Based on numbers of expected storms, hurricanes and major hurricanes and not factoring in potential impact to land, 2012 is expected to be less active than last year.
There are a couple of factors that have led the AccuWeather.com Long-Range Forecasting Team to forecast lower numbers of named storms this year.
Starting Out with Less-Favorable Conditions
Compared to 2011, this Atlantic Hurricane Season will start out with a less-conducive environment for tropical storms to develop. The official start of the season in the Atlantic is June 1.
Strong high-level winds are in place over the western and central Caribbean, promoting increased wind shear. If these high-level winds do not abate, increased wind shear will inhibit tropical storm development early in the season.
Strong wind shear, which is the change of wind speed or direction with altitude, causes building clouds to be tilted, restricting vertical development. Unless a tropical system has a vertically oriented core, its ability to develop are diminished.
The surface pressure across the Atlantic is not as low as it was in 2011, when there was below-normal surface pressure across the Caribbean. The surface pressure is now near to above-normal in the same region.
When surface pressure is lower, it promotes tropical storm development.
"If numbers are low early in the season, then overall numbers for the entire season will turn out lower than the forecast," AccuWeather.com Expert Senior Meteorologist Dan Kottlowski cautioned.
Transition into El Niño
A shift into an El Niño pattern is expected by the peak of the Atlantic Hurricane Season, which occurs around Sept. 11. El Niño is a phenomenon classified by above-normal water temperatures in the central and eastern equatorial Pacific Ocean. It is often associated with diminished development of tropical systems in the tropical Atlantic.
A favorable set-up for tropical development in the Atlantic features a large area of high pressure over the central Atlantic with strong westerly winds located farther north.
"A change to El Niño forces the westerlies to migrate farther south, causing increased [wind] shear that will diminish or perhaps shut down further development beyond September," Kottlowski said.
Conditions are worsening across Bermuda ahead of Major Hurricane Joaquin passing dangerously close to the island nation to end the weekend.
An intense band of heavy rainfall will continue across South Carolina and parts of North Carolina, bringing storm total rainfall across some areas over one foot.
Lives and property will continue to be threatened in and around South Carolina through Monday as additional torrential rain pours down, further worsening already major to catastrophic flooding.
According to the BBC, the Brague River overflowed its banks, sending water into nearby towns and cities, including Cannes.
Tropical cyclones presented trouble around the world this week, while heavy snow fell in parts of Alaska.
Mujigae will bring flooding and strong winds to parts of southern China early next week.
Kansas City, MO (1998)
4.24" of rain.
Brampton, MA (1673)
"There was a storm of rain and snow so that the ground was covered with snow, and some of it continued to Oct. 6th." C. W. Chase, hist. of Haverhill. Early snow of the century.
Philadelphia, PA (1777)
Battle of Germantown: "It had been misty at sunrise. The mist thickened into fog; the fog grew more dense." Great confusion ensued, American troops fired on each other and the battle was lost.