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ABSTRACT
The 1999 hurricane season in the eastern North Pacific is summarized, and individual tropical storms and hurricanes are described. Producing only nine named storms, the season tied 1996 as the second least active on record. Hurricane Dora was the strongest and longest-lived cyclone of the season. Hurricane Greg, the only cyclone to make landfall during the season, weakened to a tropical storm just before moving ashore in Baja California, Mexico. Fifteen deaths resulted from the tropical cyclones.
1. Introduction
The eastern North Pacific hurricane basin covers the area north of the equator and east of 1408W longitude to Central and North America. Nine tropical storms formed in this basin during the 1999 hurricane season. Of these, six became hurricanes and two became major hurricanes-category 3 or higher (maximum sustained winds of 97 kt or greater) on the Saffir-Simpson Hurricane Scale (Simpson 1974); the 1966-98 averages are 16 tropical storms, 9 hurricanes, and 4 major hurricanes. There were five additional tropical depressions that failed to reach tropical storm intensity. The 1999 season ties the 1996 season (Mayfield and Rappaport 1998) for the second least active since satellite observations began in 1966. Only the 1977 season, with eight tropical storms (Gunther 1978), was less active.
Table 1 lists the tropical storms and hurricanes of 1999, while Fig. 1 shows a map of their tracks. Most of the data used in determining the tracks and intensities (1-min average sustained winds at 10 m) are derived from satellites; these include Dvorak (1984) intensity estimates, cloud-driftwinds, and ocean surface scatterometer data (e.g., Tsai et al. 2000). Other sources of data include infrequent surface, upper-air, and radar observations. There were no reconnaissance flights into eastern North Pacific tropical cyclones in 1999.
Hurricane Greg, which crossed the southern tip of Baja California, Mexico, as a tropical storm on 7 September, was the only storm to make landfall in 1999. Hurricanes Dora and Eugene crossed 1408W into the central Pacific basin, with Dora later crossing the international date line into the western North Pacific basin.
One can speculate on the reasons for the inactive season. One possibility is the active 1999 Atlantic season (Lawrence et al. 2001), which featured 16 tropical cyclones (TCs). Climatologically, most eastern North Pacific cyclones can be...