07 Apr 2014 PNW Migration Update

The rains of the early weekend kept migration in opportunistic mode.  A few plucky souls would sally forth between the cells and scratch out a few more miles of northern territory.

Last night however, was a different story.  Mostly clear skies with just a breath of wind and we had 20+ dBZ returns across the Pacific Northwest.  I didn’t check the listserves over the weekend but i do have anecdotal field observations.

Water fowl numbers are way down.  There’s still thousands of white-cheeked geese in the area – probably turn over populations from the south.  I only saw a dozen Snow Geese and only heard a couple of Swans.  Dabblers and divers were counted in tens, if that, not hundreds.  The vanguard Osprey, Yellowthroats and Orange-crowns have been joined by the next wave.  There were a half a dozen Caspian Terns on Sand Island.  Nest building is in full swing among those taking up residence this year.   All in all – things are poppin’!

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

07 Apr Base Reflectivity - Portland (KRTX)

07 Apr  Base Reflectivity - Medford (KMAX)

07 Apr Base Reflectivity – Gray’s Harbor (KLGX)

07 Apr  Base Reflectivity - Seattle (KATX)

Here is Paul’s archived National Radar Composite from yesterday.  The southern portions of the Mississippi and Central Flyway have a curtain of weather keeping the trek north curtailed.  But behind the curtain there was widespread movement from Des Moines to Portland Maine.  Another jammin’ night across the Straits and our part of the party was in full swing from San Diego to Seattle.

And here are the weather maps (click on any image to bring up a full gallery view)

In the Vorticity plot you can see that nice big ridge of high pressure that has everybody in the PNW itching to put on their summer clothes.

04 Apr 2014 PNW Migration Update

Another cold front is moving in from the Pacific.  Lots of clouds and scattered precipitation.  In the loops we can see a wee bit of opportunistic migration but that’s about it.  It’s still early in the season and there are better days ahead.

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

04 Apr Base Reflectivity - Portland (KRTX)

04 Apr HC - Portland (KRTX)

Here is Paul’s archived National Radar Composite from yesterday.  The severe storms pounding the mid-west kept migrants restricted to the Gulf States last night.  The southern portion of the Pacific Flyway was quite active, and some of those birds are headed our way.

And here are the weather maps (click on any image to bring up a full gallery view)

Next update will be on Monday the 7th.

03 Apr 2014 PNW Migration Update

Very quick post –

Light north winds like last night (LaPuma correction) winds were out of the SSW and the birds were jammin’!  20+ dBZ most of the night.

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

03 Apr Base Reflectivity - Portland (KRTX)

03 Apr Base Reflectivity – Gray’s Harbor (KLGX)

03 Apr  Base Reflectivity - Seattle (KATX)

Here is Paul’s archived National Radar Composite from yesterday.

And here are the weather maps (click on any image to bring up a full gallery view)

02 Apr 2014 PNW Migration Update

The small ridge of high pressure has eased inland over night and has pushed the weather east.  The north winds are light and not forceful enough to keep the migrants grounded.  Looking at the loops from last night we see the west counties loaded up while the east counties were dealing with the remnant low.

The coast and the I5 corridor to our north also had significant migrant turnover so those loops are included in today’s update.  Yellowthroats, Orange-crown Warblers, and shorebirds are all popping up on the listserves.  As well as the usual overly optimistic sightings of Swainson’s Thrushes.  Sigh.

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

02 Apr Base Reflectivity - Portland (KRTX)

02 Apr Base Velocity - Portland (KRTX)

31 Mar HC - Portland (KRTX)

02 Apr Base Reflectivity – Gray’s Harbor (KLGX)

02 Apr  Base Reflectivity - Seattle (KATX)

Here is Paul’s archived National Radar Composite from yesterday.  The Atlantic Flyway has it’s first significant widespread migration event last night.  Cuban birds jumped the Straits, and the Gulf Coast was lit up again.  Good stuff!

And here are the weather maps (click on any image to bring up a full gallery view)

01 Apr 2014 PNW Migration Upate

In spite of the weather the birds were able to find a window early in the evening to get a bit further north.  When looking at the Reflectivity loop from last night shortly after sunset (03:00 UTC – 20:00 PDT) you will see a flight up the I5 corridor.  The localized nature of these storm cells is allowing for some opportunistic advances north, and the SSE winds are aiding in those efforts.

There is a ridge of high pressure behind this current system which may dry things out but will also be bringing winds out of the north.  For the migrants its all about timing.

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

31 Mar Base Reflectivity - Portland (KRTX)

31 Mar Base Velocity - Portland (KRTX)

Here is Paul’s archived National Radar Composite from yesterday.  Widespread migration along the Gulf Coast, up into the Ohio Valley, and along the western flanks of the Appalachians, but shut down most everywhere else.

And here are the weather maps (click on any image to bring up a full gallery view)

31 Mar 2014 PNW Migration Update

Saturday and Sunday saw light and opportunistic migration.  Some, here and there between the rain cells that moved through.

But last night it was a different story.  Great conditions, south winds and only minor rain, had the radars lit up across the PNW.

A new low system is spinning up out in the Pacific dragging cold air out of the Gulf of Alaska.  It might slow things down for tomorrow.  It depends on when we get to the back side and the north winds that follow it.

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

31 Mar Base Reflectivity - Portland (KRTX)

31 Mar Base Velocity - Portland (KRTX)

31 Mar HC - Portland (KRTX)

31 Mar Base Reflectivity – Gray’s Harbor (KLGX)

31 Mar Base Reflectivity - Seattle (KATX)

Here is Paul’s archived National Radar Composite from yesterday.  While the Atlantic Flyway was shut down  the Mississippi Flyway was lit up from Brownsville to Green Bay!

And here are the weather maps (click on any image to bring up a full gallery view)

28 Mar 2014 PNW Migration Update

The birds found a window from sundown until around 1:00 am, where there was mainly an exodus from the Portland area and up the I5 corridor.  Then some significant weather moved in and it looks like they put down for the rest of the evening.

Winds will remain out of the south as a new low moves in.  But this one is much more organized and may have some heavy precipitation in it’s bowels, and with few breaks.

For those that are new to reading the radar loops: As you look at last night’s loops right around 02:30 Zulu (UTC) you will note a strong radial signal coming from the west of the radar.  That is the sun going down and is termed a “sun strobe”.  If you see one coming out of the east, that is sunrise.  Anyway, under normal circumstances in the PNW the birds take flight shortly after sundown and you can see the migrant bloom.

Since World War II, birds, bats, and bugs – the biodetections that appeared on military radar and subsequently on weather radar-have been considered a nuisance to be filtered out. Because they appeared at night and disappeared at dawn and were wispy and ethereal the detections of migrating birds on radar were termed “angels” by early radar technicians.  Angels indeed.

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

28 Mar Base Reflectivity - Portland (KRTX)

28 Mar Base Velocity - Portland (KRTX)

28 Mar HC - Portland (KRTX)

And because it is always a treat to watch the flight over the straits of Florida here is the Reflectivity loop from Key West last night:  It’s a long loop so wait for the sun strobe and then … boom!  Birds!

28 Mar Base Reflectivity – Key West (KBYX)

Here is Paul’s archived National Radar Composite from yesterday. We see the first significant movement along the SE Atlantic states, and some massive movement into Texas and up the Central Flyway.

And here are the weather maps (click on any image to bring up a full gallery view).

I will again be taking the weekend off from the updates, but i will check the radar and save any loops that show significant movement and get them posted on Monday.

27 Mar 2014 PNW Migration Update

Until this highly unstable series of pressure differentials passes it’s going to be tough on the birds to get any traction north and tough on us to see through the goop if they do.

Stay tuned and i’ll put something up when there are discernible radar returns of migration events.

26 Mar 2014 PNW Migration Update

At least a few adventurous birds continued north last night and maybe more than a few.  However the radar was swamped with returns from the storm cells so it is hard to get a handle on the exact magnitude.

It looks like we have a series of low pressure cells headed our way with some breaks in between.  Probably play out over the next 3 to 5 days and timing will be influencing migration, but i don’t expect any major movement in these unstable conditions.

Only one image today as there’s not much to see.
Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

29 Mar Base Reflectivity - Portland (KRTX)

Here is Paul’s archived National Radar Composite from yesterday.  Not much going on.  A decent flight from Oklahoma to Nebraska.

And here are the weather maps (click on any image to bring up a full gallery view)

25 Mar 2014 PNW Migration Update

As forecast, the low pressure trough is moving into the Pacific Northwest.  Ahead of it are the south winds and the migrants took advantage of the free mileage.  The advancing cloud cover obscured the western part of the flight but the HC scan tells the story.  Another night of heavy migration in the main, reaching 20+ dBX returns.

San Diego and Central Valley listservs are lit up with FOS reports and the consensus is that migrants alongn the Pacific Flyway are a bit ahead of schedule this year.  As David says, “look busy, birds are coming!”

Pacific Northwest Radar: (Click on the links below to open the .gif files in a new window)

25 Mar Base Reflectivity - Portland (KRTX)

25 Mar Base Velocity - Portland (KRTX)

25 Mar HC - Portland (KRTX)

Here is Paul’s archived National Radar Composite from yesterday. A few pockets of activity here and there in the Gulf States.  But again the real action is out here in the west.  From Yuma to Seattle birds are on the move.  Check out the Wind Map

And here are the weather maps (click on any image to bring up a full gallery view)