"Wash." used to be the postal code for WA before we went to two letter abbreviations.
There were no standardized abbreviations before the US Postal Service created them. At best you had something like the Associated Press style manual for datelines. Canada Post collaborated (note that "MB" is the only possible abbreviation for Manitoba that doesn't overlap with a US state).
I'm surprised though that people are having such a hard time reading this (well, I can understand non US based people not getting it, but anyone in America who doesn't must lead an incredibly hard life, being so literal and all).
It's up there with there/their/they're and to/too/two: "WA" has a clear and unambiguous meaning and its incorrect use is jarring, interrupting the smooth flow of reading while we have to consciously decipher the writer's intent.
The newspaper's name is Washington Post, and the typical jargon shorthand is "WaPo." Anagama wanted to use jargon to sound "in the know" and instead made the source sound like a no-name local competitor to the Seattle Times.
I live in the real Washington