FVXX21 KWBC 210100 VOLCANIC ASH ADVISORY STATEMENT ISSUED 0100 UTC 21 APR 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-467 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE...INFRARED AND MULTISPECTRAL IMAGERY. UPPER WIND FORECAST FROM THE AVN MODEL. THE GEOPHYSICAL INSTITUTE IN QUITO. . ERUPTION DETAILS: OCCASIONAL ASH EMISSIONS. . DETAILS OF ASH: GOES-8 IMAGERY THROUGH 2345 UTC CONTINUES TO SHOW LOW AND MID LEVEL CLOUDS OVER THE AREA MAKING ASH DETECTION DIFFICULT. TUNGURAHUA REMAINS IN A VERY ACTIVE STATE AND COULD PRODUCE AN ASH EMISSION AT ANYTIME. THE GEOPHYSICAL INSTITUTE REPORTS THAT SEISMICITY IN THE VOLCANO HAS BEEN LOW. GOES-8 WILL BE IN RAPID SCAN MODE UNTIL 21/0326 UTC. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST ANY ASH UP TO FL300 WOULD MOVE WEST SOUTHWEST AT 15 TO 20 KNOTS. . THE NEXT STATEMENT WILL BE ISSUED BY 21/0700 UTC. . REAL TIME SATELLITE IMAGERY ALONG WITH THIS AND OTHER VOLCANIC ASH ADVISORY STATEMENTS OFTEN ACCOMPANIED BY A MAP DEPICTING ASH LOCATION ARE AVAILABLE AT INTERNET URL ADDRESS http://www.ssd.noaa.gov/VAAC/washington.html (all lower case except /VAAC/) . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . KARST . NNNN