Air Carrier Captain landing Runway 16 at BLI reports being affected by jet blast from a large turbine powered aircraft being runup with the tail angled toward the runway.

Narrative

On very short final to Runway 16 aircraft suddenly and unexpectedly encountered a 'windshear/windshift'. Due to the very stable air and conditions prevailing at the time of landing this event was completely unexpected. As the 'windshear' occurred it took a very aggressive burst of power to arrest the sudden and unexpected descent rate that occurred due to the 'windshear'. Aircraft control was maintained and we landed uneventfully other than a longer than desired touchdown. After clearing the runway we overheard a conversation with an aircraft and the tower discussing a high-power engine run. As we taxied to the gate we noticed there was a turbine powered aircraft parked with it's engine exhaust pointed at what appeared to be an approximate 45 degree angle to the approach zone for Runway 16. As soon as we were aware of the cause of the unexpected 'windshear' on final I asked my First Officer to communicate with the Tower that this was not a good practice. Unfortunately I came away with a distinct impression that the controller really didn't seem to care about this as he appeared to laugh after my First Officer told him run ups in this area weren't a good idea. I have several concerns as a result of this: (1) I am concerned that the FAA and the Port of Bellingham have not designated a specific area on the airport for high power run ups for transport category aircraft. (2) It appears to me that the FAA has failed to properly train controllers on the hazards of jet blast on landing and departing aircraft. (3) No warning or notice was given by the FAA ATC facility to warn landing and departing aircraft of the fact that a transport category aircraft was performing a high power engine run up that was blowing jet blast across the landing zone of the runway.