Volcanic Ashfall — Alaska Peninsula, Alaska

2023-09-25 · Alaska Peninsula, Alaska

Event narrative

Several reports were received of ashfall in the communities of False Pass, Cold Bay, Sand Point and King Cove. The most noteworthy report was a measurement of 1/16th inch of ashfall in False Pass, the closest community to the volcano. There were also reports of volcanic lightning and thunder from residents in False Pass. Trace ashfall was reported by pilots and residents in several other locations around the southern Alaska Peninsula, in some cases reported as rain mixed with ash.

Wider weather episode

Another major eruption, part of an eruptive sequence lasting several months at the Shishaldin Volcano, occurred, starting around 4 AM AKDT September 25th, continuing for several hours that morning. The ash column reached an estimated peak height of 45,000 feet; this plume was steered away from the volcano near False Pass towards the southeast by prevailing northwest flow at the time of the eruption. This brought the ash plume across several towns along the southern end of the Alaska Peninsula, where numerous reports indicated minor ashfall and suspended ash over the course of the morning. Reports included pilot and on the ground reports of ash and visible ash appearing on runways and other surfaces in places including False Pass, King Cove, Cold Bay and Sand Point. The most notable ash accumulation measured at 1/16th inch in parts of False Pass.

Source: NOAA Storm Events Database, event_id 1133675. Narrative written by the NWS forecast office that issued the report.