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.


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.

10 September 2015 – PNW Migration Update


Another solid night of migration.  This high pressure ridge just wants to stick around.  That brings gentle winds out of the north and makes excellent conditions for southbound migrants.

Greater White-fronted Geese, Sandhill Cranes, and more winter sparrows are all being reported in the area.  It’s a good time to get out into the field.

Here it is, your moment of zen:


04 September 2015 – PNW Migration Update

Another solid wave of migrants moved through, and into the area last night.  Not quite as robust as yesterday, but still decent.

The drop in density is probably due to the nature of yesterday’s event.  When migrants are held up for a while i suspect they build up a bit of “pressure”; in both numbers and urges.  So that when the weather conditions change favorably, they kind of pour forth to relieve the pressure.

You can see from the wind map our weak high pressure system is still in place giving us these calm winds out of the north.  It looks like this will persist for a day or two as well.

I put in the National Composite today — take a look at the west side of Lake Michigan!  From Green Bay to Chicago the movement was extreme.  Heavy yellow returns across the board.  To save space i did not put up a loop from either of the three stations, but if your curious what a mega event looks like take a look at Green Bay’s loop on the DuPage Weather Lab.  I did archive the loop and may put it up later if there is nothing going on here.


2015 Fall Migration Update

Well, here we go again.

I will not be starting daily updates quite yet, but i did want to get a post up.  We’ve been seeing moderate levels of migration over the past couple of weeks.  It seems to be mainly centered on the western flanks of the Cascades but trickling down into the valley as well.

Shorebirds have been well documented on their south bound journey in the local listserves, but that is not unusual.  Once the ducks start to show up i will probably post on a more regular basis.  Until then it will be hit or miss.

Via John Stewart, ” Here it is, your moment of zen.”

01 Apr 2015 — PNW Migration Update

Only the slightest sign of movement last night.  Dodging rain cells and fighting cross winds gets old.  There are better opportunities ahead.

San Diego area reports the first Gray Flycatcher, more Black-headed Grosbeaks and Orioles.

Central Valley shorebirds are increasing with the arrival of Black-bellied Plovers.

Willamette Valley has reported all of the swallows with the exception of Bank Swallows.  More Common Yellowthroats as well.