Strong winds swept ash from the largest volcanic eruption of the 20th century into the atmosphere Tuesday, creating a haze over Alaska's Kodiak Island and prompting the National Weather Service to issue flight warnings for the area.
Powerful northwest winds funneled through the mountains at the Katmai Bay, sending ash around 4,000 feet into the sky southeast toward Kodiak.
Brian Hagenbuch, general meteorologist at the National Weather Service Anchorage office, was the first to spot the ash. “When the sun came up yesterday, I noticed it looked foggy on the Larson Bay camera,” one of many cameras set up by the FAA to monitor weather conditions. But as the sun continued to rise, he noted the fog looked smoggy and brown.
Around 10 a.m., Hagenbuch checked the visible satellite and found a “milky, dome-shaped plume.” He then double-checked on infra-red equipment that is used specifically to spot ash even through cloud cover, which verified his findings.
Having confirmed his suspicions, Hagenbuch put together a "Significant Meterological Event" warning, called a SIGMET, to alert pilots of the hazardous conditions in the area.
Hagenbuch says that very strong winds “from time to time” will stir up the ash from Novarupta.
The Novarupta volcanic eruption of June 6, 1912, occurred in what is now the Katmai National Park and Preserve. For three days, the volcano spewed 100 times more material than the Mount St. Helens eruption, shooting plumes 20 miles into the air and burying the valley downwind in over 500 feet of ash and volcanic rock. Four years later, when botanist Robert Griggs visited the valley, steam still poured from vents across the valley, prompting the crew to name it The Valley of Ten Thousand Smokes.
Hagenbuch will update, and possibly cancel, the SIGMET on the National Weather Service’s website Wednesday. Hagenbuch notes that there is “much less” ash in the air than Tuesday.
Read more about the Novarupta eruption here.