Hurricane Sandy will probably grow into a “Frankenstorm” as it nears the Northeast early next week with wind and rain that may cause millions of dollars in damage anywhere from Washington to New York and Boston.

Although the Grand Strand isn’t expected to encounter that kind of havoc, the chance of weekend events being washed out by the storm continues to grow as it moves north at about 16 mph.

The chance of rain and heavy wind Saturday was listed anywhere from 76 percent to 90 percent on different weather service websites.

A Thursday afternoon report by Steve Pfaff, a warning coordination meteorologist with the National Weather Service in Wilmington, predicted that the coastal area would receive from 2 to 3 inches of rain from the storm. Outlying areas, such as Conway, Loris and Aynor, were expected to receive between 1 and 2 inches.

The rain could tie a knot in CREATE! Conway’s scheduled yarnbombing event on Saturday, but a makeup date has been set for Sunday. Those interested in attending can call 248-3558 for updates to the schedule.

“I’ll be at that phone most of Friday and Saturday morning,” CREATE! director Barbara Streeter said. “We hope for the best.”

Another festival that will go on despite any rain is the North Myrtle Beach Endless Summer … at least the musical portion.

“We plan on moving the bands into the OD Pavilion,” said North Myrtle Beach Chamber of Commerce Community Programs and Events Director Charlene Lynam.

Lynam was unsure how they would proceed with the carnival games, rides and animals scheduled to be at the event, but encouraged those planning on attending to call her at 361-3045 for updates.

One of the larger adult events, the Celebrity Square Costume Contest at Broadway at the Beach scheduled for 8 p.m. Saturday, had its plan in place Thursday.

“Right now, it’s still on,” Said Lynn Black, controller of Celebrity Square. “Obviously, if it’s pouring the rain, we won’t have it. But if it rains during the day and clears up in the evening, we’ll still have it.”

Halloween revelers planning on attending can call 444-8032 for updates on the event, but a rain date for 8 p.m. Nov. 3 has been set just in case Sandy’s rain settles in longer than expected.

Sandy, a Category 2 storm with winds of 105 mph, will begin to transform into a hybrid system as it closes in on the East Coast, said Tom Downs, a forecaster at Weather 2000 Inc. in New York.

“The guys in the government are calling it ‘Frankenstorm'” because it will be a hybrid between a tropical system and a nor'easter, Downs said. “It is safe to say that there will be millions of dollars in damage.”

Sandy damaged at least 3,000 homes in eastern Cuba, along with coffee and tomato crops, according to Air Worldwide, a catastrophic modeling firm in Boston.

On Jamaica, where Sandy hit Wednesday, 70 percent of the island lost power, roofs were torn from off homes and roads were blocked by downed trees and floods, according to Air Worldwide.

A hurricane gets its power from warm ocean waters, while a nor'easter gains strength from differences in air temperature, Downs said. Sandy, a big, warm tropical system, is going to collide with cold air and low pressure along the eastern U.S., combing the elements of both.

“So this is going to be a hybrid storm with wind flow over a wider area than a hurricane,” Downs said by telephone. “You're not going to experience the massive damage in a concentrated area. Any damage is going to be more widespread but it isn't going to be as catastrophic as a hurricane.”

The amount of damage the East Coast is going to absorb is hard to estimate because the storm's track is in a state of flux, said Tom Larsen, senior vice president and product architect at Eqecat Inc., a risk modeler in Oakland, Calif.

Larsen said he doesn't expect Sandy to be worse than Irene, which struck the East Coast in August 2011, killing at least 45 people and causing at least $15.8 billion in damage, according to the hurricane center.

“Right now, in terms of loss levels, Irene is the best kind of guideline,” Larsen said. “It doesn't look to be a whole lot worse than Irene.”

Because weather models keep changing, Sandy's official track will change as well, Downs said. The hurricane center warns that tracks are just estimates and subject to change.

“Regardless of the exact track of Sandy, it is likely that significant impacts will be felt over portions of the U.S. East Coast through the weekend into early next week,” Michael Brennan, a senior hurricane specialist at the center in Miami, said in a forecast analysis.

The storm may hit anywhere from the mid-Atlantic states starting Oct. 28 to southern New England later in the week, said Gary Best, a meteorologist for Hometown Forecast Services Inc. in Nashua, New Hampshire.

Todd Garvin, tgarvin@thesunnews.com, contributed to this story.