16 September 2015 – PNW Migration Update

The low pressure system that has been spinning up in the Gulf of Alaska has dipped down and brought southerly winds and a little rain with it.

These conditions are not conducive to migrants headed south and the rain cells obscure radar returns.  And that is a perfect time to look at the Hydrometeor Classification filtered returns.  In this mode we can see some biological activity, presumably avian, in last night’s loop.  It’s very low level but noticeable. (brick red signal – “BI”)

Cackling Geese are now being reported, a few more Golden-crowned sparrows, increases in Sandhill Cranes and shorebirds are still on the move.