 This study investigated surface waves generated by extra-tropical cyclones, ATCs. The authors found that ATCs generate waves that travel backwards relative to the cyclones movement, growing in size as they do so. They also discovered that the extended fetch concept, which applies to tropical cyclones, does not apply to ATCs. Instead, the concept of extended duration wave growth is more relevant. The authors concluded that their findings demonstrate that ATCs can produce waves that extend beyond the cyclones' lifetime. This article was authored by Vahid Cheshomziyahi, Vladimir Kudriyevsev, Maria Yurobskaya, and others.