Definition
A METAR weather code indicating that volcanic ash is present in the atmosphere at or near the reporting station. Volcanic ash consists of fine, abrasive particles of pulverized rock and glass ejected by an erupting volcano and carried by upper-level winds, sometimes for thousands of miles from the source.
Plain English
A weather report code that warns pilots there is ash from a volcano in the air around the airport.
Context Anchor
Seen in METAR airport weather reports when volcanic ash is observed at or near the reporting airport.
Derivation
The code 'VA' is taken from the first and last letters of 'Volcanic Ash' to keep METAR codes short and unambiguous in international weather reporting.
Why Pilots Care
Volcanic ash can clog engines, abrade windshields, and cause sudden loss of thrust or visibility.
Grounding Statement
Picture a gray-brown cloud of gritty volcanic dust crossing the airport area or flight path.
Intuition Check
Do not picture soft fireplace ash. In aviation, volcanic ash means hard, abrasive volcanic particles that can seriously damage an aircraft.
Example Sentence 1
The METAR included VA in the present weather group, so the crew rerouted around the affected airspace before departure.
Example Sentence 2
Dispatch issued a SIGMET for VA moving southeast at flight level 350.