-- Although Andrew devastated South Florida in late August, it was the first hurricane of 1992, a season that overall turned out to be below normal.
-- In 2002, Gustav, the first hurricane of the season, didn't occur until September. Weeks later in early October, Hurricane Lili made a destructive landfall along the Louisiana coast.
There's also always the possibility of a freak storm after the season ends, says Vaccaro. "Nature sometimes throws us a curve ball as it has in the past when we've seen storms develop in the month of December."
How likely is it that the weather service forecast will pan out? In this crazy year, it's anybody's guess.
Hurricane watchers point out that there are more signs that something may be amiss:
-- The Accumulated Cyclone Energy index -- a rating system that compares the intensity of storm seasons -- would normally be around 55 for the Atlantic. It's now a paltry 16. Globally the rating is a stunning 255, roughly half of what we should see this time of year.
-- When an ocean basin kicks up a fuss on one part of the globe, usually another ocean basin is quiet. Nature tends to balance itself that way. This year, according to the ratings, storm activity in all the world's ocean basins is below normal. This adds even more to the mystery.
-- This year there is no El Niño, which would keep the season quiet, or La Niña, which would fuel a more active season. Atlantic surface temperatures continue to be above normal, which also would help stir up storms.
-- Climate change? As you might expect, opinions differ. Some researchers say global warming from the buildup of CO2 carbon gas pollution in the atmosphere will lead to more frequent and more powerful hurricanes. Some studies support that hypothesis, while others are less convinced. Although scientists are 95 percent sure that CO2 is warming the globe, they're not certain about how that affects hurricanes. "There are mixed signals," says Vaccaro. "So the jury's still out and research is ongoing."
At the National Hurricane Center in Miami, they're comparing this year to "a slow first half of a slow football game," says hurricane center spokesman Dennis Feltgen.
"It really doesn't matter how many storms form out there," Feltgen says. "If one gets to you, it's a bad year."
The news media isn't making too much of this strange season, he says.
But he warns, don't be fooled by it. Be prepared.
The mystery has grabbed the attention of Gray and other scientists, who are looking forward to analyzing all the data. Who knows? We may learn a few things.
"We'll figure it out," says Gray. "Let's see what the rest of the season brings."