The 2013 Atlantic season has delivered the fewest hurricanes since 1982, despite forecasters predicting in May that it would be a busier than normal year.
“It was a busted forecast,” said Chris Landsea, a forecaster at the National Hurricane Center told the Associated Press. “We did not anticipate it to be a quiet year.”
Forecasters had predicted 13 to 20 named Atlantic storms, seven to 11 that strengthen into hurricanes and three to six that become major hurricanes during this year’s hurricane season, which draws to a close on Saturday.
In Cayman, Director General of the National Weather Service Fred Sambula agreed that predictions had fallen woefully short of reality.
“It wasn’t even close,” he said.
Explaining what happened, he started by challenging the public’s concept of “predictions.”
“Predictions are just that,” he said, “and just because it’s been predicted, it doesn’t have to come true. Now we have to consider something new.”
That “something new,” he said, is the massive dust and sand blowing off North Africa’s Sahara Desert, the chief reason that local forecasters and the U.S.’s National Oceanic and Atmospheric Administration were so far off on the 2013 hurricane season.
“This time around, we had a lot of Sahara dust that persisted for quite a long time, and that kept the sunshine from heating the ocean. NOAA has said they will have to pay attention to this – and it just goes to show that we don’t know everything,” Mr. Sambula said.
If he sounds like a typical weatherman seeking to excuse inaccurate predictions, he is not alone.
NOAA had also predicted a 70 percent chance that 2013 was going to be more-active than an average hurricane season, pegging at 5 percent that it would be a quiet year.
The 13 named storms were exactly as forecast, but only two, Ingrid and Humberto, became hurricanes. Neither was considered “major,” a storm that reaches Category 3, boasting wind speeds between 111 and 129 mph that can cause devastating damage.
Forecasters also said this week that drier-than-expected air, persistent conditions in the atmosphere over the Gulf of Mexico, the Caribbean and the tropical Atlantic Ocean, led to the weaker season, which starts June 1 and ends Nov. 30. A normal year has 12 named storms, six hurricanes and three major storms with wind speeds more than 110 mph.
NOAA says 2013 will rank as the sixth least-active year since 1950, in terms of the collective strength and duration of tropical storms and hurricanes.
“Right now, we cannot even predict the speed of winds in hurricanes, when they will change and what they might do,” Mr. Sambula said. “We just don’t have that handle.”
Only one storm, Tropical Storm Andrea, made landfall in the United States, bringing tornadoes, heavy rain, and minor flooding to portions of Florida, eastern Georgia and eastern South Carolina, causing one death, NOAA said.
Unlike the U.S., Mexico was battered by eight storms, including three from the Atlantic basin and five from the eastern North Pacific.
Mr. Landsea said that in the Atlantic, hurricane activity tends to come in cycles, with the U.S. being in an active cycle that began in 1995. The cycles last from 25 to 40 years, so it’s unclear whether 2013 will be harbinger of things to come.
“We’re doing the research right now,” Mr. Sambula said, on 2014 storm cycles, “and even with so much dust from Africa, it still could be an active season. A normal season generated between three storms and four storms at most, and that’s the historical record. ‘Active’ is anything beyond that.”
“It may be that we’ll jump right back to a busy hurricane season, a lot of impacts, or it could be that we’re, you know, changing to a quiet regime again. We really don’t know,” Mr. Landsea said.
Last year was the third-busiest on record with 19 named storms. Ten became hurricanes and two were major storms, including Sandy.
“We’ll see what the experts say,” Mr. Sambula said, pointing to a February hurricane conference in Atlanta. “I’ll leave it to them and see what they say.
“It’s a good thing Cayman was spared this season, and every time a hurricane does not hit, we should give thanks.”
“It’s a good thing Cayman was spared this season, and every time a hurricane does not hit, we should give thanks.” Fred Sambula, Cayman Islands National Weather Service