(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
(2) Issued:	(20170807/1853Z)
(3) Volcano:	Bogoslof (VNUM #311300)
(4) Current Color Code:	RED
(5) Previous Color Code:	ORANGE
(6) Source:	Alaska Volcano Observatory
(7) Notice Number:
(8) Volcano Location:	N 53 deg 55 min W 168 deg 2 min
(9) Area:	Aleutians
(10) Summit Elevation:	492 ft (150 m)
(11) Volcanic Activity Summary:	A significant explosive eruption began at Bogoslof volcano at about 18:00 UTC (10:00 AKDT) on August 7 and is continuing. A pilot report at 18:45 UTC indicates that the ash cloud had reached 32,000 ft asl. Thus, AVO is raising the Aviation Color Code to RED and Alert level to WARNING for Bogoslof volcano. Winds are currently to the south. Seismic and infrasound data suggest that the ash emissions are continuing.
(12) Volcanic cloud height:	32,000 ft asl estimated by pilot report
(13) Other volcanic cloud information:	Cloud moving towards south
(14) Remarks:	The SIGMET warning message for aviation, issued by the National Weather Service Alaska Aviation Weather Unit, currently is in effect up to 32,000 ft above sea level. Status of the ash cloud forecast can be found at their website at http://aawu.arh.noaa.gov/ See http://www.weather.gov/afc/ for details about expected ash fallout.
(15) Contacts:	Michelle Coombs, Scientist-in-Charge, USGS mcoombs@usgs.gov (907) 786-7497 David Fee, Acting Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 322-4085
(16) Next Notice:

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AVO/USGS Volcanic Activity Notice

Volcano: Bogoslof (VNUM #311300)

Current Volcano Alert Level: WARNING
Previous Volcano Alert Level: WATCH

Current Aviation Color Code: RED
Previous Aviation Color Code: ORANGE

Issued: Monday, August 7, 2017, 10:53 AM AKDT
Source: Alaska Volcano Observatory
Notice Number:
Location: N 53 deg 55 min W 168 deg 2 min
Elevation: 492 ft (150 m)
Area: Aleutians

Volcanic Activity Summary: A significant explosive eruption began at Bogoslof volcano at about 18:00 UTC (10:00 AKDT) on August 7 and is continuing. A pilot report at 18:45 UTC indicates that the ash cloud had reached 32,000 ft asl. Thus, AVO is raising the Aviation Color Code to RED and Alert level to WARNING for Bogoslof volcano.

Winds are currently to the south. Seismic and infrasound data suggest that the ash emissions are continuing.

Recent Observations:
[Volcanic cloud height] 32,000 ft asl estimated by pilot report
[Other volcanic cloud information] Cloud moving towards south

Hazard Analysis:
[Ashfall] None expected OR Trace of ash fallout in Unalaska possible

Remarks: The SIGMET warning message for aviation, issued by the National Weather Service Alaska Aviation Weather Unit, currently is in effect up to 32,000 ft above sea level. Status of the ash cloud forecast can be found at their website at http://aawu.arh.noaa.gov/

See http://www.weather.gov/afc/ for details about expected ash fallout.

Contacts: Michelle Coombs, Scientist-in-Charge, USGS
mcoombs@usgs.gov (907) 786-7497

David Fee, Acting Coordinating Scientist, UAFGI
dfee1@alaska.edu (907) 322-4085

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

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