A strong frontal boundary is currently moving east toward the Mississippi valley, having passed over the Texas coast and portions of Louisiana. This boundary is spawning strong storms and areas of precipitation (some of which is intense). Its passage coincided with a light migration of trans-Gulf migrants coming ashore (indicated by radar), at least along parts of the Texas and Louisiana coasts. Local migrant fallouts may have already occurred and may still be occurring. Depending on the degree to which winds after the frontal passage stay westerly and northerly, birds may remain in areas they have landed through tomorrow. Additionally, portions of the Mississippi Valley may see fallout conditions in the coming 24 hours, if this frontal boundary moves across areas where nocturnal migration is occurring. Furthermore, portions of NE Texas and areas just north and east of there may have had fallout conditions earlier today after last night’s movements.
John Arvin, a research associate at Gulf Coast Bird Observatory, posted the following message to TXBIRDS:
“The strong storm system and associated cold front has moved through Texas continuing what has been a most welcome wet winter and spring (so far) and is entering Louisiana at midday. The upper level wind measurements are made at 7:00 a.m. and at that hour all stations were showing very strong S to SE winds. Those no longer apply after frontal passage. No conspicuous bird migrants are visible on radar from Lake Charles westward. Although post frontal winds are not especially strong any migrants still trying to make shore will be flying too low for the radar to “see”. Ahead of the front bird targets are visible only east of Lake Charles (but not at New Orleans for some reason). I expect a light fallout this evening and tomorrow at most coastal woodlots as delayed migrants make it ashore.”
Some early trans-Gulf migrant passerines to watch for include Great Crested Flycatcher, Eastern Kingbird, Yellow-throated and early Red-eyed Vireos, Ovenbird, both waterthrushes, Prothonotary, Hooded, Worm-eating, Kentucky, and Swainson’s Warbler, Northern Parula, and Summer Tanager, among others.
If you live on the Gulf Coast, birding this evening or tomorrow morning is highly recommended, but be sure to be safe if the squalls are passing through your area and only go birding after they pass! Fallout or no, birding during tornados is a bad idea!
Posted 20 March 2012 by Andrew Farnsworth, Christopher Wood, Marshall Iliff, and Brian Sullivan of the Cornell Lab of Ornithology on behalf of Team eBird and BirdCast.