One week after Valentine’s Day activities kept a chunk of viewers from watching primetime television, numbers remained low this Tuesday. Despite declines, ”NCIS” and ”NCIS: Los Angeles” kept CBS on top in key demos, but the net’s ”Unforgettable” is looking shaky.

According to preliminary national estimates from Nielsen, CBS opened the night an easy winner with ”NCIS” (3.8 rating/10 share in adults 18-49, 19.5 million viewers overall), down a tick week to week, and then stayed on top at 9 o’clock with ”NCIS: Los Angeles” (2.9/7 in 18-49, 15.9 million viewers overall), which dropped by about 10% from last week for a season low. And the downtrend continued at 10 p.m. for CBS with ”Unforgettable” (1.9/5 in 18-49, 10.6 million viewers overall), which skidded 17% week to week for a series low but still was the top broadcast draw for its hour in 18-49 and 25-54. As usual, CBS easily swept the night’s half-hours in total viewers.

At runner-up Fox, ”Glee” (2.9/8 in 18-49, 7.4 million viewers overall) was up a tick week to week but remained below average with its winter finale. It was followed by a below-average delivery for ”New Girl” (3.0/8 in 18-49, 6.2 million viewers overall) and ”Raising Hope” (2.1/5 in 18-49, 4.8 million viewers overall), both of which were in line with last week. ”New Girl” was the night’s No. 1 program among adults 18-34 (3.2/9).

NBC was up vs. recent weeks with ”The Biggest Loser” (2.3/6 in 18-49, 6.7 million viewers overall), which had one of its best scores of the current edition, and ”Parenthood” (1.7/5 in 18-49, 4.9 million viewers overall), which was up a tick week to week.

ABC was pretty much on par with its week-ago scores for ”Last Man Standing” (2.2/6 in 18-49, 7.5 million viewers overall), ”Cougar Town” (1.7/4 in 18-49, 4.5 million viewers overall) and ”The River” (1.7/4 in 18-49, 4.8 million viewers overall). And at 10, the net seemed to pick up some of the crime drama audience lost by CBS as ”Body of Proof” (1.4/4 in 18-49, 6.5 million viewers overall) was up from its season low of last week to finish within 1 share of the CBS and NBC dramas in 18-49. For the night, ABC was the only Big Four network up vs. the comparable night of last year.

At CW, a special repeat of ”Hart of Dixie” at 8 p.m. (0.4/1 in 18-49, 1.0 million viewers overall) fared the same in adults 18-34 (0.4 rating) as the 9 p.m. original of ”Ringer” (0.5/1 in 18-49, 1.4 million viewers overall).

Preliminary 18-49 averages for the night: CBS, 2.9/8; Fox, 2.8/7; NBC, 2.1/5; ABC, 1.7/4; Univision, 1.4/4; CW, 0.5/1.

In total viewers: CBS, 15.3 million; Fox, 6.5 million; NBC, 6.1 million; ABC, 5.8 million; Univision, 3.6 million; CW, 1.3 million.