Again, really, are you kidding me TriMet? Another alert received today.
“After thorough inspections and testing of the three WES trains overnight, it was discovered that blooms from cottonwood trees were clogging the air filters on the trains’ cooling systems and blocking the sensors needed to keep the trains in operation. The filters have been cleaned, and will be cleaned weekly while the cottonwood trees are releasing blooms. All WES trains will be running for the evening commute.”
In all honesty, this is starting to sound like the little kid making up excuses for not going to school.
Transit Sleuth 
Who knew that WES was allergic to pollen?
hahahaa. Yeah I know. I still wish the service well, especially since TriMet has to pay the contract no matter what – union and contracts and all being involved. But jeez, something this absurd shutting down the entire getup!?!?!!?
Agghhh!!
They are making this stuff up as they go along.