Massive Migration Occurring Aloft and Even Warmer on Saturday

 This is the season for northward bird migration and the weather is now perfect for northward flight.

As a result, there is a massive northward movement of birds occurring and the weather radars are lighting up with birds each night.

As I noted in previous blogs, many birds prefer to fly at night, so let me show you the regional radar imagery over the past 24 h.

5 PM yesterday (Thursday) there was nothing


At 2 AM, bird returns were everywhere with radar coverage.  Notice our birdy friends don't like to fly offshore.   You can also see where we lack low-level radar coverage, like the central and southern Oregon coast and eastern Oregon.  Oregon bird watchers need to complain!


This morning at 8 AM, the birds are gone.


I rarely show Dopper radar imagery (which shows winds towards or away from the radar), but here is last night's image from the Langley Hill radar in Hoquiam (the radar is in the center of the circles).  Green indicates the targets (birds) are approaching the radar, red shows targets moving away.

The radar targets are going northward!

 This is the season for northward bird migration and the weather is now perfect for northw Massive Migration Occurring Aloft and Even Warmer on Saturday

There is a nice website Birdcast, which collects all the radar information and shows migration patterns over the US.  Here is theeir graphic from last night, with arrows showing the direction of migration.  A large northward movement of birds along the West Coast.


I have noted that birds are a bit picky about nighttime flying weather.

They don't like heavy rain and stormy periods.  They also appear to appreciate a tailwind.  

And last night they had one.    Below are the winds overnight at 700 hPa (about 10,000 ft).  The little barbs show the direction and speed.  Southerly and southwesterly flow (from the south to the southwest) was apparent.  Not too strong.  Just like our feathered friends prefer.


Heatwave

    Today will get near 60F in western Washington and some places will get into the lower 60s on Saturday.  Take a look at the forecast surface air temperatures on Saturday at 5 PM (below).  Red is warmer than green and blue.  Wow.  Lower 60s all over the place in the western interior.


Warm southerly (from the south) winds aloft plus low-level downslope (easterly) winds over the Cascades are the reasons for the warmth.  This will be the warmest period since last October (see plot below, with 60F highlighted).  And it will feel good.

 This is the season for northward bird migration and the weather is now perfect for northw Massive Migration Occurring Aloft and Even Warmer on Saturday

Have a good St. Patrick's Day.



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