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

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 corrections at alpha = 0.05 and 0.01 leves are calculated for fall. winter, and spring precipitation in the Southwest, and contemporaneous and antecedent sesonal SOI and PDO index values. A strong SOI-Winter precipitation signal is seen to the progress across Arizona and New Mexico from southwest to northwest 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. (C) 2002 Royal Meteorological Society