Sub‐regional seasonal precipitation linkages to SOI and PDO in the Southwest United States

Abstract

This paper highlights the relationship between precipitation variability at the sub‐regional level in the Southwest United States and the SOI and PDO climate teleconnection indices during the period 1950–2000. Statistical correlations at α = 0.05 and 0.01 levels are calculated for fall, winter, and spring precipitation in the Southwest, and contemporaneous and antecedent seasonal SOI and PDO index values. A strong SOI‐winter precipitation signal is seen to progress across Arizona and New Mexico from southwest to northeast over a three‐season lagged period. The PDO also exhibits a strong relationship with winter and spring precipitation in New Mexico; however, the PDO is not well correlated with precipitation in Arizona. The results underscore the non‐uniform spatio‐temporal relationships of the SOI and PDO indices as they relate to the precipitation regime of the Southwest, and provide a framework for future diagnostic analyses of these relationships. Copyright © 2003 Royal Meteorological Society.