Weather Blog

Where would Mt. Redoubt's ash cloud go?

Where would Mt. Redoubt's ash cloud go?
Steam and gas rise from a large fumarole on the north flank of Alaska's Mount Redoubt in this January 2009 file photo.

After weeks on edge, Alaska's Mt. Redoubt volcano finally erupted. Likely the biggest impact will be from the volcano's ash cloud, which aside from coating areas north of Anchorage with some of the gritty dust, can also have a great impact on regional air travel.

Ash is abrasive and can damage sensitive mechanisms, so planes are kept far away from any ash clouds and could lead to regional flight cancellations or diversions. Air traffic in and out of southern Alaska could be affected for a while -- depending on how much longer the volcano erupts and the direction of the upper level winds.  Air traffic disruptions could be especially affected at night, when pilots can not visually see any ash plumes.

The odds of impacting air traffic around the Pacific Northwest are quite low. It would really have to be a mega eruption, plus the wind pattern would have to be just right to get any significant ash this far away, and even so, the ash would be much higher in the atmosphere, and likely well above normal air traffic. It could make for a hazy sky and some really red sunrises and sunsets, though.
But for those that want to track the volcano, here are some links to do just that:

The Alaska Volcano Observatory is the "home base" for the volcano. But one of the really cool links is their Puff ash cloud prediction page.

Here, if you select how high the initial ash cloud makes it, it'll show you a computer forecast model projection, using one of the weather models, as to where the ash cloud will go. The Sunday eruption made it up to 50,000 feet, so you want to use the highest level -- the 16km version.

This site also has some upper air wind trajectories.

In looking at the wider scale, while initially the ash plume was carried north, if the volcano were to erupt again, upper level winds are expected to veer and point almost straight from central Alaska down the Pacific Coast through the Pacific Northwest Tuesday and Wednesday. But by then, the ash is way up in the stratosphere and above any ground effects -- so it shouldn't affect local air traffic or bring any ash to the ground here. But if the skies clear a bit, it could make for some spectacular sunsets.