29 September 2015 – PNW Migration Update

Migrants are still on the move.  A fairly heavy movement was picked up on the ATX station (Seattle) radar.  It was a bit more moderate down here in the Metro Area (RTX), and concentrated in the east counties.

I sill haven’t resolved the disc space issue.  But, i am leaning toward starting a new blog with forward and backward references.  I would like the new blog to be as robust as this one (information pages and reference links) but that will take a lot of time to do.  So it will be an “off-season” project.  Which means the real purpose of this current blog – to leave an archive of the radar images – has reached its unfortunate and technical end.

So, this is the second to the last post for this blog.  The next one will be with a link to the new blog.  But i’m not sure when that will be.

In the mean time, all of the tools you need to track migration can be found in both the “Pages” section and in the links on the right hand side of the page.

23 September 2015 – PNW Migration Update

Neutral conditions of light variable winds and clear skies — moderate migration.

A well organized low pressure system is spinning up in the Gulf of Alaska.  We’ll keep an eye on that as it moves west east because the leading edge will definitely put the breaks on.

Well — i knew it was coming, I’ve reached the end of my allotted memory so i can’t post any loops or images today.  I have a few options that i have to mull over.


22 September 2015 – PNW Migration Update

Welcome to Fall.

Birds were jamming last night!  Decent conditions, light northerly winds on a clear night across the Pacific Northwest.

The grand passage of the Greater White-fronted Geese yesterday – wow!  Probably a once in a lifetime experience. From the Portland Basin to the Southern Coast reports came in of GWFG in the thousands passing overhead.  A remarkable event.

Anyway i added the Seattle radar loop today because it was packed with birds and i don’t think i’ve posted one from there this season.  So here it is, your moment of zen:

Oh, look at the RTX loop and see if you can spot the Barn Swallows going to roost,  Starts around 00:00 UTC.


21 September 2015 – PNW Migration Update

I just got back from a walk around the block, specifically to listen for migrating Greater White-fronted Geese.  They were streaming overhead, flock after flock, non-stop.

Which brings us to today’s radar loops.  The RTX loop is very interesting.  Shortly after sunset there was a small but noticeable flight out of the area for about an hour or so, and then — nothing of note.  That is until around 2:30 AM (PDST) and BOOM!  The sky is just filled with returns up to the 30 dBZ level.  I suspect a majority being Greater White-fronted Geese.

I also threw in the Gray’s Harbor (LGX) loop because this is the largest sustained flight i’ve seen this season from there.

Note the wind map and the favorable winds out of the NNW.


18 September 2015 – PNW Migration Update

With the rain moving through, and the low pressure trough moving on, we had some decent conditions for migration.  And indeed, some migrants took advantage of the situation.  It wasn’t spectacular nor sustained, i would call it moderate.  The east counties saw the bulk of the action.  The high Cascade lakes might be quite productive for birding; loons and grebes are probably still moving through.


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.

15 September 2015 – PNW Migration Update

In spite of decent conditions, migration in the area remains tepid at best.

So, lets look elsewhere.  Today we’ll look at the national level and one curious spot. Nationally take a look at the Wind map, note the strong flows up the Central and Mississippi Flyways, and then note the paucity of migrants.  The east coast, with milder conditions, dominates the scene last night.  Since we showed Jacksonville recently i’m leaving that out, but it was jamming again last night with returns again pushing the 40 dBZ levels.

So, take a look at the loop from El Paso, TX from last night.  What i am curious about is the ring of returns that pops up for about an hour — just before avian migration takes place.  Look for it in the lower center of the frame over in Mexico.  I’m GUESSING, bats.  But, if anyone knows for sure – let me know.  Whatever they are, there are a ton of them dispersing from a single point.


14 September 2015 – PNW Migration Update

We still have a nice weather pallet for migration; light winds mainly out of the north, no rain, and a persistent, but weak, high pressure ridge out in the Pacific.

But, movement is moderate at best here in the Pacific Northwest.  It’s one of those days where i go looking for the hot spots; pull up Paul’s archived image from last night, look for the action, and then pull up the loop from that station.  And that’s how the town of Jacksonville Florida ends up in the tag cloud.

Here it is, your moment of zen:

Yeah, those returns are pushing 40dbz, for a significant amount of the night — MILLIONS of birds on the move.

11 September 2015 – PNW Migration Update

The ridge of high pressure remains in place – sort of.  It has been displaced a tad more out into the Pacific and that may account for the easterly offshore flow.

Whatever the case, migration last night was unremarkable and ended quite early.  I think this is just a pipeline issue as there has been some significant weather up north, probably holding back the migrants.