Birds Know That Summer is Ending Soon

 Here we are enjoying summer warmth, but other species know that ideal weather is ending soon.

How do I know this?

Birds have started to head south now in large numbers.

 One way I monitor bird migration is through weather radar, which picks up the movement of birds, with migration generally more evident at night.

For example, the radar this evening "lit up" with echoes after sunset....and this isn't rain.... It's birds (see below).

And by using the Doppler capabilities of the radars, we can determine the direction of flight.....to the south.   Here is a recent Doppler velocity image from the Camano Island radar:

Green indicates the target is approaching, red means moving away.  Thus, this Doppler radar image suggests movement to the south or southwest.

Then there is the BirdCast website, which heavily uses weather radar as a potent tool (below).  Lots of southward movement over the West.

Finally, the birds will have very nice flying weather for the next few days.   A significant ridge of high pressure has developed offshore (see map for 5 PM Sunday) that will bring warm, but not too warm, conditions over western Washington (mid-80s).

But this pattern won't last, and next weekend looks cooler with a chance of precipitation.