Forecasters with the National Oceanic and Atmospheric Administration (NOAA) said there is a 90% chance that this year's hurricane season will be below normal, but they added that while 2015 could be the third consecutive year for reduced hurricane activity, it was too early to tell whether it was the beginning of a trend that could last decades.
On Thursday, the NOAA's Climate Prediction Center, based in College Park, MD, said the 90% probability for a below-normal season was the highest confidence level given by NOAA since it began making hurricane outlooks in 1998. Last May, NOAA predicted a 70% chance for a below-normal season (see Daily GPI, May 27).
Gerry Bell, NOAA lead seasonal hurricane forecaster, said the below-normal hurricane season in the Atlantic was caused by three factors: a stronger El Nino; atmospheric conditions that are exceptionally non-conducive to tropical storm and hurricane formation; and tropical Atlantic sea-surface temperatures that are predicted to remain below average and much cooler than the rest of the global tropics.
Bell said overall storm activity was expected to be lower. NOAA was now predicting a 70% chance for six to 10 named storms (with wind speeds of 39 mph or higher), of which one to four could become hurricanes (74 mph or higher) and zero to one will become major hurricanes (Categories 3-5; 111 mph or higher).
So far this season, there have been three named storms in the Atlantic basin: Ana, Bill, and Claudette. The Atlantic hurricane season began June 1 and ends on Nov. 30.
According to Bell, eras of stronger or weaker hurricane activity in the Atlantic can last decades, typically averaging 25-40 years. The Atlantic has been in a high-activity era since 1995, but the last two years have seen reduced activity.
"It's still not clear if we're getting out of this high activity era," Bell said Thursday, adding that "for the last two years, the reduced hurricane activity was caused by mid-latitude weather patterns that were not linked to the longer-term climate signal. This year, the reduced activity is linked to El Nino. So while we've had three less-active years in a row, none of them appear to be linked to a change in the climate pattern that controls these periods for decades at a time.
"This is the first year that we've had a cooler Atlantic, and normally for a low-activity era we would have a cooler Atlantic for quite awhile. So, it's not clear to me and to a lot people if this isn't just a minor fluctuation in this overall active era, or whether it's actually indicated a switch out of that active era."
While increased natural gas production from U.S. onshore shale plays in recent years has lessened the potential impact of Gulf of Mexico (GOM) hurricanes on prices and supply (see Daily GPI, Sept. 18, 2013), production from the GOM still accounts for more than 3 Bcf/d or about 5% of supply. Total marketed natural gas production out of the Federal GOM has been on the decline since 1997, when it was 14.05 Bcf/d, according to Energy Information Administration (EIA) data. By 2014, that number had tumbled to 3.37 Bcf/d, and EIA estimates that it will continue to decline to 3.17 Bcf/d this year and 2.97 Bcf/d in 2016.
However, the EIA reported last week that gas production in the Federal Offshore GOM totaled 115.3 Bcf in May, a 7.2% increase from 107.6 Bcf of production in May 2014 (see Daily GPI, Aug. 4).