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39 < ~ z ~ ~ ~ z A tornado carves a path through the Oklahoma coulltryside lIear Cordell. A dozen others joined ill the May 22, 1981, outbreak ill western Oklahoma - about a fifth of the state's yearly total. On average, 900 twisters - some with winds approaching 500 kph (300 mph) - touch dowl1 in the midsectioll of the Ullited States each year. property. Damaging winds, lightning, hail, and ice that accompany these events kill thousands and cause billions of dollars in damage each year. These wind-related events can be dealt with more easily than severe tropical cyclones and tornadoes, but the extent of their occurrence is wider. Virtually no community in the world is immune. Prediction of catastrophic winds - whether associated with extra tropical cyclones, hur- ricanes, downslope windstorms, tornadoes, or thunderstorm gust fronts - involves forecasting on all time scales: long range (more than 10 days), intermediate range (3-10 days),. short range (1-3 days), very short range (a few hours), and "now- casts" (events in progress). Key to the utility of wind forecasts are timeliness, accuracy of loca- tion, and overall reliability. Key to their credibility are observations of current conditions that are accurate, quality controlled, and of high resolu- tion in both space and time, and good models of weather processes on the scales observed. In the near future, many nations need to invest substantially in modernizing their weather obser- vation nerworks. This effort involves deploying new satellites, Doppler radars, automated surface networks, and other technologies. It also requires new information management systems to inte- grate the data. Long-term prediction of the magnitude of extreme weather events permits evaluation of maximum structural loads and subsequent analy- sis of the economic viability of designing struc-