While many of us have just thought about spring cleaning, hurricane season is right around the corner. In the eastern North Pacific, in a region extending from the western coast line of North America westward to a longitude of 140 degrees west longitude, the official hurricane season defined by the National Hurricane Center will commence in slightly more than two weeks (15 May to be precise). In a little more than a month the official 1999 hurricane season will start in the North Atlantic basin, which includes the Gulf of Mexico and the Caribbean. While a hurricane or other tropical cyclone may develop before the start of the new season on 1 June, such an event is rare. In the North Atlantic, the latest recorded hurricane was on 31 December 1954 and the earliest was on 7 March 1908.
The 1998 hurricane season in the Atlantic was one of the deadliest on record, as three major hurricanes caused more than 11,000 fatalities. In addition, four hurricanes (Georges, Ivan, Jeanne, and Karl) were simultaneously active, the first such occurrence since 1893.
As a preliminary review of the 1998 Atlantic hurricane season, 14 named tropical cyclones formed, representing either tropical storms or hurricanes - both types of systems are assigned a name, such as Bonnie, for identification purposes. Of these systems, 10 reached hurricane status, having winds in excess of 74 mph, while the other 4 reached only tropical storm status (with winds between 39 and 74 mph).
The first tropical system of the season was Tropical Storm Alex that formed 27 July 1998 and the last was Nicole, which formed on 24 November and had the distinction of being the first December Atlantic hurricane since 1984. One of the major hurricanes in the century of the Atlantic Basin was Hurricane Mitch, which had sustained surface winds of 180 mph and gusts estimated at more than 200 mph, the fourth strongest Caribbean hurricane this century. According to the National Hurricane Center, Hurricane Mitch, a category 5 hurricane, is one of the five deadliest hurricanes on record in the Atlantic Basin. The National Climate Data Center (NCDC) has prepared a report entitled "Mitch: The Deadliest Atlantic Hurricane Since 1780". Hurricane Georges, a Category 4 hurricane, was another intense system that had 150 mph sustained winds.
Six systems made landfall in the continental United States. In late August, Hurricane Bonnie hit North Carolina with winds reaching 100 mph. and caused at least $1 billion in damage. At approximately the same time, Tropical Storm Charley made landfall in Texas. As much as 18 inches of rain fell around Del Rio, causing flooding and killing at least 19 people in Texas and Mexico. On the Labor Day weekend, Hurricane Earl hit the Florida Panhandle, with 80 mph winds and nearly 24 inches of rain Earl was responsible for three deaths and approximately $25 million in insured losses. In early September rains from Tropical Storm Frances flooded more than 300 miles of Gulf Coast from Texas to Louisiana and caused one death. By mid September, Hurricane Georges, a Category 4 system started a westward trek across the North Atlantic and western Caribbean. Ultimately, Georges crossed the Florida Keys in late September and made landfall along the Mississippi Gulf Coast, with winds in excess of 100 mph. Several tornadoes were spawned along the Gulf Coast. At least three storm related fatalities were associated with Georges in the U.S., 350 deaths in Hispaniola and at least $2 billion in property damage resulted in four Gulf Coast states and the Caribbean. Tropical Storm Hermine barely attained tropical storm status in mid September before making landfall on the Louisiana coast. After making a track of death and destruction through central America, the remnants of Hurricane Mitch reintensified over the Gulf of Mexico and raced through Florida Keys as a tropical storm during the first week of November, spawning tornadoes and causing at least one storm related fatality in South Florida.
In the eastern North Pacific, the hurricane season runs from 15 May to 30 November. The 1998 hurricane season had 13 named tropical systems, with nine reaching hurricane status. Three of these hurricanes were Category 4. Howard was the strongest with 150 mph sustained wind. Only Isis made landfall, but only after weakening to tropical storm force.
The 1998 hurricane season was more active than usual in the Atlantic Basin. Using long term averages running from 1931 to 1996, a typical North Atlantic hurricane season would have 10 named storms, with nearly 6 hurricanes and 4 tropical storms. The active 1995 season - one of the most active on record - had 19 named systems, with 11 being classified as hurricanes and 8 tropical storms. The least active in recent history was 1982 when only 5 named storms were reported.
Several factors may be responsible for the active Atlantic hurricane season. The weakening of the El Niño episode in the eastern Pacific may be partly responsible. During last year's intense El Niño, the 1997 Atlantic hurricane season, had only seven named tropical cyclones formed, with three making hurricane status; additional information on the 1997 North Atlantic hurricane season can be obtained from http://www.nhc.noaa.gov/1997.html. Some researchers argue that an El Niño tends to suppress Atlantic hurricanes. According to Mark C. Bove of Florida State University, when an La Niña occurs in the Pacific Ocean, the chances of two or more hurricanes reaching the United States is 63 percent as compared to 48 percent in a normal year and just 28 percent in an El Niño year.
Dr. William Gray from Colorado State University in Fort Collins has been issuing long-range hurricane forecasts for more than a decade. His forecasts are based upon several factors that include analysis of the wind field at several levels, the rainfall over West Africa and the effects of El Niño. In April 1998, he issued a forecast for the 1998 season of 10 named storms, to include 6 hurricanes with 2 becoming major. At the end of November, Gray predicted that the 1999 hurricane season could be another above-average year in terms of the number and intensity of hurricanes. He blames it on the ``Atlantic conveyor belt,'' which circulates water from the tropics to the northeast Atlantic and back to the south along the North American continent.
Check Gray's Forecast prior to Season http://tropical.atmos.colostate.edu/forecasts/index.html
The 1998 season in the eastern North Pacific was near average. During the previous year, 16 named systems, eight of which were hurricanes. Four of these hurricanes reached Category 4 or greater. The larger number of hurricanes in the eastern North Pacific may have been related to the warm waters in the region associated with El Niño. Additional information on the 1997 Eastern Pacific hurricane season can be obtained from http://www.nhc.noaa.gov/1997epac.html