I seem to recall that there are special notations that can appear on METARs when there is volcanic ash in the air, but when I look at current METARs for airports closed because of volcanic ash, I can't see anything special (in fact, I seem to see CAVOK more than anything else).

Am I just remembering incorrectly? Or does ash have to actually be dusting the airport to get into the METAR? Or what?

VA is for volcanic ashes and I have been looking for that on METARs as well without finding any so far...

Newquay had them for a bit

Yes, take LGW/EGKK METARs, for example.

As I write, the current one (1550z) is giving CAVOK. I'm not surprised, because here on the North Downs I've yet to SEE any deposit on the ground, and have no means of detecting it in the local air. Presumably, the Met observer at Gatwick is similarly handicapped? Visibility, >10k, is presumably too good to justify a Haze report.

Normally, the only Met phenomenon that justifies the closure of an airfield is lying snow. in that case, the METAR has the remark: "SNOCLO". The latter is not an observation of the actual weather. In this case, Gatwick is closed (correct me if I'm wrong) because NATS has closed certain types of airspace, including that - from the surface upwards - at Gatwick. Again, not necessarily because of the current weather observed at the station.

Would it not make practical sense to annotate METARS with "VOLCLO", or equivalent, as a warning to young aviators?

Chris

In this scenario entire FIRs have been affected by VA and entire FIRs have been closed, so you can find met indications on FIRs SIGMETand closure information on notamsHope this helps.