The new TV season has proven absolutely deadly for NBC's sophomore forensics drama, ''Crossing Jordan.'' At the end of last year the show easily won its Monday time slot in key demos and overall viewers, but all of a sudden it's getting sand kicked in its face by CBS rookie ''CSI: Miami.'' The David Caruso vehicle has attracted an impressive 21.5 million viewers, more than twice the typical 10 million turnout for the Jill Hennessy-starring ''Jordan.'' The story is the same among adults 18-49: ''Miami'''s winning, ''Jordan'''s losing -- but not by a large enough margin to prompt a move off Mondays. ''We had modest but realistic expectations for 'Crossing Jordan,''' says NBC head of scheduling Mitch Metcalf, who isn't overly concerned by the show's lackluster performance. ''We have to congratulate 'CSI: Miami,' though; it's brought new viewers into the time period. It's not all coming out of 'Jordan''s hide.'' Of course, NBC's coffers are in danger of taking a hit: The net's syndication arm, which is trying to hawk ''Jordan'' rerun rights to cable outlets, hasn't exactly seen its phone lines lighting up. ''Obviously, with the ratings down, that doesn't help,'' says Bill Carroll, VP of programming at Katz TV Group. Nevertheless, NBC is still pro-''Jordan.'' As long as it maintains current viewership levels, says Metcalf, ''this show will not ride off into the sunset.''