Last night southwest winds over much of the Mid-Atlantic triggered moderate levels of migration into the region while a stalling stationary front across northern New Jersey minimized any passage of birds out of the Garden State. Here’s the radar from sunset last night through 5:00am this morning.

Frames are every 1/2 hour. Click on the thumbnail to view the full-sized animation.

 

Before you get looking at the radar you might want to check out the current forecast map for the US here which will give you an idea of the front I refer to above and the associated precipitation still lingering to our north. If you click on the regional composite radar loop above you’ll also see how that line of precipitation pushes downstate through the middle of the night, and then begins to back off into the early morning hours. Just south of that precipitation line is the actual stationary front, north of which the winds are light northerly and south of which they’re from the southwest. While not exceptionally strong (birds can still migrate on a light headwind) they do appear to have blocked any major migration into northern NJ as far as the radar can tell.

Looking at the Fort DIX loop it appears that migration was heaviest in the southwestern quadrant suggesting that the bulk of migrants were still coming in from inland rather than from along the coast. This is pretty typical given that we haven’t had much of a coastal push as of yet. Also of interest is how most of the migration early in the night appears to be at high altitude- which is represented by the doughnut shape of the reflectivity. Targets farther out from the radar center represent birds at higher altitude since the radar beam rises as it radiates away from the radar station. What I’m seeing on the radar is a lack of targets nearer the station (at lower altitude) and most targets farther out especially to the west. As these birds descend during the morning hours I can see some of them being picked up closer to the radar center which is what you would expect as they drop in altitude, although the radar appears to switch modes by morning and there’s a lot of noise in the data ‘mucking things up’. The velocity image does indicate a strong WSW->ENE movement suggesting that these targets are indeed birds, but again even the velocity image gets mucked up towards the end of the loop.

Looking at the Dover feed (DOX) we see another typical migration signal with birds also heading in a strong WSW->ENE direction at speeds 10-15kts faster than the prevailing winds. Migration is again heaviest in the west, but birds can be seen crossing the Delaware Bay near Cape May Point as well as up towards the mouth of the Delaware River.

For this morning in the southern half of New Jersey expect new birds in most locations with additional breeders back on territory in Belleplain State Forest, and migrants at spring hotspots from the Delaware River to Cape May. This ‘broad brush’ is guided by the heavier migration to the west (favoring locations along the Delaware River) as well as the strong directional winds pushing birds to the coast. Further north expect the highest concentrations of new birds to be in Central New Jersey along the line where winds turned northerly overnight (and especially anywhere that precipitation fell after midnight). I’m not expecting too much at Sandy Hook given the light NE winds this morning and the fact that only a small number of birds could be seen entering Manhattan on the NY radar. Garret Mountain should be a good bet this morning given the recent buildup of birds there over the last few days, the density of migrants over the region last night, and the presence of the frontal boundary near this spring hotspot as of this morning.

Okay- now it’s time to get out and see some birds. Please come back and let us know what you saw… otherwise it’s just me up here waving my hands 😉
Good Birding,

David