Volcanic ash and METARs
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?