Forecast and Analysis

Regional Migration Analysis: 22-30 March 2013

Andrew Farnsworth The Cornell Lab Mar 29, 2013


Wilson’s Warbler was on the move in portions of the West and Gulf Coast and Southeast this past week. This bird was photographed by Brian Sullivan.


Scattered light movements began the period, particularly in the California and portions of the Desert Southwest. By the end of the weekend and beginning of the week, migration was more widespread in California with light to moderate movements and in scattered locations of light movements across a number of other western areas including the Northern Rockies and Desert Southwest. This pattern continued through the middle of the week. Birds on the move this week included, among others, Pacific-slope FlycatcherWarbling Vireo, Wilson’s Warbler and Scott’s Oriole.

Great Plains

Low pressure and precipitation shut down the system to begin the forecast period and the shut down continued through the middle of the week. High pressure built into the region, bringing cool temperatures and northerly flow, all but inhibiting most migrants aside from the locally light movements across the region. By the end of the period, more widespread light to locally moderate movements occurred in the central and southern Plains. Birds on the move this week included continuing movements of waterfowl, American White Pelican, continuing movements of early shorebirds like Greater Yellowlegs, and Ring-billed Gull.


High pressure dominates the scene over much of the East, with cool temperatures and northerly flow in many areas slowing migration to a trickle of incoming arrivals. The West, however, experienced several nights, this one included, of light to moderate movements and pulses of new spring arrivals. Although trans-Gulf movements have been largely non-existent this forecast period, circum-Gulf migration has brought a number of new arrivals in the US via Texas.

Upper Midwest and Northeast

Other than some widely scattered light movements over the weekend and early week, the passage of a strong early spring storm coupled with strong high pressure following it shut down most movements through the middle of the week. However, by the end of the week, light migration was apparent in many portions of the Mississippi River Valley, including some locally moderate movements. Birds on the move this week included, among others, Common Loon, Green-winged Teal, and Great Egret.

Gulf Coast and Southeast

A stalled front divided Texas into areas with light to moderate movement south of the boundary and virtually no movement north of the boundary. Some light to moderate movements occurred in the Southeast as well. However, by Saturday and Sunday night a strong system with lots of precipitation shut down movements in most locations away from northern Florida. As high pressure built in behind this system, migration shut down in most areas by midweek, when only portions of Texas continued to experience scattered light movements. By the end of the period, more favorable conditions prevailed for light movements to expand in a few other areas of the region, including Florida and portions of the Gulf Coast states. Birds on the move this week included, among others, Upland Sandpiper, Eastern Kingbird, and Black-throated Green Warbler.