A towering eruption column rises from Crater Peak (hidden beneath weather clouds) and an eruption cloud (top left) spreads a short distance upwind (toward left in photo). The summit cone of Spurr is in sunlight left of the column. A light-tan cloud of ash (right of the column) is rising from pyroclastic flows sweeping down the east and southeast flanks of Crater Peak.

The eruption lasted about 3.5 hours and produced about 52 million m³ of volcanic ash. Westerly winds carried the ash eastward over Anchorage, across the Chugach Mountains and northern half of Prince William Sound. Up to 3 mm of sand-sized ash fell in Anchorage and coastal communities 1200 km downwind reported dustings of fine ash. Anchorage International Airport was closed for 20 hours because of the ash fall.