When designers explain their early design ideas to others, they usually use face-to-face communication along with sketches. In practice, however, sometimes face-to-face meetings are not possible, and designers have to rely on asynchronous communication. Important contextual information that is available in face-to-face meetings often becomes missing in such asynchronous communications, which can lead to confusion and misunderstanding. To address this challenge, we present SketchComm: an enhanced tool to support rich and flexible asynchronous communication of early design ideas. The key of the system is to allow designers to capture and communicate important contextual information to the audience in addition to sketches. A user study with designers and audience demonstrated effectiveness of asynchronous early design communication using SketchComm.