The U.S. Embassy in Turkey has current information about safety, and it lists any travel advisories for citizens on its website. Depending on the current situation, the Embassy may recommend postponing travel to Turkey, avoiding certain areas or taking special precautions while in the country.
International travelers can get up-to-date information about conditions in Turkey, or any other destination country, by enrolling with the Smart Traveler Enrollment Program, known as STEP, explains the program's website. The program is a free service that helps U.S. Citizens and nationals register with the nearest embassy while they are abroad. In the case of a natural disaster or other event, the embassy knows how to contact the traveler to offer information and assistance. It can also help family and friends get in touch with the traveler if there is an emergency at home.
The U.S. Department of State's division of U.S. Passports and International Travel maintains a webpage with current information and requirements for travel in Turkey. This page also has information about any alerts or warnings or messages from the embassy. It is a good resource for day-to-day information about travel to a foreign country as well as information about any special security risks.