A diagnostic comparison of the 1980 and 1988 US summer heat wave- droughts

Abstract

Observational analyses are performed to examine the roles of remote and local forcing in the evolutions of the extreme US summer heat wave-drought cases of 1980 and 1988. At early stages, both events are associated with anomalous stationary wave patterns. Wave activity flux analyses suggest that in the 1980 case anomalous wave activity propagates southeastward from an apparent source region to the south of the Aleutians. The flux pattern is more complex in the 1988 case but suggests two possible source regions, one over the central North Pacific to the north of the Hawaiian Islands and a second located over the far western Pacific. Overall, the results indicate the importance of both dynamical forcing from remote sources and anomalous local boundary conditions in accounting for the two extreme heat wave-drought events. -from Authors