Tropical storm warnings were in effect for a portion of the east coast of Mexico. No watches or warnings for the United States.
The center said Arlene would make landfall in Mexico early Thursday morning and was not forecast to strengthen into a hurricane.
Residents along the Gulf and East coasts should expect an above average Atlantic hurricane season, U.S. forecasters announced Thursday.
Between 12 to 18 named storms are likely during the season that typically runs from June 1 to Nov. 30, according to the 2011 outlook by the National Oceanic and Atmospheric Administration.
Of those six to 10 are likely to be hurricanes, and three to six of those could become major hurricanes, ranging from Category 3-5.
Last year's hurricane season was one of the busiest on record with 19 named storms, including 12 hurricanes.
But no major hurricane, i.e, Category 3 or higher, has made a U.S. landfall since Category 3 Hurricane Wilma struck Florida in 2005. Hurricane Ike caused extensive damage in September 2008 when it roared ashore in Galveston, Texas, but it hit as a strong Category 2 storm with top winds around 109 mph. Ike caused $10 billion in damage in Texas, Louisiana and Arkansas, making it the third-costliest storm after Hurricanes Katrina in 2005 and Andrew in 1992, according to the National Hurricane Center.
The lack of a major hurricane making U.S. landfall in recent years led officials to voice fear that locals won't take this season seriously.
"The United States was fortunate last year," NOAA chief Jane Lubchenco said in a statement. "Winds steered most of the season’s tropical storms and all hurricanes away from our coastlines. However we can’t count on luck to get us through this season. We need to be prepared, especially with this above-normal outlook."
The factors indicating an above average season were three, NOAA said:
An average season, as defined by NOAA, has 11 named storms and six hurricanes, of which 2 are major.
On April 6, Colorado State University researchers issued their own forecast, predicting an above average season of 16 named storms.
That’s one storm less than what the team forecast last December.