May 2nd, 2014

Migration tonight

Now tonight, we have a little bit more to talk about. As predicted, the winds throughout the state have taken on a much more southerly origin with the incoming presence of a Low Pressure system, now oozing its way from Minnesota into Wisconsin (see surface analysis). This is just the tailwind that migrants were waiting for. Unfortunately, it is also bringing precipitation and low cloud cover into the northern third of the state, so migration is more spotty there as birds avoid dangerous conditions aloft. Let's take a look at tonight, and the next couple days by each third of the state:

Northern Illinois:
Tonight, due to the aforementioned storm systems and precipitation, we're not seeing as much movement as we could. Storms break up what would be the even distribution of migration throughout this third of the state, so areas host to storm activity during peak migration time (somewhere between 11ish and 3ish) will probably not see as much influx tomorrow. Looking at the radar (NW IL, NE IL), birds definitely are still moving where they can in light to moderate concentrations (between 50 and 200 individual birds moving per cubic kilometer of the sky). They're nervous, but they're still moving. Looking ahead at the wind forecast, it appears that tonight's favorable conditions will be short-

Winds tonight. Notice the counterclockwise
swirling system near the top left. That's the
Low pressure system we saw above.

lived. By tomorrow morning, winds will again be westerly, and by Saturday night, they will take on an unfavorable northerly component forecast to last at least as long as the forecast goes (Sunday evening). So bird it up tomorrow! Tonight will probably result in the weekend's best movements.

Central Illinois:
This one's going to be a little shorter because Central Illinois is basically in the same boat tonight as Northern Illinois. Precipitations is moving through Central IL tonight, but is much less concentrated. For that reason, migrants are still a little nervous, but influxes should be more evenly distributed around the region tomorrow morning. Looking at the radar, migration is light to moderate tonight, and is certainly a bit heavier than the average migration in Northern Illinois. As in Northern Illinois, however, tonight's favorable conditions will be short-lived. Expect westerly and then northerly winds developing tomorrow thanks to the passage of a cold front from the North. So like in Northern Illinois, bird it up tomorrow!

Southern Illinois:
This third of the state is experiencing the best conditions right now, with more powerful, uninterrupted southerly flow. This means that migrants are a-flyin', and the radar (SW IL, South-central IL, SE IL) doesn't lie. I'm tempted to call the movement there almost heavy, but it's on the upper end of moderate. With that, migration appears to be evenly distributed with the lack of precipitation, so tomorrow influxes of warblers, thrushes, vireos, sparrows, waterbirds, etc. should be readily visible throughout the

The point when winds in IL will split directions

region. Cool, eh? I wish I could bird around there tomorrow! Southern Illinois is also lucky in the wind forecast compared to the rest of the state, as it appears it may entirely avoid tomorrow's cold front and the associated northerly winds. Wind, especially in far southern Illinois, will take on a westerly origin tomorrow, but after that southerly winds are forecast to remain in place at least through Sunday evening. Sweet!

So which birds should you be looking for? See for yourself! Check out the fantastic, wonderful, lovable resource that is eBird.

All good? Good. Good luck everyone!