UPDATE 01/21: Multiple letters sent with no response, and the pirate's still broadcasting. A letter has been mailed to the FCC's Enforcement Bureau. If you are an RIPR listener to 102.7 and you have experienced interference due to this pirate, you can submit your own letter to the FCC as well.
UPDATE 12/19: The pirate has been found! Well, we're pretty sure we have found the pirate. Using a directional antenna and a signal meter, we triangulated the position to a house a few blocks from the Locust Grove Cemetery in South Providence.
A letter of notification of interference to RIPR was mailed to this address several weeks ago, but apparently this pirate doesn't care as there's still an illegal broadcast on 102.9 from this location.
UPDATE 11/5: Thanks to a fellow engineer who informed me there is a pirate broadcasting on 102.9FM and that is likely the source of the interference people have reported (see below). Quite possibly the atmospheric changes made it worse, but the bulk of the problem is likely the pirate.