MIAMI, FLORIDA (BNO NEWS) -- Tropical Storm Alberto formed off the U.S. state of South Carolina on Saturday afternoon, prompting a tropical storm watch along the coast, forecasters said. It is the earliest tropical storm to form in the Atlantic basin in nearly a decade.
Forecasters at the U.S. National Hurricane Center (NHC) have been following the weather system since Saturday when it emerged as a non-tropical area of low pressure southeast of Myrtle Beach in South Carolina. It quickly began to acquire tropical characteristics before becoming a tropical storm on late Saturday afternoon.
As of 11 p.m. EDT (0300 GMT Sunday), the center of Alberto was located about 110 miles (180 kilometers) southeast of Charleston, the county seat of Charleston County and the second-largest city in the state. It is moving toward the southwest at nearly 6 miles (9 kilometers) per hour.
Maximum sustained winds of Alberto are near 50 miles (85 kilometers) per hour, with higher gusts. Despite being over relatively warm waters, only modest if any intensification is expected due to the system being situated in a marginal thermodynamic environment for strengthening with a markedly dry continental airmass to its north and west over the eastern Carolinas.
"The intensity of Alberto has been difficult to decipher this evening," said James Franklin, branch chief of the Hurricane Specialist Unit (HSU) at the NHC. "While an earlier SHIP (Statistical Hurricane Intensity Prediction Scheme) report suggested the storm was stronger, the satellite and radar representation has been on the decline since then, with a notable decrease in winds from the coastal doppler radars."
Alberto is unlikely to make landfall in the United States, but its effect may result in tropical storm conditions along the coast of South Carolina on late Sunday or Monday. As a result, the National Weather Service (NWS) has issued a tropical storm watch from the Savannah River to south Santee River in South Carolina.
"Alberto appears to be moving southwestward at about 5 knots, as it is being steered primarily by a low- to mid-level ridge over the eastern United States," Franklin explained. "This ridge is expected to break down in a day or so, with a complex steering flow probably causing the cyclone to turn toward the northeast in a couple of days. The guidance envelope has shifted somewhat to the southwest in this model cycle, though most of the reliable models still keep the storm offshore."
Tropical Storm Alberto is the first tropical cyclone of the 2012 Atlantic hurricane season, which officially does not begin until June 1. "Alberto is [the] earliest-forming tropical storm in the Atlantic basin since Ana in 2003," said NHC senior hurricane specialist Michael Brennan. "This is also the first time that a tropical storm has formed before the official start of the hurricane season in both the Atlantic and East Pacific basins."
Brennan was referring to Tropical Storm Aletta which formed far off Mexico's Pacific coast on Monday evening, hours before the 2012 Eastern Pacific hurricane season officially began. NOAA's Climate Prediction Center is expected to release a detailed forecast for this year's hurricane seasons next week.
An average Atlantic hurricane season produces eleven named storms, with six becoming hurricanes and two becoming major hurricanes. The Atlantic hurricane season runs from June 1 through November 30, with peak activity in September.
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