INTERPRETATION

BENEFIT AND LIMITATION

GLOSSARY

Local 3-Month Temperature Outlook (L3MTO) Pie Chart

The Local Three-Month Temperature Outlook (L3MTO) Pie Chart shows the expected chance for the average three-month temperature to occur in one of three temperature categories: Above, Near or Below Normal. The categories are based on observations from the present climatological reference period of 1971 through 2000. During this 30-year period, temperatures were in the Below Normal category 1/3 (33.3%) of the time, in the Near Normal category 1/3 (33.3%) of the time, and in the Above Normal category 1/3 (33.3%) of the time. In other words, during 1971-2000, there was an Equal Chance (EC) for the average three-month temperature to fall in any one of the three categories. The L3MTO reflects a change in these odds at a particular station. These local station outlooks are based on the National Three-Month Temperature Outlook.

The presentation format for L3MTO is a pie chart with three slices representing the three forecast categories:

• The red slice represents the forecasted chance for the actual -month temperature to be in the Above Normal category (i.e. higher than the 1971-2000 temperature used to define this category's limit)
• The blue slice represents the forecasted chance for the actual three-month temperature to be in the Below Normal category (i.e. lower than the 1971-2000 temperature used to define this category's limit)
• The gray slice represents the forecast chance for the actual three-month temperature to be in the Near Normal category (i.e. between the 1971-2000 temperatures used to define the Near Normal category)

The legend, located to the right of the pie chart, has three colored boxes with colors that respectively correspond to a slice of the pie chart. Each legend box indicates the actual expected chance for that outlook category and its associated 1971-2000 temperature value used to define this category.