What is Zulu (Z), GMT, and UTC time?
A7. Meteorologists across the globe use the same standard for keeping time. This avoids confusion in coordinating weather data from numerous time zones around the world. The standard for timekeeping is called “Greenwich Mean Time” (GMT). GMT is the current local time in Greenwich (London), England, where the Prime Meridian is established (zero degrees longitude). Other names for GMT are UTC (Universal Coordinated Time) and Z Time (Zulu Time). Any of these terms (GMT, UTC, Z) are acceptable, and they all mean the same thing. Most U.S. meteorologists use the term Z-time. So when you see 12Z, that means it is 12 noon in Greenwich, England. 20Z means it is 8 pm there, and 00z means it is midnight there. Here in the Pacific Time Zone, you would subtract 7 hours to get Pacific Daylight Time (PDT) from mid-March to early November. During Standard Time (early November-mid March), you would subtract 8 hours to get Pacific Standard Time (PST).
