Lagged relationships between North American snow mass and atmospheric teleconnection indices

Relationships between North American winter (January, February, March or JFM) snow mass, or snow water equivalent (SWE), between 1980 and 1997, and four teleconnection indices are explored at different spatial and temporal scales, with teleconnection indices leading SWE by one to two seasons. Summer (July, August, September, or JAS) and fall (October, November, December, or OND) Pacific North American pattern (PNA), North Atlantic Oscillation (NAO), El-Nino Southern Oscillation (ENSO), and the Pacific Decadal Oscillation (PDO) are included in this analysis. Principal components analysis of the SWE data set results in four components, explaining over 56% of the variance in the SWE signal which have significant relationships to ENSO, PDO, and NAO. Strong spatial components associated with these relationships emerge, with the first component (NAO, ENSO) located in the northcentral to northwestern regions of the United States and the southcentral to southwestern regions of Canada. A third component (PDO) stretches from the midwest to the east coast of the United States, New England, and the Atlantic Provinces. Ranked correlation analyses using the SWE data set, and additional analyses of station observations in order to extend the time domain, corroborate and elucidate the PCA results. Examinations of these relationships at different spatial scales, and over varying time domains, indicate that there may be some scale-dependant predictive ability for North American snow mass. Copyright (c) 2006 Royal Meteorological Society