AQI Forecasting in the Puget Sound

1
AQI Forecasting in the Puget Sound
2
Our Role

• We operate 11 air monitoring sites that provide
  year round real-time data. (Pm10, pm2.5, Nephs)
• We provide AQI reporting/forecasting services
  Seattle and Tacoma MSAs
• We are a member of the Washington state network

3
Is this worth doing?

• Returning products to the taxpayers.
• Investments in Monitoring
• Investments in MM5 project
• An Informed public
• People like to make their own decisions
• Increase awareness of air quality issues
• Support operational programs
• Burn bans
• Smog watch

4
Program Goals

• Provide 48 hour notice of expected air quality
  conditions.
• Provide 72-96 hour notice for internal planning.
• Predict predominate AQI conditions.
• Improve tools and products.
• Establish a lasting year round program
• Disseminate via AIRNOW and Local Web site, TV
  Weather Teams

5
Resources

• Existing Air monitoring network
• Regional modeling effort and tools
• Availability of meteorological tools via internet
• Staff resources
• E-Government approach for dissemination
• Senior Leadership support

6
Factors that influence PM forecasts

• Fine Particulate properties
• Help in making area forecast
• Local knowledge of communities
• Available Meteorological/Monitoring Products
• Improvements in synoptic and Mesoscale tools
• Recent performance of models
• Air Monitoring network
• Behavioral changes
• Perceptions of heating cost
• Burning in early fall.
• Summer fuel strategies

7
What pollutants are important?

• Diverse air shed
• Particulate is the primary driver of AQI
• Summer ozone
• Generally only an issue 5-7 days over the summer
• PM still persistent driver of AQI
• Other criteria pollutants no factor

8
Puget Sound Air Shed
9
Puget Sound Ozone 1996-2000
10
Summer 2001

• What Ozone?
• Very cool summer! 3rd year in a row.
• Provided Air Quality forecasts for PNW2001 air
  operations

11
Wood Smoke Burn Ban 2001

• We can restrict the use of wood burning
• PM 10 conditions reach 60µg/m3 (24hr avg.)
• Stagnant conditions are expected to last 48 hours
  or more
• Wood smoke is believed to be a major contributing
  factor

12
Wood smoke Burn Ban 2001

• Weather conditions over area
• High Pressure ridge (SFC-500mb)
• Moderate to Strong inversion
• Offshore low level wind flow
• Light wind speeds at surface
• Cool/Cold (

13
Wood smoke Burn Ban 2001

• Synoptic Models gave indication of pattern
• 120hrs out.
• Uncertainty of performance impacted internal
  notification
• Time duration of event
• Mesoscale models added confidence

14
Implementation

• AQI forecasts called for Moderate and declining
  trend
• 06 Nov
• Internal planning
• NWS Coordination (Air Stagnation Watch)
• Forecasted Unhealthy for Sensitive Groups.
• Issued on the 7th of Nov
• Worked with King 5 TV
• Could not implement Burn Bun
• High confidence in Models
• Issued Burn Ban
• 10 AM 08 Nov made final decisions
• 2 PM 08 Nov to 6 PM 12 Nov

15
Puget Sound Air Shed
16
Monitoring Network Corrections
17
Industrial- Central Seattle
Called Burn Ban
18
Residential-North
19
Commercial/Residential-South
20
Residential- Tacoma
Burn Ban
21
Residential Tacoma
22
Conclusions

• Feedback from users indicated we met our
  objectives
• Local knowledge is critical to forecasts.
• Down to neighborhood level.
• Monitoring equipment performance/bias
• Forecaster experience
• Daily review of MRF products and performance
• Important to being proactive in planning

23
NEXT STEPS

• Develop a better verification program
• Predominate condition versus peak value
• AQI Categories versus Concentration
• Some customers use forecast for notification of
  highly sensitive groups
• Prefer to join in a larger effort
• Expand the program
• Consider adding more forecast points
• Refine monitoring network to better support the
  forecast program

24
Air Quality Index
25
Variability in the air shed
26
Thank You!

• Like a stock broker..
• We are not troubled by LONG periods of
  uninterrupted success.