The Long Way to Boston/NYC

Any ideas on what might have happened on May 2nd? … /KSAN/KBOS
The flight usually takes ~4:45, but this one was in the air for 6:29. It must have been a heck of a weather system for that kind of diversion. It took off an hour late and landed 3 hours late. Wonder if it would have been better to go around the south end of the weather, like DAL 1660 did.
As I look at some more flights from that day, I see it was indeed a long roundabout day for many.
AAL 160
DAL 98
JBU 188
These guys had Rapid City and Aberdeen, SD in their flight plans on this day, which pretty much never happens coming from San Diego. And for good measure, looks like they all had some kind of hold over Wyoming. I guess everyone else wanted to go that way too, causing a slight logjam.

Big ole honkin low with a trailing cold front laden with severe thunderstorms will muss up the traffic flow. … 80502.html