Anchorage Center Weather Service Unit (ZAN)

The Anchorage Center Weather Service Unit (ZAN CWSU) is located in the Federal Aviation Administration (FAA) Air Route Traffic Control Center (ARTCC) in Anchorage, Alaska. The CWSU is staffed by four National Weather Service (NWS) meteorologists. Our hours of operation are from 5:00 am-9:00 pm daily.

ZAN is one of 21 ARTCCs in the United States and has an area of responsibility encompassing 2.4 square million miles starting at the north pole and bordering Russian, Japanese, Canadian, and Oakland Flight Information Regions (FIR).

Ted Stevens Anchorage International Airport is the main HUB airport in Alaska. In 2005, the Anchorage Airport was ranked 3rd worldwide for cargo throughput and 1st in the United States for cargo poundage. Each year, 5.9 billion pounds of cargo pass through Anchorage and 90% of all cargo sent from China to the U.S. goes through Anchorage first.

Over 100 active volcanoes in Alaska; and Kamchatka and Kuriles, Russia have the potential to seriously disrupt flight operations in and around the Alaskan FIR. Recent volcanic ash eruptions, from Augustine in 2006 and Kasatochi in 2008, interrupted flight operations into Anchorage Airport and resulted in numerous flight cancellations.

The Anchorage CWSU supports Air Traffic Managers at the Anchorage Center through verbal briefings and written warnings. Verbal briefings are given to individual controllers at the ARTCC and tower control facilities around the ZAN airspace, as well as to equipment technicians when weather conditions dictate. Two types of written products are also provided by the CWSU meteorologists. The Meteorological Impact Statement (MIS) is a 4 to 12 hour planning forecast of weather conditions expected to impact the ZAN air traffic. The Center Weather Advisory (CWA) is a short-term warning of hazardous weather conditions provided to all aviation interests, including private pilots, towers, flight service stations, and commercial airlines. Thus, a CWA is similar to but more localized than Airmets and Sigmets issued by the Alaska Aviation Weather Unit (AAWU).

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