The Grinch” should continue to top the chart, but may be hanging by its fingernails as “Vertical Limit” tries to scale this weekend’s box office heights.

“‘Grinch‘ was down 48% last weekend from Thanksgiving. I would expect this weekend to drop maybe 40%,” an insider speculates. “That means it’s going to do around $16 million. It doesn’t look to me like ‘Vertical Limit‘ can get there.”

“I don’t think it’ll fall 40%,” another executive counters. “It’s falling less than that mid-week. If it falls 35%, it’ll do $17.5 million.”

Universal and Imagine Entertainment’s PG-rated comedy adventure blockbuster “Dr. Seuss’ How the Grinch Stole Christmas” has already grossed over $176 million. It should hit $200 million on Dec. 15 and be at about $215.5 million on Dec. 22. That would put it slightly ahead of “Mission: Impossible 2,” which now ranks as the year’s biggest film with about $215.3 million. “Grinch” is heading for $250 million-plus in domestic theaters.

Directed by Ron Howard and produced by Brian Grazer, “Grinch” stars Jim Carrey.

Columbia’s PG-13-rated mountain climbing action adventure “Vertical Limit,” opening at 2,307 theaters, should climb as high as second place with about $15 million.

“‘Vertical Limit,’ which I’ve heard such great things about, may be suffering from not really having a star,” an executive explains. “I think having an action star in that movie would have made a difference. But I hear it’s a good movie.”

“It’ll be in the teens unless it really breaks out,” another observer predicts. “They have a picture with no star. They’re releasing it on the perfect release date. Teenagers are ready for something. That’s why ‘Unbreakable‘ is doing so well. They think they’re going to get ‘The Sixth Sense‘ experience — and they’re not. There’s nothing else for them to see, so I think they will go out to see ‘Vertical Limit.’ The question is, could it do $18 million (and be number one)? I don’t think so right now.”

Directed by Martin Campbell, “Vertical” stars Chris O’Donnell, Bill Paxton, Robin Tunney and Scott Glenn.

Castle Rock and Bel-Air Entertainment’s R-rated suspense drama “Proof Of Life,” opening from Warner Bros. at 2,600-plus theaters, should finish third. Despite its star power, “Life” hasn’t been looking lively on Hollywood’s advance radar screens.

The real life romance that blossomed during the making of the film between stars Meg Ryan and Russell Crowe could hurt “Life” with women. “If there’s any kind of perception that there’s a broken home involved, I think it goes against Meg Ryan‘s image as sort of that wholesome, perky girl next door,” an insider says.

“The word of mouth is pretty bad already,” another studio executive points out. “It looks like $8-10 million. I think ‘Unbreakable‘ could almost out-gross it.”

Directed by Taylor Hackford, “Life” stars Meg Ryan and Russell Crowe.

Buena Vista/Touchstone’s PG-13-rated supernatural thriller “Unbreakable,” from the director and star of “The Sixth Sense,” was second last weekend with $14.4 million. A 45% drop now would give it about $8 million, making it third or fourth for the weekend. With its cume now at about $69 million, “Unbreakable” is on track to join Hollywood’s $100 Million Club by year end.

“I think ‘Unbreakable‘ will get hurt by ‘Vertical Limit,'” an insider comments, citing the two films’ appeal to teens.

Directed by M. Night Shyamalan, “Unbreakable” stars Bruce Willis and Samuel L. Jackson.

The weekend’s other wide opening, New Line’s PG-13-rated sci-fi action adventure “Dungeons and Dragons,” could battle it out for the fifth spot with Buena Vista/Disney’s live-action, G-rated sequel “102 Dalmatians.”

Dragons,” opening at 2,079 theaters, could come in with $6-7 million.

“There’s a good possibility that ‘Dalmatians‘ could still hold in fifth place,” a studio source says.

“It’s a kids movie, and my gut feeling is the ship has sailed on that (subject),” a distributor comments.

Produced and directed by Courtney Solomon, it stars Justin Whalin, Marlon Wayans, Thora Birch, Zoe McLellan, Kristen Wilson, Lee Arenberg with Bruce Payne and Jeremy Irons.

Directed by Kevin Lima, “Dalmatians” stars Glenn Close and Gerard Depardieu.

Filling out lower rungs: “Rugrats In Paris: The Movie,” “Charlie’s Angels,” “Bounce” and “Men Of Honor.”

On the limited release front: Sony Pictures Classics opens its PG-13-rated action adventure “Crouching Tiger, Hidden Dragon” in New York.

Dragon,” which has high hopes in terms of Golden Globe and Oscar nominations, was named Best Foreign Film by the National Board of Review, the first critics group to announce its honors for this year.

Directed by Ang Lee, “Dragon” stars Michelle Yeoh and Chow Yun-Fat.