Volcanic Ashfall — Alaska Peninsula, Alaska

2023-07-22 to 2023-07-23 · Alaska Peninsula, Alaska

Event narrative

A small boat traveling from Dillingham to False Pass reported on Twitter that they were 25 NM from entering false pass, and just noticed some coarse ash on a tote lid. No additional reports of ashfall were recorded right in the community of False Pass. However, it's likely trace to minor ashfall occurred immediately to the north given satellite observations and ashfall model estimates provided by the Alaska Volcano Observatory based on the quantity and trajectory of ash emitted from the volcano.

Wider weather episode

The Shishaldin volcano, located near the center of Unimak Island in the far eastern Aleutians, entered an active/eruptive phase during mid to late July, with multiple lava flows and plumes of ash released intermittently for several days. At around 11 PM on 7/22, a powerful eruptive ash plume was observed on satellite up to 40,000 ft above sea level along with volcanic lightning, with weak westerly winds moving ash towards the community of False Pass. A small boat entering False Pass from the north during or shortly after the eruption on the early morning hours of 7/23 reported on social media that they had a light coating of ash on their vessel.

Source: NOAA Storm Events Database, event_id 1105289. Narrative written by the NWS forecast office that issued the report.