Project Description

Forecasting is a difficult business, and even a meteorologist whose been forecasting all his/her life, will once in a while totally blow a forecast. So don't get frustrated.

Forecasting and Data Collection:
By forecasting on a regular basis, you'll experience the difficulty involved in making a forecast under changing weather conditions. You'll be able to investigate the accuracy of your forecasts through comparison with actual observations.

Part I: Choose a City
The first step is to choose a city to forecast for which to forecast. Be certain you are able to access current weather data for this city to compare with your forecasts. Check the list of station cities. Certain cities are not part of our project. Check with your teacher. Describe the current weather in your city.

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Part II: Make a Forecast
Make a forecast of temperature, cloud cover and precipitation for each day for the city you have chosen for a particular time of day. An example forecast has been given below.

If your class meets at 10AM on Monday, then forecast the temperature and precipitation for 10AM Tuesday, 10AM Wednesday and 10AM Thursday. When forecasting precipitation, indicate whether or not precipitation will occur and if it does, indicate what type.

Here are some helpful hints for making your forecast:
- Look at the current weather conditions. Look for any significant weather features that could influence the weather in your area. (low pressure centers, warm fronts, cold fronts).

- Access an image from 12 hours ago and see how quickly these features have moved during this time period. Using the trends method, estimate when these features might enter the forecast area.

- Look at the temperatures and weather conditions upstream (in the direction from which the wind is blowing) of the forecast area. This weather is heading your way.

Record the values for temperature, dew point temperature, winds, cloud cover and what type of precipitation was occurring (if any).

Type up your forecast and include images of the maps you used to make the forecast. You must include at least two maps. Be sure to include the maps and not just a link. Often links are to current weather (info at one specific time) and the information changes throughout the day. In addition write a paragraph summarizing the current weather conditions, including any information about fronts or cyclones (lows) that may be influencing the weather experienced by your city.

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Part III: Calculating the error of your forecasts - this is done at the end of several days of forecasting:

Compare your forecasted values for each day with the actual observations to determine how accurate your forecasts were. For each temperature value, determine the difference between the forecasted value and observed value.

Your forecasted temperature: 56
Observed temperature: 62
Error: 6 degrees

Accuracy of Temperature Forecasts:
Calculate the average error in your temperature forecasts by summing up all the differences and dividing by the total number of temperature forecasts made.

Avg Error = (sum of degrees error) / (total days forecasted)

Accuracy of Precipitation Forecasts:
For analyzing the precipitation forecasts, how many days did you make a correct forecast? Compute your percentage of accuracy by dividing the number of correct precipitation forecasts by the total number of forecasts made.

% accuracy = { (number of correct forecasts) / (total forecasts) } *100%

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Part IV:  Analyzing the Data - done at the end of all forecasts:

Discuss each point below in your analysis.

Comparing Day 1 Forecast with Day 4 Forecast of your last forecast:

- How did the accuracy of your temperature forecast compare for day 1 and day 4?
- How did the accuracy of your precipitation forecasts compare for day 1 and day 4?
- Use the calculated numbers to back up your results.
 

Comparing Day 2 Forecasts with Day 5:

- How did the accuracy of your forecast for day 2 compare with your forecast for day 5?
- How did the accuracy of your precipitation forecasts compare for day 2 with your forecast for day 5?
- Use the calculated numbers to back up your results.

Comparing Day 3 Forecast with Day 6 of your last forecast

- How did the accuracy of your 3rd forecast compare with your forecast for day 6?

- How did the accuracy of your precipitation forecasts compare for day 3 with your forecast for day 6?
- Use the calculated numbers to back up your results.

Comparing 4th, 5th & 6th Forecasts with 1st, 2nd and 3rd Forecasts

- How did the accuracy of your 4th - 6th forecasts compare with the accuracy of your 1st - 3rd forecasts?
- Use the calculated numbers to back up your results.

Why Were There Errors in Predicting Weather Conditions?:
During what types of weather conditions were your forecasts most accurate? During which weather conditions did your values have the greatest margins of error? When answering these questions, consult the observations you took for each day that was forecasted. Consider factors like:

- Cloud Cover
- Winds
- Dew point temperatures
- High or  low pressure centers
- Fronts
- Or other weather features that may have played a role in your missed forecasts.

Final Analysis:
Here are some final questions to consider:
- Did you show improved accuracy in your forecasts after completing several forecasts?
- What issues did you learn about weather forecasting that you did not know before hand?