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:
Base Reflectivity – RTX
Base Reflectivity – JAX
Yeah, those returns are pushing 40dbz, for a significant amount of the night — MILLIONS of birds on the move.
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.
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.
With the winds shifting on the shoulder of a weak high pressure system, a bit of the pent up migration urges were released last night. We had a fairly heavy passing last night — even a tiny touch up into the 30 dBZ zone (yellow). Nothing like Duluth a couple of days ago, but still pretty solid.
The radar was obscured by the weather last night. We could make out very low level movement between the cells but nothing to write about. I did hear a number of Swainson’s Thrush nocturnal flight calls the past couple of nights.
Up north in BC at the Tatlayoko banding station the first Fox and Golden-crowned Sparrows were banded and a flock of Greater White-fronted Geese were seen.
As DavidLaPuma would say, “look busy … birds are coming!”