INTERPRETATION

BENEFIT AND LIMITATION

GLOSSARY

Local 3-Month Temperature Outlook - Probability of Exceedance Table

The Local Three-Month Temperature Outlook (L3MTO) Probability of Exceedance (POE) Table shows the expected chance, in percent, for the average three-month temperature to exceed (be higher than) a specified temperature in degrees Fahrenheit.

The Table consists of 14 columns and 23 rows. Outlook data for thirteen 3 -month consecutive periods are shown in columns 2 though 14 with the first row providing the three-month period titles. The outlook data show the following information in rows 2 through 23:

• Row 2: R is the correlation coefficient (unit-less value between -1 and 1) that indicates the strength of the relationship between the station data and the corresponding Climate Division (forecast region) data, used in the National three-Month Outlook. The higher the value of "R", the stronger the correlation or relationship.
• Rows 3 though 21: show the expected chances (labeled in the first column) for the average three-month temperature to exceed (be higher than) the specified temperatures (in degrees Fahrenheit) in columns 2 though 14 for the three-month outlook periods.
• Row 22: the Mean is the forecast expected value (in degrees Fahrenheit), or expected center of the average three-month temperature distribution
• Row 23: StDev is the Outlook Standard Deviation (in degrees Fahrenheit), or a measure of expected spread of the average three-month temperature distribution about the Mean.

The Table shading indicates whether the outlook average three-month temperature values are above or below those of the 1981-2010 reference period, and to what degree. A legend for the shaded values (in degrees Fahrenheit) is located at the bottom of the page.

L3MTO POE Table Outlook Interpretation Example for July through September 2006:

The interpretation example will be given the value 62.6°F indicated by the blue border: There is a 60% chance that the average three-month temperature in July-August-September 2006 will be higher than 62.6°F. This temperature is between 0.5°F and 1.0°F warmer than the 60% POE temperature in 1981-2010