I didn't want to reinstall everything because I have so many SDK versions installed and my development environment is set up just right. Getting it set up again takes way too long.
What worked for me was deleting, then re-creating the Android Virtual Device, being certain to put in a value for SD Card Size (I used 200 MiB).
while the above does fix the problem temporarily, it is recurring. I just tried my application within Android Studio and saw this in the output log which I did not notice before in Eclipse:
"/Applications/Android Studio.app/sdk/tools/emulator" -avd AVD_for_Nexus_S_by_Google -netspeed full -netdelay none
WARNING: Data partition already in use. Changes will not persist!
WARNING: SD Card image already in use: /Users/[user]/.android/avd/AVD_for_Nexus_S_by_Google.avd/sdcard.img
ko:Snapshot storage already in use: /Users/[user]/.android/avd/AVD_for_Nexus_S_by_Google.avd/snapshots.img
I suspect that changes to the log are not saving to the SD Card, so when LogCat tries to access the logs, they aren't there, causing the error message. The act of deleting the AVD and re-creating it removes the files, and the next launch is a fresh launch, allowing LogCat to access the virtual SD Card.