So before the arrival of a cold front from Northwest of us into the Prairie State, birds are getting one more night with favorable, southerly winds. Birds in Central and Southern Illinois especially are moving with moderate to heavy concentrations right now, and that concentration will probably increase as the night progresses. Northern Illinois, on the other hand, is dominated by precipitation tonight, and probably will not see much movement. Let's take a look by region:
As said, Northern Illinois is currently occupied by large and energetic areas of storm activity thanks to the approach of a cold front. Winds in North-central and northwestern Illinois are much calmer than in the rest of the state (or even in northeastern Illinois), and this lack of a significant tailwind is the second blow to migration in Northern Illinois overall. So, it seems that tomorrow morning will come about without the arrival and influx of much but rain, though birds will probably be moving in some concentrations around the margins of the storms. So that's that. Moving on to what we'll be seeing in the next few days, winds are forecast to be thoroughly northwesterly by tomorrow afternoon. After that, the winds will become more due northerly and last in that form at least through Thursday. So again, we find ourselves in a migratory hiatus after tomorrow afternoon.
Mostly avoiding the precipitation in Northern Illinois, Central Illinois is a stage set for migration tonight. Movement is already moderate and will likely become heavy by later tonight. Winds remain to be southerly, and the birds are riding them. So get out there and find the migrants tomorrow while they're still moving! Tomorrow night, with the passage of a cold front, winds will become northerly and by extension unfavorable. According to the wind forecast, they'll be grounded like us primates at least through Thursday night.
As far as tonight has developed in Southern Illinois skies, Southern Illinois is currently host to the heaviest migration around the state (SW IL, S-central IL, SE IL). With strong and direct southerly winds, the birds are travelling northward from the Southern States. So tomorrow morning, expect some definite arrivals and influx. Like southern Illinois often does, it is luckier than the rest of the state with its wind forecast. The cold front and its northerly winds are forecast to take until late Thursday morning to overtake Southern Illinois, so Wednesday night should also see some movement in Southern Illinois is not anywhere else.
So that's that! Here's my secret weapon of bird migration prediction (eBird).
And with that, I bid you all adieu. Good birding!