The low pressure system has dropped south giving us winds with a strong northerly component instead of the westerlies we’ve been getting. (Compare today’s and yesterday’s 850mb wind plots.) And with north winds and no precipitation — we get birds! Not many and mostly leaving, but still, birds.
I put in a couple of of velocity plots. One taken at around 10:00 PM and the other around midnight PDST. In the one at 10 you see mostly movement away from Portland but by midnight we have some birds showing up coming from the south.
Migrants can also be seen on the move along the stretch of the Pacific Flyway to our south.
The national picture is playing out pretty much as laid out yesterday. The storm front is slowly moving east and the migrants are on the move — weather permitting. Texas and surrounding Gulf Coast; the southeast Atlantic; the mid-Atlantic; and some spots in the mid-west having the most density. Oh, and Minot ND – again.
The spotty nature of this migration pattern probably has to do with local weather conditions and that it is still rather early in the procession north.