The Atlantic Ocean could be headed for record warmth come summer. But halfway to the June 1 official start of hurricane season, forecasters say the climate factors are too uncertain to guess how threatening the patterns might become.
One difference maker would be how hot the Atlantic waters become in the tropics where hurricanes tend to form, said Phil Klotzbach, lead scientist of the industry benchmark Tropical Meteorology Project.
"Most of the discussion has been surrounding the potential for record warmth in the subtropical instead of the tropical Atlantic," he said. "The strongest signal between Atlantic hurricanes and sea surface temperatures is in the tropical Atlantic."
Those temperatures are trending slightly above normal, he said.
Hotter seas mean more fuel for stronger hurricanes. Hurricanes draw heat off sea surface to keep churning.
The other big early signal would be if El Niño conditions emerge or not, said meteorologist Jeff Masters with Weather Underground.
El Niño is a Pacific Ocean warming. The winds stirred by the warming tend to disrupt hurricanes in the Atlantic.
Computer model predictions diverge on whether El Niño will warm, he said.
"There are currently no major warning signs pointing to the possibility for a very active Atlantic hurricane season," Masters said.
The June to November season looms as federal specialists and other forecasters race to catch up on research delayed by the partial government shutdown in January.