Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Washington warned about a volcanic ash plume that rose up to estimated 21000 ft (6400 m) altitude or flight level 210 . The full report is as follows: FVXX24 at 06:57 UTC, 18/09/19 from KNES VA ADVISORY DTG: 20190918/0656Z VAAC: WASHINGTON VOLCANO: POPOCATEPETL 341090 PSN: N1901 W09837 AREA: MEXICO SUMMIT ELEV: 17802 FT [5426…