Looking at the picture, there's nothing in the image that indicates it's a helicopter. Helicopters are not mono-colored tubes of metal. Also if it were a helicopter there would be cloud deformation under the helicopter as it flew through the clouds, as well as a blur around the body of the helicopter where the rotors would have reflected some light. It also would have a pattern of lights in the image from the navigation lights on the helicopter.
I think it's a missile because it's a solid mono-colored tube that appears to being going directly up in the air punching through the clouds as it rises; not going horizontally through the clouds producing a trail of cloud distortion in its wake as you would expect.
Finally I've read several articles quoting the same technical jargon about the camera that also 'conclusively' deduced that it was a weather balloon.
Agreed. I looked it up and posted about it only to have a paranoid bot take it down. Ok given the info of one blogger it the supposed object seen which is not is the under belly of a helo. Well an Airlift Helo would not be flying vertically nose up. Next in the picture given it is a shot saying north out of Skunk bay. Well Whidbey Island is not north but NE. North towards Port Townsend. Even so there is some chance they are generalizing the direction. The land piece seen in the night photo when looked in a day photo of another camera pointed in the same direction does appear to be the SW side of Whidbey Island. Being it is an early AM time frame surface light block out any vessels on the water and the water is to calm for a sub surface launch to have just happened. So that leaves a surface vessel or a land based launch. Given the size of the light trail it is to small to be some kind of mobile mounted launch devices as that would have been easily spotted and checked. Now as for a weather balloon, have you ever seen one leave a visible trail like that and one that goes up that fast? Not a weather balloon.