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2014 Pavlof Volcanic EruptionOverview:
The Alaska Aviation Weather Unit (AAWU) is the primary Meteorological Watch Office (WMO) for 2.4 million square miles of Alaska airspace, stretching from the North Pole to the North Pacific. The AAWU is responsible for AIRMETs, Area Forecasts, and SIGMETs for twenty-five zones across diverse climatic and topographic regions. AAWU forecasters also produce graphics to depict expected conditions for icing, turbulence, thunderstorms, and flight categories. One of AAWU’s unique aviation responsibilities is to identify and forecast the extent of cold air aloft (temperatures colder than -65°C) to support CWSU and FAA operations.

AAWU meteorologists forecast from the NWS Sand Lake complex near Ted Stevens International Airport. The AAWU is co-located with the NWS Weather Forecast Office (WFO) Anchorage, the Alaska Regional Operations Center, and the Alaska and Pacific River Forecast Center to maximize collaboration between NWS offices. AAWU forecasters also collaborate with Center Weather Service Unit (CWSU) Anchorage, the Aviation Weather Center, and international forecasts offices in Russia.

Volcanic Ash Center:
The AAWU doubles as the Anchorage Volcanic Ash Advisory Center (VAAC). The VAAC is responsible for detecting and tracking volcanic ash for more than fifty active volcanoes in Alaska. The VAAC also monitors volcanoes on the Kamchatka peninsula in Russia, watching for downstream impacts on the Anchorage Flight Information Region (FIR). The VAAC is tasked with domestic and international warning responsibilities which include issuing volcanic ash advisories and graphics. Meteorologists also monitor several inactive volcanoes for re-suspended volcanic ash threats. These tasks help fulfill obligations under the International Airways Volcano Watch program. The VAAC forecasters also coordinate with the United States Geological Survey (USGS) and international VAAC offices in Washington, D.C., Montreal, and Tokyo.

Forecast Challenges:
Alaska provides several challenging and unique opportunities for forecasters. Alaska’s vast and complex terrain is difficult to model due to extreme terrain interactions and extreme data sparsity. For example, surface observations do not exist for many critical mountain pass locations, and the majority of Alaska is not covered by weather radar. Aviation is considered the lifeline of Alaska as nearly 80% of communities are not on a road system. The result is a critical need for AAWU services to fill gaps in observational data to keep the lifeline of Alaska going.