 Hazardous Inflight Weather Advisory Service

Hazardous Inflight Weather Advisory Service (HIWAS) was a continuous broadcast of hazardous weather information which is transmitted over selected VORs.This hazardous weather includes AIRMETs, SIGMETs, Convective SIGMETs, Center Weather Advisories (CWAs), Severe Alert Weather Watches (AWWs), and urgent PIREPs.