Thursday, April 24, 2014

April 25-29: Update to Migration Forecast

A Nashville Warbler, one of the typical migrants of late April, peers out among the leaves, as if it were taking a cautious look at the ever-changing weather forecast. 
April 24, 2014: A few days ago, it looked as if tonight and tomorrow would have ideal weather conditions for a big push of migrants, so I predicted that Friday, the 25th, would be a big day. The large-scale weather pattern has changed a bit since then; a low-pressure system is still approaching, but the local setup won't be as good for depositing migrants on the Lake Erie shoreline.

Here's the way it looks right now. Tonight, Thursday night, large numbers of migrants should be moving in regions to the south of us. Just where they'll wind up Friday morning is hard to say -- especially with rain moving in from the west, which will put the birds down wherever they happen to be when it arrives. I suspect that most good stopover habitats in Ohio will see new migrants on Friday morning. This should include the lakeshore migrant traps, but numbers there may not be exceptional compared to inland sites. So, in between rain showers, Friday should produce good birding and some new migrants, but maybe not any huge numbers.

I spoke with Mark Shieldcastle, who has more experience than anyone in predicting the timing of migration in this region, and he more or less agreed with that assessment (with the caveat that the track of the approaching low could change over the next few hours, and change the outcome). Mark pointed out that the overall timing of species arrival at the BSBO main banding site is close to normal but that numbers have been low. A few species, such as Nashville and Palm warblers, have been surprisingly scarce so far.

See the previous post for a list of expected species at this time in April. In addition to those, Friday could have potential for the "overflight" species -- birds with more southerly ranges, overshooting their intended destinations and winding up here. These include Yellow-throated, Hooded, Kentucky, Worm-eating, and Prairie warblers, plus Louisiana Waterthrush. 

Looking beyond Friday, the next few days should see more migrants trickling in despite the lack of optimum winds. Big numbers of migrants are building up to the south of us, and some of them will move without waiting for perfect conditions. With the trees barely beginning to leaf out, viewing is good in northwest Ohio, especially close to Lake Erie, so it's worthwhile to get out and see the migrants any day if you get the chance!

Summary: Friday, the 25th, is likely to be the best day out of the next five for migrants arriving on the Lake Erie shoreline, but numbers may be only moderately good. Based on current weather predictions, I would say this: if you are debating whether to drive a long distance to bird at Magee Marsh on Friday, you might have better success by birding your own local spots instead, since migrants are likely to be widespread across the region. But I will try to post an update in the comments section sometime late Thursday night. 

1 comment:

mo pie said...

Thanks for the updates, Ken. I'm a California birder making my first trip to Magee Marsh in mid-May, so will be following the blog with interest. (And P.S. your book was excellent.)

Nature Blog Network