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.
The risk of flooding downpours and gusty thunderstorms will increase across southern Florida as a tropical disturbance shifts northwestward from Cuba this weekend.
Stargazers will want to dig out their binoculars and telescopes this weekend as Venus and Jupiter shine so close that they appear as one large, bright star in the evening sky.
Typhoon Lionrock is poised to make landfall in Japan early in the new week with heavy rainfall, damaging winds and an inundating storm surge.
Hot and dry weather will greet fans and competitors at the 2016 U.S. Open Tennis Championships in Flushing, New York, as play begins Monday, Aug. 29.
Slow-moving and repetitive downpours will raise the risk for flash flooding along the western Gulf Coast into early next week.
Hawaii is facing not one, but two tropical threats next week as Madeline and Lester churn westward.
South Carolina (1893)
First of 3 great hurricanes that year in SC. Over 1,000 people drowned in tidal surge at Charleston.
Miami, FL (1964)
Hurricane Cleo battered South Florida area, the first direct hit since 1950. Gusts to 135 mph, barometer 28.57 inches. Damage at $125 million.
East Coast (1971)
Tropical Storm Doria paralleled East Coast, causing serious flooding. It also spawned a tornado in Cape May County, NJ.