Favorable conditions for light to moderate movements are pervasive in the West, while major movements in the East occur primarily over the weekend. Species on the move this week will include Brant, American Wigeon, Ring-necked Duck, Yellow-bellied Sapsucker, Hermit Thrush, Golden-crowned Kinglet, Ruby-crowned Kinglet, Yellow-rumped Warbler, Le Conte’s Sparrow, Swamp Sparrow, White-throated Sparrow, Harris’s Sparrow, White-crowned Sparrow, Golden-crowned Sparrow, Dark-eyed Junco, and Pine Siskin.
Arrows show wind speed and direction (arrow points in the direction to which wind is blowing) 100 m above ground level. Areas with southerly winds are colored red; northerly winds colored blue. Accumulated precipitation (in 6 hour intervals) is green, outlined by white. Broadly speaking, areas of the map in red will experience conditions that are favorable for migration, and areas where red and green (and red and blue) intersect and overlap may experience migrant concentrations and fallouts as migrants interact with precipitation.
Much of the region will experience favorable or marginal conditions for the duration of the period. Widespread light to moderate movements will occur in many areas. Mid to late week will see increasing pockets of unfavorable conditions in the Four Corners and portions of the Desert Southwest and southern Rockies, which will but a damper on movements in those areas. And furthermore, a substantial remnant of a tropical depression (Hurricane Simon) will skirt the region during this period, shutting down migration where it passes. Of course, the passage of this system will bring another chance for out of range waterbirds to portions of the Desert Southwest on Wednesday and Thursday. Species on the move this week will include Hermit Thrush, Ruby-crowned Kinglet, Golden-crowned Sparrow, Ring-necked Duck, Varied Thrush, Cackling Goose, Mew Gull, Northern Shrike, Horned Grebe, Dark-eyed Junco, Yellow-rumped Warbler, Fox Sparrow, American Wigeon, White-throated Sparrow, and Lesser Scaup
Widespread moderate to heavy, and even locally very heavy movements, kick off the weekend in favorable northerly flow. These movements will become increasingly restricted to the northern Plains by the beginning of the workweek, and generally remain that way for the duration of the period. The remnants of a tropical system pass through the region on Thursday before opening the door for more widespread moderate to heavy movements to grace the entire region to end the week. Species on the move this week will include Dark-eyed Junco, Le Conte’s Sparrow, Harris’s Sparrow, White-crowned Sparrow, Swamp Sparrow, White-throated Sparrow, Golden-crowned Kinglet, Song Sparrow, Sharp-shinned Hawk, Tundra Swan, Yellow-rumped Warbler, Eastern Meadowlark, Savannah Sparrow, American Tree Sparrow, and Sedge Wren
Upper Midwest and Northeast
Moderate, heavy and very heavy movements will occur west of the Appalachians to start the weekend, as a strong frontal boundary passes this mountain range and shuts down movements at the coast. Some areas of New England may see moderate movements in continued easterly and northeasterly winds. As the system passes, much of the region will experience moderate to heavy movements on Saturday, but quickly see these dissipate as more southerly flow returns post-frontal passage. It is not until Tuesday or Wednesday that the next disturbance comes through the region and spawns moderate to heavy flights in the Upper Midwest. But even this new system is not organized or strong enough to create widespread regional movements, which may need to wait until the following weekend’s frontal passage. Species on the move this week will include Dark-eyed Junco, White-crowned Sparrow, Pine Siskin, Hermit Thrush, Golden-crowned Kinglet, Brant, White-throated Sparrow, Fox Sparrow, Ruby-crowned Kinglet, Swamp Sparrow, Ruddy Duck, Rusty Blackbird, Yellow-rumped Warbler, American Tree Sparrow, and Purple Finch
Gulf Coast and Southeast
Moderate to very heavy flights will occur this weekend, first to the west of the Mississippi River valley on Friday night, then over much of the region away from Texas and southern Florida on Saturday night. These movements are associated with the passage of a frontal system, and after it passes, conditions deteriorate substantially for migrants for the rest of the week. Southerly flow and scattered precipitation take hold, and the first glimpses of major movements will not be seen until the end of the week in Texas. Species on the move this week will include Yellow-bellied Sapsucker, Swamp Sparrow, White-throated Sparrow, Yellow-rumped Warbler, Golden-crowned Kinglet, Ruby-crowned Kinglet, Marsh Wren, House Wren, Tree Swallow, Palm Warbler, Dunlin, Eastern Phoebe, Savannah Sparrow, Northern Flicker, and Brown Creeper