PWM has reports from the Jetport since 1931 ('31-'40 overlapped with Exchange Street downtown to verify consistency). 1940 officially moved to the Jetport, and moved twice with the terminal building, once in 1940 and again in 1988, then automation began in 1994 when we moved to GYX. The Jetport itself is pretty susceptible to west winds for blowing/drifting.
I can't seem to find the info prior to 2010, but the current snow observer is 2 miles NE of PWM (Deering neighborhood). It's not the best snow location in the sense of obstructions, not like Winthrop sticking out into Boston Harbor.