Local conditions proved to be conducive to northbound travel. Only some small scattered showers and mainly in and along the Cascades. Night flight can be seen taking off and leaving the area through the night. Replacement birds are of a lesser magnitude but still present. Also these birds are concentrated in west county along the coastal foothills. Looking at the velocity plot you can see the arriving birds concentrated from McMinnville to Hillsboro and very little east of the Willamette.
This flight was aided by the advancing low pressure off the coast of BC, and as long as we just get the southerly flows, and not precipitation, this will trigger more birds to take flight. It is April after all and the further we get into the season the stronger the impulse to move north.
As far as the pipeline to our south is concerned. Medford was dead last night. So dead in fact, that neither the Regional or National composite picked up any targets. I put in a local KMAX plot to show a more refined picture of — well, nothing, just a bunch of ground clutter. Further south only the central valley had conditions allowing widespread migration. There was also a very small movement in Orange County – mainly along the coast.
Nationally the same scenario is playing out; birds are on the move – weather permitting. A large frontal system is halting migration from the mid-Atlantic arcing back to Lake Michigan. The central and Mississippi flyways are lit up, and heavily, from Brownsville to Minot. The Southeast is seeing good flights up to the Virgina boarder and the gulf states continue to rock.