Tom Stephenson leading the Thursday BBC walk tweeted out the mid morn report in the Midwood. I have no further details after that asking for more details exactly where. If you go, look for anybody brave enough to stand out in the rain.
or details here of Alie's checklist
http://ebird.org/ebird/view/checklist/S37132623
230 Update: I ran into friend Bob ONeill and he mentioned that two birders he talked to heard the Swainsons and saw it just minutes before. With this inclement weather, its a good bet the bird will stick thru the night. Same spot as usual , south Midwood along the middle asphalt path after first southern trail crossing (green shipping container 7)
