Ashfall advisory

An Ashfall advisory is a weather advisory issued by the National Weather Service of the United States. Ashfall advisories are issued when there is a likely future or present occurrence of ash rain caused by a large plume of suspended airborne ash, typically caused by large fires or volcanic activity. The National Weather service map color is Dark Grey.

Ashfall Advisories are often accompanied with special weather statements.

Example of an ashfall advisory
URGENT - MARINE WEATHER MESSAGE...CORRECTED National Weather Service Honolulu HI 708 AM HST Thu May 17 2018

...ASHFALL ADVISORY IN EFFECT...

Ash from Kilauea Volcano will affect waters east through south of the Big Island.

PHZ122-124-172200- /O.COR.PHFO.MH.Y.0001.180517T1700Z-180517T2200Z/ Big Island Windward Waters-Big Island Leeward Waters- Big Island Southeast Waters- 708 AM HST Thu May 17 2018

...ASHFALL ADVISORY IN EFFECT UNTIL NOON HST TODAY...

The National Weather Service in Honolulu has issued an Ashfall Advisory, which is in effect until noon HST today.

about 415 am HST. Additional eruptions may occur the rest of this morning.
 * ERUPTION...Kilauea Volcano Summit (19.4N 155.3W) occurred at

but especially downwind of Kilauea Volcano.
 * LOCATION...Volcanic ash is expected to affect waters adjacent to

afternoon. The advisory may need to be extended if volcanic ashfall persists.
 * TIMING...This advisory is in effect until 12 pm HST this

possible on vessels in the advisory area. Mariners should avoid this area until the ashfall subsides.
 * IMPACTS...Ash accumulation of less than one quarter inch is

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For more information on the current status of Kilauea Volcano, see https://volcanoes.usgs.gov/volcanoes/kilauea/status.html