I'm no meteorologist, but I'm pretty sure it's raining overshoots!
Some sort of blocking high pressure system is in place somewhere - and we have high pressure here... Now I know I'm always preaching the good deeds of LOW pressure, but I feel like this may seriously work in our favour. And I mean seriously.... I'm really tired so I'll lay it out quick:
--- High pressure is blocking the weather patterns from moving much
--- the weather that we're getting "stuck" in for days is high pressure, that is centred below us
--- a big frontal boundry is stalled to our SW/W
--- this means south winds and clear nights... This isn't "suck a Red-faced Warbler from Arizona up in the Jet Stream insane mind blowing raritiy weather" like a huge low pressure system (storm)
----- BUT - as far as I can tell (my guess) this looks like AWESOME overshoot weather... For species like Kentucky, Worm-eating, Summer Tanager, Bell's Vireo, Painted Bunting (heck I think all of those have been seen in Ontario in the past two days during the start of this already!) But maybe some other species like Scissor-tailed Fly? Black-necked Stilt? SWAINSON'S Warbler?!
Bird is the word....