FVXX21 KWBC 181200 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1200 UTC 18 NOV 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-135 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY. UPPER-AIR DATA AND REPORTS FROM THE GEOFISICO INSTITUTO. . ERUPTION DETAILS: CONTINUOUS STEAM AND ASH EMISSIONS. . DETAILS OF ASH: GOES IMAGERY THROUGH 18/1115 UTC SHOWED BROKEN CLOUDINESS OVER THE AREA HINDERING ANY ASH DETECTION BY MULTISPECTRAL IMAGERY OVER THE PAST 6 HOURS. . TRAJECTORY: ANY ASH BELOW FL250 WILL MOVE SOUTHERLY AROUND 15 TO 20 KNOTS AND ASH BETWEEN FL300 AND FL3500 WILL MOVE SOUTHWEST AROUND 15 TO 20 KNOTS. . 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/) . OUTLOOK: SEE SIGMETS AND VAFTAD. . THE NEXT STATEMENT WILL BE ISSUED BY 18/17300 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN