NEW YORK — East Coast refineries are likely to close in advance of Hurricane Irene’s arrival this weekend, analysts say. The shutdowns are already boosting gasoline prices.

The storm pounded the Bahamas Thursday with winds of 115 mph and it could reach East Coast refineries, which are concentrated in New Jersey and Pennsylvania, by Sunday afternoon.

Refineries are already starting to turn off equipment and tie things down.

“Even if the storm eventually misses them, they can’t take chances,” says Ben Brockwell at the Oil Price Information Service, which monitors fuel shipments around the country.

Refineries are sprawling complexes of concrete and steel that turn oil into gasoline, diesel and other kinds of fuels. While the main buildings are designed to withstand hurricane-force winds and earthquakes, some of their pipes, cooling towers and power lines are susceptible to wind damage. Utilities are expecting widespread power outages from winds and downed trees.

It takes several days for a refinery to start operating again following a shutdown. And many would need almost a month to get back to full operation.

Gasoline futures rose nearly 2 percent Thursday.

Tom Bentz, an analyst at BNP Paribas Commodity Futures, said traders are betting that supplies may be squeezed.

“There’s the potential for certainly coastal flooding, potential for refinery outages, potential for shipping delays, things like that,” Bentz says.

Drivers should also see pump prices rise this weekend as Irene approaches. People are now paying anywhere from $3.37 a gallon in South Carolina to $3.91 in Connecticut. The national average is down 40 cents from its peak of $3.98 on May 5.

Shutdowns of more than a few days would put serious pressure on fuel supplies and prices. Fuel stockpiles are already low because distributors are preparing to switch to wintertime grades of gas.