Yosemite National Park
Prepared: 9/19/16
Prepared by: Jim McNitt, Air Resource Specialist
Overview:
The Lakes Fire is burning in the Chilnualna Lakes area, between Turner Meadow
and Buena Vista Peak at about 8,000 feet in a designated wilderness area in
Mariposa County. It is a lightning-caused fire that is being monitored and
managed for resource and wildlife benefit. Managing fires that are started by
lightning reduces the risk of high intensity fires and benefits the ecosystem. The
size is estimated to be approximately 587 acres based on ground reconnaissance
completed on 9/17/16. A prescribed burn was conducted at Ahwahnee Meadow with
ignitions on 9/12/16 and 9/13/16 for approximately 62 acres. Burn down and mop
up was completed on 9/15/16. Smoke from other wildfires will continue to elevate PM2.5 levels in the park.
Smoke
Synopsis: A temperature inversion will trap smoke in Yosemite Valley
overnight but the temperature inversion will break down by noon. Overnight smoke settled down the Chilnualna
drainage to Wawona through the early morning today and several hourly PM2.5
readings at Wawona were greater than 35 µg/m3 this morning. Afternoon upslope flow and overnight and
early morning downslope flow will continue through Tuesday.
Air
Quality Outlook: High pressure
over the area will cause fair to poor dispersion conditions today and tomorrow.
Dispersion
conditions will improve on Wednesday as a cold front approaches from the west
and winds will be gusty Wednesday night. The cold front will pass through the
area on Thursday. Expect gusty winds and good vertical mixing of smoke as the
front moves through on Thursday. Dispersion conditions on Friday will be fair
but dispersion conditions will deteriorate throughout the weekend and will be
poor by Sunday.
Location
|
Yesterday
9/18/16 Observed* |
Today
9/19/16 Forecasted |
Tomorrow
9/20/16 Forecasted |
Details for avoiding smoke during
the worst hours of the day
|
Yosemite Valley
|
Moderate
|
Moderate
|
Moderate
|
Campfire smoke will be trapped under a surface inversion Monday night/Tuesday
morning. The highest hourly readings will be between 10 PM and 6 AM.
|
El Portal
|
Good
|
Good
|
Good
|
|
Wawona
|
Moderate
|
Moderate
|
Moderate
|
People with heart or lung disease, children and older adults
should reduce prolonged or heavy outdoor exertion in the morning. The highest
hourly readings will be between 5 AM and noon.
|
Disclaimer:
Air quality predictions reflect only fine particulate matter (PM2.5). Sensitive individuals including
people with asthma or heart disease, infants, children, pregnant women and
older adults should take precautions to avoid exposure to smoke. If you
experience health effects from smoke, contact your
health professional. *The
Air Quality Index (AQI) values used to create the following table are 24-hr
averages (midnight-midnight local time). Locations listed in the above table can
experience periods of poorer air quality than the24-hr average.
|
||||
24 hr AQI Category
(PM2.5 µg/m3) |
Potential Health Impacts
|
Actions to Protect Yourself
|
Good
(0-12)
|
Little or
no health risk
|
None
|
Moderate
(13-35)
|
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.
|
Unhealthy
for Sensitive Groups – USG (36-55)
|
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.
|
Unhealthy
(56-150)
|
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.
|
Very Unhealthy
(151-250)
|
Triggers a health alert, 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.
|
Hazardous (>250)
|
The entire population is even more
likely to be affected by serious health effects.
|
The following groups should remain
indoors and keep activity levels low: People with heart or lung disease;
children and older adults. Everyone else should avoid prolonged or heavy
exertion
|
Learn more at:
Air Monitor
Data http://www.wildlandfiresmoke.net/monitoring/
California
Smoke Blog http://www.californiasmokeinfo.blogspot.com/
Air
Districts http://www.arb.ca.gov/capcoa/roster.htm
AirNow (AQI
forecasts and nowcasts) https://www.airnow.gov/
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