Analogous Season

An Analogous Season is the period from the climate division’s history whose precipitation patterns most resemble the period of interest. Only the periods whose dates correspond with the period of interest’s dates are considered. In other words, if the period of interest is the 30-day period ending March 21st, all 30-day periods ending March 21st are compared with the period of interest and a "winner" is determined based on the analogous season score. The calculation of the analogous season score is outlined below.

Notation:

Score Components: The Analogous Season Score is divided into 3 components.

Analogous Season Score: The score is calculated by summing up components c1, c2 and c3. The score for season i when compared to the current season n :

scorei = 10- (c1 + c2 + c3)
(5)

Analogous Season Algorithm: The steps to determine the most similar season:

Interpretation of Scores




10.00 Perfect match: Precipitation patterns are identical to period of interest
9.50-9.99 Very strong match
9.00-9.49 Significant match
8.50-8.99 Moderate match
8.00 or less Weak match: period of interest is unique in history