As the latest cold front pushed east to the Atlantic, migration was heaviest right along the Eastern Seaboard. Southerly flow over the Florida Straits and Gulf of Mexico also brought a pulse of Caribbean, Trans-Gulf and Circum-Gulf migrants into the Lower 48 last night. Migration continued on the Left Coast as well, with heavy radar returns evident from the Desert Southwest, Great Basin, and Central Valley of California up through the Pacific Northwest. High pressure across the Great Plains and Midwest, however, kept most grounded over the region last night.