NOAA Forecasts Above Normal 2005 Atlantic Hurricane Season; Possible Impacts for Gulf Oil Production
NOAA has forecast a 70% chance of an above-normal 2005 Atlantic hurricane season season, a 20% chance of a near-normal season, and only a 10% chance of a below-normal season. This outlook is produced by scientists at the National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center (CPC), Hurricane Research Division (HRD), and National Hurricane Center (NHC).
The outlook calls for 12-15 tropical storms, with 7-9 becoming hurricanes, and 3-5 of these becoming major hurricanes. This prediction reflects a very likely continuation of above-normal activity that began in 1995.
The Atlantic hurricane in season in 2004 was above-normal, with 14 tropical storms, 9 of which became hurricanes, 6 of which became major hurricanes. In addition to other damage, the storms disrupted oil production in the Gulf of Mexico, adding unexpected supply stress to the oil supply-demand situation.
An important measure of the total seasonal activity is NOAA’s Accumulated Cyclone Energy (ACE) index, which accounts for the collective intensity and duration of Atlantic tropical storms and hurricanes during a given hurricane season. The ACE index is also used to define above-, near-, and below-normal hurricane seasons. A value of 117% of the median (median value is 87.5) corresponds to the lower boundary for an above-normal season.
The tumultuous 2004 season had an ACE index of 257% of the median; the forecast for 2005 ranges from an ACE index of 120%–190%. Above normal, but perhaps not as bad as 2004.
Hurricane seasons during 1995-2004 have averaged 13.6 tropical storms, 7.8 hurricanes, 3.8 major hurricanes, and with an average ACE index of 159% of the median.
NOAA classifies all but two of these ten seasons (El Niño years of 1997 and 2002) as above normal. In contrast, during the preceding 1970-1994 period, hurricane seasons averaged 9 tropical storms, 5 hurricanes, and 1.5 major hurricanes, with an average ACE index of only 75% of the median. NOAA classifies twelve (almost one-half) of these 25 seasons as being below normal, and only three as being above normal (1980, 1988, 1989).