Recorded presentation4.3
A societal/economic impact perspective of Rossby wave-train propagation for the extreme northern-hemispheric weather events of November 2002
Melvyn A. Shapiro, NOAA/Office of Weather and Air Quality, Boulder, CO
The high frequency of destructive weather events over the northern hemisphere during November 2002 was noteworthy, in light of its impact on society and its economies, as measured against losses in human life, destruction of property, and ecologies. These weather events included a tornado family outbreak over the eastern US; three periods of torrential rains and subsequent historic flooding over central Europe and North Africa; the eastern Atlantic cyclone that fractured the oil tanker off the coast of Spain; the devastating alpine wind storm over Austria, ice and snow storms over southeastern Canada; the major delay in the launch of the NASA space shuttle. The present study opens with a photographic essay of the societal/economic impacts of these events. This is followed by research results reveal that the extreme events were associated with three Rossby-wave trains circumnavigating the northern hemispheric extratropical latitudes, where the successive high-impact weather developed at the leading edge of the expanding Rossby-wave packets. The geographical location of high-impact weather propagated eastward around the hemisphere with the group velocity of their associated Rossby-wave trains. ECMWF deterministic and ensemble predictions demonstrate that advanced global prediction systems are capable of realistic simulations of the initiation and propagation of Rossby-wave trains for forecast lead times out to ten days and, on occasion, beyond. Though standard time/longitude plots (Hovmoeller diagrams) resolve Rossby-wave dispersion in both observed and predicted flows, they are typically prepared for latitudinal belts averaged over tens of degrees of latitude and therefore are of limited value in depicting ensemble forecast uncertainty in Rossby-wave ray paths. Recorded presentation
Session 4, Large-Scale Weather Systems (Room 617)
Monday, 12 January 2004, 4:00 PM-5:00 PM, Room 617
Previous paper Next paper