A government official says it’s the first major threat to Grand Isle, Louisiana in three weeks.  A massive oil slick, described as “a tremendous plume” by the official, on a direct course to hit the Gulf Coast in 24-48 hours.

The slick, photographed by a Fox Cameraman aboard a chartered helicopter, is 20 miles out in the Gulf but headed towards land.  It’s said to be 32 miles long and several miles wide, with “fingers” of thick crude stretching in different directions both at sea level and below.

The slick may be broken up by chemical dispersants dropped from planes, but the layers of defenses established by BP and government officials, including containment boom, barges and skimmer ships may not be enough to keep the oil from reaching land.

It’s expected to make impact by Monday night or Tuesday morning.