|Blackburnian Warbler: Things are looking up for a big arrival of long-distance migrants like this on Tuesday or Wednesday of this week.|
As recently as 4 days ago, the weather forecast for this week hadn't looked promising. Today, Mark Shieldcastle pointed out to me that the forecast had changed in a major way. It now appears that we should get a major arrival of birds on either Tuesday April 29 or Wednesday April 30, or possibly both.
Here's the way it looks now. A big low-pressure system is moving in from the west. It will bring a lot of rain from Monday morning through Tuesday night. But sometime during the night, between Monday night and Tuesday morning, a warm front will move in, with rising temperatures and with winds going around to southerly. This will be part of a major weather system, with a good flow of air all the way from the Gulf Coast, so it should be bringing a lot of migrants from a long distance if they can find room to fly between the extensive rain showers.
Right now the prediction is for temperatures to reach 74 on Tuesday and 68 on Wednesday, with sustained south to southwest winds. Even with the rain, I'm sure there will be birds on the move. I don't know which day will be better. Even with lots of rain overnight, the warm front may bring a big push of birds Tuesday morning. Wednesday morning may be more of a sure thing. But there should be movement by diurnal (daytime) migrants both days.
After Wednesday, with the low-pressure center moving to the north of us, winds will be more westerly. Thursday and Friday may not produce a lot of new migrants from the south, but could bring some strays with a western flavor, such as American Avocet, Marbled Godwit, or Franklin's Gull.
If you're coming to the Magee Marsh / Ottawa NWR area for songbird migrants, don't neglect the nearby wetland habitats. Eurasian Wigeon was present with American Wigeons for the last two days at the impoundment visible from the observation platform at the corner of Krause and Stange roads, on the western edge of the refuge. (See the map at this link.)
Summary: A big arrival of migrants from the south is expected Tuesday April 29 and / or Wednesday April 30, along with a passing warm front, widespread rain, and southerly winds. One of these two days is likely to be the best one out of the next five, although many lingerers from this push should be around into next weekend.