smoke out of the Yosemite and San Joaquin Valleys. Nighttime impacts similar to yesterday are likely for Carson City and Minden (Figure 7), continuing into Friday morning.

Figure 7 2 km BlueSky particle model prediction for 16:00 9/5/2013.
Figure 8 2 km BlueSky particle model prediction for 07:00 9/6/2013.

Friday, September 6, 2013
Smoke impacts continue to follow the pattern of the past two days. There is some hint that early morning impacts could extend further to the southwest and northwest of the fire area than the two previous days, possibly impacting La Grange, Sonora, Columbia, Angels Camp, San Andreas, and potentially even Placerville (figure 8). The morning inversion will be quite strong, probably persisting until noon. Southwest transport winds will continue clean smoke out of the west slopes of the Sierras by sometime in the afternoon. The weather model suggests weaker transport flow east of the Sierra crest, so BlueSky is concentrating smoke in the Carson City and Minden area (Figure 9).

Figure 9 2 km BlueSky particle model prediction for 16:00 9/6/2013.

Saturday, September 8, 2013
Morning smoke impacts are forecast for the Sierra foothills and central valley, under a strong inversion, from Merced northward to Chico (Figure 10). The model’s predictions this far out are likely to change over subsequent runs, but at this point there is agreement on the possibility of more nighttime fire activity and subsequent smoke production associated with a stronger thermal belt, and a strong inversion trapping smoke in the drainages and valley. Afternoon transport winds should remain fairly strong from the west-southwest, clearing valley smoke by early afternoon. Impacts to downwind communities will be similar to those seen all week, although a more westerly component could reduce impacts to Carson City to some degree. The Yosemite region should continue to see fairly good air quality, as models are no longer predicting any northerly component to the transport winds.

Figure 10 2km BlueSky particle model prediction for 07:00 9/7/2013.

Long-range outlook
By Sunday winds are predicted to shift more westerly. This has the potential to send smoke toward Tuolumne Meadows so, we will watch that area closer as the weekend approaches. Estimations of the amount of remaining emissions from burnout and interior burning are currently being refined and may be available later today. A very rough estimate of approximately 20,000 acres of remaining unburned fuels, assuming further growth outside the current perimeter does not occur, still represents the potential for continued emissions from the Rim Fire.                                                 


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