El Niño was supposed to rip storms apart and put a damper on the hurricane season, but it appears to be a no-show.
As a result, there could be two or three more storms on top of an already bustling year. It leaves Florida more vulnerable, because October storms tend to form nearby in the Caribbean or western Atlantic.
"At this point, there is quite a bit of uncertainty as to whether an El Niño will even develop," said climatologist Phil Klotzbach. "If it does, it will probably be too late to impact the end of the season."
Klotzbach and Colorado State University colleague William Gray initially called for a tame season with 10 named storms, including four hurricanes, largely because they thought El Niño would develop. Several other forecast teams also predicted a slow season.
The average season sees 12 named storms, six of them hurricanes.
So far, 15 named storms, including eight hurricanes, have formed, putting 2012 in the top 10 busiest years on record. Two tropical storms hit Florida, Beryl in May and Debby in June, and Hurricane Isaac struck Louisiana in August.
Another storm might be brewing; models predict a disturbance in the Central Atlantic will grow into tropical depression by next week. It's too early to say where it might go, but if it develops it will be named Patty.
Despite El Niño's absence, lukewarm ocean temperatures and stronger than normal wind shear have made it difficult for strong storms to develop. There has been only one major hurricane, Michael in early September, and it never threatened land.
Rick Knabb, director of the National Hurricane Center, said it's difficult to predict whether El Niño will arise. "It's yet another leap to then try to forecast how many storms, hurricanes and major hurricanes will form," he said.
El Niño is spawned out of an abnormal warming of the eastern Pacific Ocean. It creates strong wind shear, which suppresses storm formation.
Because it can trigger chaotic weather around the globe, the National Oceanic and Atmospheric Administration issued an "El Niño watch" in June, as the pattern appeared on the verge of developing. But in recent weeks, the Pacific has cooled markedly, and NOAA has reduced the odds of the pattern emerging.
What happened? Primarily, westerly trade winds have remained strong over the tropical Pacific Ocean, disrupting the circulation of warm water to the region where El Niño forms, experts said. Jeff Masters, chief meteorologist of Weather Underground, an online weather site, thinks it will lead to the emergence of one or two more storms in the Atlantic alone.
"The Atlantic hurricane season is likely to extend into November, as has been the norm over the past decade," he said.
There is no set cycle when El Niño and its polar opposite, La Niña, form so next hurricane season could be calm or "it's also possible that we could have neutral conditions this winter and revert back to La Niña by next summer," Klotzbach said.