There is an endearing Yiddish version of the inflection.
The one to which this refers is certainly not Yiddish, which would not influence this group, it is the Valley Girl variety, I am sure, which, by media and pop culture, would influence this group.
I don’t find the Yiddish inflection endearing, myself. I maintain that it is the source of the Valley Girl variety. The S.F. Valley was colonized by a large influx of NY Jews.