(Portland, OR)  --  Police are searching for a missing and endangered woman who might be in downtown Portland.  The Washington County Sheriff's Office says 60-year-old Anna Short of Cedar Hills was last seen yesterday afternoon.  Police say a TriMet driver reported possibly seeing her getting off a bus at West Burnside Street and Southwest 2nd Avenue downtown last night.  Police say Short is endangered because she's new to the area and because of the freezing temperatures hitting Portland.  She's described as five-foot-three with a medium build and graying brown hair.