This weekend provided an excellent lesson in the futility of spring forecasting. Although forecasts were right on target in calling for wet, disturbed Gulf Coast weather throughout the weekend, the details weren’t quite as tidy as weather-watching birders might have hoped. Remember that one-two punch of cold fronts that were shaping up on Friday? That went awry as soon afterwards as Saturday afternoon, when the first front came to a screeching halt and planted itself across the Deep South. The second front came barreling into it early Sunday morning, and they joined forces to generate thunderstorms over a huge swath of the Southeast, before finally getting legs and moving out into the Gulf Sunday night. The national map remains a spidery tangle of fronts, with a fresh one – spawned by a Great Lakes-area low-pressure cell – moving in today and prolonging our unseasonable coolness.
What did all this mean for birding? Winds aloft never developed the strong easterly bias that had been predicted over the Gulf, so most coastal areas received arrivals, and persistently nasty weather meant fallouts were possible throughout the weekend – although the storms were patchy enough that many birds may have threaded the gaps and continued inland on the south-ish winds ahead of the stalled front. On Saturday, though TX and LA received the most birds, migrants were visible over the Gulf from every coastal station, from Brownsville all the way around to Key West:
Incoming flights on Sunday were much thinner, although a rather substantial arrival event could perhaps be seen along the MS/AL coast in mid-afternoon. The drop-off in traffic from Saturday to Sunday intrigues me, because wind conditions in Mexico appear to have been similar for departees; increasing cloud cover may have been the difference, cluing migrants in to distant trouble. Sunday’s animation:
Finally, arrivals on Monday seem to have been practically nonexistent (although it’s important to remember the possibility of migrants coming in below the radar beam, as they well might under adverse conditions). Fortunately, though, coastal areas had accumulated enough birds through the weekend to make for good birding. 15+ warbler species were reported from both Grand Isle and Fort Morgan on Monday. Yellow, Chestnut-sided, Magnolia, and Tennessee warblers seem to have been prominent constituents of this latest wave, as well as the transient spotted thrushes (Swainson’s, Gray-cheeked, and Veery); good numbers of tanagers, orioles, and grosbeaks continue to be reported as well.
Migration is currently on pause, but it will be the briefest of pauses: by tomorrow night, the southerlies will have re-exerted themselves, and the Yucatan Express will be rolling again. I highly recommend getting out before then if you can; grounded migrants in good diversity could be present just about anywhere in the Southeast.