As expected, Republican Joe Carvin will announce his plans to run against longtime Democratic Rep. Nita Lowey tomorrow with businessman Mark Rosen planning to drop his bid, a Westchester source confirmed this morning.

Rosen, a retired lieutenant colonel who considered running against Lowey in 2010, released a statement today saying that he planned “an important campaign announcement” Wednesday at 9 a.m. at an elementary school in his hometown of Larchmont.

Carvin launched a short-lived campaign for the Republican nomination for the U.S. Senate, but bowed out several weeks later at the state GOP convention in Rochester.

Word spread quickly at the convention that Carvin, the Rye town supervisor, was turning his attention to the House seat held by Lowey, which was redrawn north into a slightly more Republican-friendly area. We blogged yesterday that Carvin, who has the capacity to self-fund, was interested in the seat after his name recognition rose.

Though Westchester County has been considered a Democratic stronghold for years, the Republican Party is feeling its oats lately after Rob Astorino scored an upset victory over longtime Westchester County Executive Andrew Spano.

Still, Carvin is expected to face an uphill battle, given the presidential election in November.

H/t Joe Spector at Gannett Albany.