# Presentation: 167364

## Daily Forecast Operations

- Nine steps to produce an accurate air quality forecast – a suggested method.
- Review yesterday’s forecast
- Review latest air quality data
- Review synoptic weather
- Run forecast tools
- Develop conceptual forecast
- Produce final forecast
- Document forecast
- Distribute forecast
- Monitor air quality and meteorology

## Step 1:  Review Yesterday’s Forecast

- Did the air quality forecast for yesterday verify?  If the forecast missed by more than 20 to 30 ppb, a retrospective study is recommended
- Did it verify for the right reasons?  For example, forecast for low ozone because of predicted rain, but low ozone occurred with no rain.
- Did all monitors report data yesterday?
- Are there any bad data points?
- If the forecast didn’t verify, does that affect the forecast you plan to issue today?

## Step 2:  Review Latest Air Quality Data

- Are all sites reporting data today?
- How does yesterday’s air quality compare with today’s
- Morning precursor concentrations can help you predict peak air quality – but be careful!

- Look at multiple pollutants:  ozone, NOx, NO, NO2, CO
- Consider the meteorology when reviewing the morning air quality.
- Realize that morning ozone is often lower on days with high ozone compared to days with low ozone

## Step 3:  Review Synoptic Weather

- What is the general synoptic pattern?
- Ridges and troughs
- Upper-level warming and cooling
- Surface and aloft winds
- Is the large-scale pattern changing?
- Are these changes going to influence local weather and air quality?
- If weather forecasts are predicting conditions conducive for good air quality, consider skipping to Step 6, Producing the Final Forecast

- 12Z July 30

- 12Z July 31

- 12Z Aug 1

## Step 4:  Run Forecast Tools

- Gather and review forecast and observational data needed to run the forecast tool(s).
- Run the tool(s) .
- Tweak input values to estimate the impact of uncertainties in the weather forecasts.
- Save inputs and outputs for future verification.

## Step 4:  Run Forecast Tools – Example

- Input form for regression forecasting tool for Nashville, Tennessee.

**Notes:**
Bring  real  model

## Step 5: Develop Conceptual Forecast

- Use your conceptual understanding to fill in the following air quality forecast worksheet.
- Worksheet is designed to capture important processes that influence air quality.

## Step 5: Develop Conceptual Forecast

- Example forecast worksheet for ozone

## Step 6:  Produce Final Forecast

- Review output from forecast tools and conceptual forecast.
- Do the forecasts from different tools agree?
- If so, either average forecast results or use the high or low values, depending on your program objectives.
- If not, check inputs for each tool.

|  | Conceptual | Tool | Final |
| --- | --- | --- | --- |
| Today | 80 | 70 | 40 |
| Tomorrow | 100 | 103 | 101 |

## Step 7:  Document Forecast

- Document forecast rationale
- What happened yesterday?
- What’s expected today and tomorrow and why?

## Step 8:  Distribute Forecast

- Ensure distribution of forecast before the deadline by planning daily timeline.
- Distribution
- Internal (technical details) and
- Public (generalized and health-oriented)
- E-mail
- Fax
- Internet
- Phone
- Pager

## Step 9:  Monitor Air Quality and Meteorology

- Monitor the air quality and meteorology throughout the day for unexpected changes.
- Update forecast if meteorology or air quality is different than expected.
- Ensure that incoming data are  reasonable given the meteorological/air quality conditions.