Workshop assesses 1997”1998 El Niño from Pacific climate perspectives



As the 1997–1998 El Niño was drawing towards its apparent end, researchers from various disciplines at the 15th Pacific Climate (PACLIM) Workshop recognized several significant features of this El Niño. First, a confident and credible long-term climate forecast was issued well in advance of the event, and, more importantly, it was taken seriously by the public. Second, the recent El Niño was remarkable in its magnitude and duration. Third, although globally costs and damages were attributable to the El Niño, in the western United States, costs were counterbalanced by positive effects such as the relatively mild winter and adequate precipitation for the arid West.

Several speakers reported that the long-range cool-season forecasts for North America were of unprecedented skill and usefulness. In a keynote address to the workshop, Martin Hoerling of the NOAA/Climate Diagnostic Center showed, with a judicious blend of historical analyses and climate-simulation experiments, that much of this success is attributable to the unusual magnitude of the tropical forcings during this El Niño, a magnitude that was large enough to overcome much of the uncertainty that historically has been typical of the extratropical outcomes of weaker El Niños.