The National Weather Service hurricane tracking chart for 2013 tells the story: This year's Atlantic hurricanes were a series of squiggles that fizzled.
Seldom have so many forecasters agreed so completely on a prediction so wrong. In the run-up to the 2013 hurricane season, experts were all on the same page: Conditions were ripe, they said, for an active hurricane season in the Atlantic basin. The most likely scenario, they said, was a season with 15 to 18 named storms, 8 or 9 hurricanes, and 3 or 4 major hurricanes (see "Forecasters See Active Hurricane Season For 2013," Coastal Connection 4/11/13, and "NOAA: Active Hurricane Season Ahead," Coastal Connection 5/26/2013).
It didn't happen. An AccuWeather.com story sums it up: "As the 2013 Atlantic hurricane season ends Nov. 30, it marks the season with the fewest number of hurricanes since 1982, according to the National Oceanic and Atmospheric Administration," ("2013 Atlantic Hurricane Season Closes Without Any Major Hurricanes," by Jillian MacMath).
Hurricane expert Jeff Masters comments on the Weather Underground, "It was a bad year to be in the seasonal hurricane forecast business." (See Masters' full blog entry here: "The Unusually Quiet Atlantic Hurricane Season of 2013 Ends".) Masters explains that the signs favoring an active season were strong going into the summer: There was no El Nino pattern in the Pacific, ocean temperatures were warmer than average, sea level air pressures were below average, wind shear was average, and the African Monsoon was active, with many low pressure waves coming off the African coast of the type that often develop into hurricanes. But, Masters says, other factors that can't be pinned down early in the season, but that do make a big difference, worked against hurricane formation this year. Writes Masters: "This summer and fall, an unusually strong trough of low pressure over the Central Atlantic brought large amounts of dry, sinking air to the tropical Atlantic. Large amounts of dry air also invaded from the Sahara, and from Northeast Brazil, which had suffered the most expensive drought in Brazil's history ($8 billion) earlier in the year. The combined onslaught of dry air from these multiple sources was enough to overwhelm the otherwise favorable conditions for development, leading to one of the quietest Atlantic hurricane seasons on record."
The experts were left eating crow, reports the Sun Sentinel (see: "Why experts blew the 2013 hurricane forecasts," by Ken Kaye). Writes the Sentinel: "'I think the magnitude of the cooling that occurred in the Atlantic was somewhat overlooked by ourselves and others,' said Phil Klotzbach, who along with William Gray initially forecast 18 named storms, including nine hurricanes. 'It was one of the largest busts for our research team in the 30 years we've been issuing this report' … Because so many forecast teams misread the atmospheric signals, Klotzbach said, 'people will probably not put as much stock in seasonal forecasts next year. You're only as good as your latest forecast.'"
That's if Klotzbach and Gray even issue another long-range forecast next year. The Philadelphia Inquirer is reporting that they might not (see: "Hurricane season: Categorical bust," by Anthony Wood). Writes the Inquirer: "Bill Gray began issuing his long-term outlooks 30 years ago, and his methods have been copied elsewhere. But he and Klotzbach say they are having a funding crisis and it's possible that they'll be getting out of the business."