Air carrier First Officer reported an NMAC as alerted by a TCAS RA with a helicopter on approach to PHL. The Captain; who was the pilot flying; decided to continue the approach because of possible conflicting traffic if they executed a go-around.

Narrative

PHL was operating close parallel approaches that day on 27R and 27L due to heavy traffic and extremely high winds (290@27G40). We were assigned Liberty visual 27L; and proceeded as normal. Around 2;000 AGL; Tower called helicopter traffic at 11:00; below; maintaining visual; do we have them in sight. Captain and I both gained a visual; reported visual contact to Tower. Simultaneously; an air carrier was directly off our right wing coming in for 27R. Around 1;500' or so; the helicopter traffic triggered at TA. We both confirmed visual confirmation with each other; and continued. As PM; I never took my eyes off it for the next 30 seconds. About 5 seconds after the TA; the helicopter triggered an RA to climb. Captain and I both had a visual still; and communicated that to each other we have it in sight. Captain decided to not follow RA guidance to my surprise and continued on flight path. We came within 200 vertical feet of the helicopter traffic. The entire incident from TA to RA to clear of conflict lasted about 8 seconds. It happened very quick; but the separation was minimal. We landed stable with no issue. I later asked the Captain why he didn't follow the RA and he stated that we had visual on both traffic and climbing would have triggered another RA with the air carrier off our right. I do feel as though the helicopter was far too close to our arrival path and should have never been vectored that close to us or cleared into that airspace with close parallels in affect.Cause: Stop allowing and vectoring helicopters in low level corridors around and inside approach windows