09 October 2013 Migration Report

As the low passes through, the ridge continues to build in behind pushing the winds out of the north and bringing a flood of migrants.  It was one of those signature nights the migrants wait for.  Streaming across the Strait, torrents of birds along the coast, and a deluge down the I5 corridor.  We are dripping with birds tonight!

Here is the local KRTX Reflectivity loop.
Here is the Regional loop
Here is the Seattle KATX loop.
Here’s Paul’s National Composite

This weather looks to hold for the next 48 to 72 hours.  It may get cold but the winds aloft will continue out of the north and the skies should  be clear — perfect fall conditions for the trip south.

Here is the 850mb winds loop.
Here is the Vorticity Forecast

A reminder about these links:  The regional level loops will break in a few days, NCAR does not archive the images past that.  Paul’s loop will remain in perpetuity — he’s like that.  The forecast links are dynamic and constantly updated.  That is; if you go to past posts and follow those links, they will look just like today’s link.

BONUS!!  Left click and open the links below for full animated .gifs of the THREE regional Reflectivity Loops.  Yes, THREE.  Whereas NCAR does not archive the Langley Hill radar College of DuPage does. Not only that, but that is where the .gif downloads are from.  Sweet, sweet, sweet!

RTX Looped Reflectivity

ATX Looped Reflectivity

LGX Looped Reflectivity

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08 October 2013 Migration Report

Weak flight along the I5 corridor, nothing coming across the Strait, and only significant movement is around Gray’s Harbor.

We have a ridge that could build 36 to 48 hours out.  But until then — more of the same.

Regional Reflectivity Composite
Vorticity forecast.

07 October Migration Report

I spent the weekend in the field, hence no weekend updates.

However, even with the great conditions migration levels were moderate with a few heavy pulses at best.  I put peak radar returns in today’s gallery.

It looks like we’re winding this season down.  Surely the neo-trops are long gone and we are now just waiting on the winter residents to complete the season.  I usually wait for the first Bufflehead to show up before i close the fall season.  But: another couple of days with a low trough draped over the region, only a hint of a ridge 48 hrs out, and modest returns over the weekend with ideal conditions — i’m closing this season early.  I will continue to review the radar and if anything noteworthy pops up i’ll put that up.

But barring that — that’s all folks!  Circumstances allowing, i’ll be back in the spring.  Hopefully with a fix for the lost animated radar loops.

KRTX Reflectivity loop
Regional loop.
Paul’s National loop.
Vorticity forecast

04 October 2013 Migration Report

Yep — birds are on the move, in droves!

As forecasted the ridge moved in and winds are out of the north.  Clear skies for most of the evening.  We had heavy migration throughout the region.  From Vancouver Island to Eugene the skies were jammed with birds.

Here’s the KRTX Reflectivity loop
Here’s the Velocity
Here’s the Regional Composite
Here’s Seattle’s KATX
Here is Paul’s National Composite

Looks like we have 36 to 60 hours of this ridge before it starts to break down and be replaced.  That far out, it’s tough to tell what will replace it, but it looks like another low will be dipping down out of the Gulf of Alaska – we’ll see.  But until then, the next couple of days should be marvelous migrating and birding conditions.  Here comes our ducks (real ones that don’t have swooshes plastered all over them)!

Here is the Vorticity forecast.
Here is the 850mb winds loop.

03 October 2013 Migration Report

A better flight than i expected last night.  Upper level winds were favorable and there was enough room between the storm cells for moderate levels of migration to take place.  To our north the migration was even heavy at times.  The Puget Sound was filled with birds as was the Washington coast.  Too bad it’s only Thursday as some of us have to work.  The next few days should be really great birding.

Here is the local KRTX Reflectivity loop.
Here is the local KRTX Velocity loop.
Here is the Regional Reflectivity Composite.
Here is Paul’s archived National Composite

The forecast remains the same with a really nice ridge of high pressure building in behind this last little bit of the plague of a low we’ve been dealing with.

Here’s the 72 hr. vorticity forecast
Here’s the 84 hr. winds aloft forecast.

A note on these links:  The regional level loops will break in a few days, NCAR does not archive the images past that.  Paul’s loop will remain in perpetuity — he’s like that.  The forecast links are dynamic and constantly updated.  That is; if you go to past posts and follow those links, they will look just like today’s link.  It sucks for archival information, but until i can recode my scripts it’s the best i can do for now.  I’ve poked around and it looks like Python might be another avenue.  I’ll see what i can do between seasons to hack around in yet another programming language.

02 October 2013 Migration Report

With the winds easing up, but still out of the south, and the skies clearing, we had a moderate amount of birds in the air last night.  Surface winds are not as influential as the winds aloft on migrating birds, and those winds are actually out of the north as this weak ridge advances.

Here’s the local KRTX Reflectivity loop.
Here’s the Velocity loop.

There were more pockets of squalls up north but the birds kind of worked around them.  Small flights can be seen around Gray’s Harbor and the jump across the Strait and down 101 is again discernible.

Here’s the Regional loop.

It looks like we have one more low to get through before we get better conditions – maybe 48 hours out or so.  I suspect the flight tonight will be a bit subdued but Thursday and Friday  could be quite significant – depends on how many birds are left in the pipeline.

Here’s the Vorticity forecast
Here’s the 850mb wind forecast loop

01 October 2013 Migration Report

After being bottled up for a few days a moderate amount of birds picked their way through the squalls even if it was into a head wind.  Probably strong fliers like geese and ducks.  It is hard to see in a static image so you’ll have to watch the loops carefully to see the flight.

KRTX Base Reflectivity
KRTX Base Velocity

There was an early flight along the Washington coast and a late flight across the Strait and down the Hood Canal as well.  Again a static image just wont do because there is still a lot of rain in the region. So, check out the regional composite and watch closely.

Regional Composite.

Looking a the NAM 500mb Geopotential forecast my analysis is that we may get a bit of a ridge 24 to 36 hours out.  The wind and the rains will subside a bit but it will be followed by another strong low.  It’s not until about 72 hours out that we’ll see a return of some sustained northerly winds and optimal migrating conditions.  Here’s a loop of the 84 hr forecast for the Winds Aloft at 850mb Heights.