The 2013 Atlantic hurricane season looks set to go down as a bigwashout, marking the first time in 45 years that the strongeststorm to form was just a minor Category 1 hurricane.

There could still be a late surprise in the June 1-Nov. 30season, since the cyclone that mushroomed into Superstorm Sandy wasjust revving up at this time last year.

But so far, at least, it has been one of the weakest seasonssince modern record-keeping began about half a century ago, U.S.weather experts say. Apart from Tropical Storm Andrea, which soakedFlorida after moving ashore in the Panhandle in June, none of thisyear's cyclones has made a U.S. landfall.

That meant relief for tens of millions of people in U.S.hurricane danger zones. But 2013 has been a bust for long-rangeforecasters who had predicted a stronger-than-usual burst ofactivity in the tropical Atlantic.

It has been "a very strange sort of year" in the unpredictableworld of cyclones, said Jeff Masters, a hurricane expert anddirector of meteorology at Weather Underground.

"We've been in this multi-decadal pattern of activity but itjust didn't happen this year," Masters said, referring to theprolonged period of increased hurricane activity that began in1995.

That period is still playing out, fed primarily by warm oceantemperatures in the tropical Atlantic that fuel hurricanes. Butinstead of increased activity, 2013 almost seems like a year whenan enormous tranquilizer dart was fired into the heart of the mainbreeding ground for hurricanes.

A confluence of factors, including abundant sinking air and dryair, and possibly dust flowing out of North Africa's Sahara desert,kept a lid on hurricane formation in 2013, according to manycyclone experts.

That wreaked havoc with most leading seasonal forecasts like theone issued by Colorado State University on Aug. 2. The errantforecast said 2013 would see above-average activity, with eighthurricanes and three that would develop into major hurricanes ofCategory 3 or higher on the five-step Saffir-Simpson intensityscale.

An average season has six hurricanes and three major hurricanes.But an Aug. 8 outlook from the National Oceanic and AtmosphericAdministration called for six to nine hurricanes, three to five ofwhich would become major hurricanes.

There were two short-lived Category 1 hurricanes this year,making it the first Atlantic season since 1968 when no storm madeit beyond the first level of intensity, according to theNationalHurricane Center.

It has also been a year marked by the fewest number ofhurricanes since 1982 and the first since 1994 without theformation of a major hurricane.

In terms of so-called "Accumulated Cyclone Energy" (ACE), acommon measure of the total destructive power of a season's storms,2013 ranks among the 10 weakest since the dawn of the satellite erain the mid-1960s, said Dennis Feltgen, a spokesman for theMiami-based National Hurricane Center.

"The ACE so far in 2013 is 33 percent of normal," he said.

Long-range hurricane forecasts are eagerly awaited in U.S.financial and energy markets, which quiver every time a storm bearsdown on the U.S. oil and gas-producing region of the Gulf ofMexico.

Phil Klotzbach, a Colorado State University climatologist,readily admits that the forecasts are based on statistical modelsthat will "occasionally fail," since the atmosphere is chaotic andsubject to fluctuations that cannot be predicted more than a weekor two in advance.

But Klotzbach and other experts say the models, and seasonalforecasts, still provide useful insight into something asunpredictable as extreme weather even if they do not always panout.

"Obviously, individuals should not plan differently for aspecific season based upon a seasonal forecast," Klotzbach toldReuters by email. "They are purely there to satisfy the public'scuriosity based on our best knowledge of how large-scale climatefeatures impact tropical cyclone seasons."

Despite the season ending with a whimper, Masters saidlong-range forecasts are still worth betting on.

"They have a point, as long as you understand theirlimitations," Masters told Reuters.

"You expect that they will have bust years, like this year.That's part of the game," he said. "But if you consistently bet theway they're going, then eventually over the long run they'll payoff."