I read on Facebook Brooklyn Urban Birders group that Shane Blodgett saw the rare gull on the ice away from the western shore of Prospect Lake. the time wasn't mentioned.
I forgot to note previously that with the appearance of three rare gulls within a time span of two weeks is truly astounding for prospect:pretty hot out there on the cold waters. ( Iceland gull on Dec 26th, Blackheaded all along, Thursday's Lesser Black backed gull)