Low dew point derechos are essentially organized bands of successive, dry downbursts. The Utah-Wyoming derecho of 31 May 1994 was an event of this type. It produced a wind gust at Provo, Utah, where sixteen people were injured, and removed part of the roof of the Saltair Pavilion on the Great Salt Lake. Surface dew points along the path of the derecho were about . Characteristics Winds in a derecho can be enhanced by downburst clusters embedded inside the storm. These straight-line winds may exceed , reaching in past events. Tornadoes sometimes form within derecho events, although such events are often difficult to confirm due to the additional damage caused by straight-line winds in the immediate area. With the average tornado in the United States and Canada rating in the low end of the F/EF1 classification at peak winds and most or all of the rest of the world even lower, derechos tend to deliver the vast majority of extreme wind conditions over much of the territory in which they occur. Datasets compiled by the United States National Weather Service and other organizations show that a large swath of the north-central United States, and presumably at least the adjacent sections of Canada and much of the surface of the Great Lakes, can expect winds from over a significant area at least once in any 50-year period, including both convective events and extra-tropical cyclones and other events deriving power from baroclinic sources. Only in 40 to 65 percent or so of the United States resting on the coast of the Atlantic basin, and a fraction of the Everglades, are derechos surpassed in this respect — by landfalling hurricanes, which at their worst may have winds as severe as EF3 tornadoes. Certain derecho situations are the most common instances of severe weather outbreaks which may become less favorable to tornado production as they become more violent; the height of 30–31 May 1998 upper Middle West-Canada-New York State derecho and the latter stages of significant tornado and severe weather outbreaks in 2003 and 2004 are only three examples of this. Some upper-air measurements used for severe-weather forecasting may reflect this point of diminishing return for tornado formation, and the mentioned three situations were instances during which the rare Particularly Dangerous Situation severe thunderstorm variety of severe weather watches were issued from the Storm Prediction Center of the U.S. National Oceanic & Atmospheric Administration.