FVXX21 KWBC 280515 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0515 UTC 28 NOV 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-177 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 MULTISPECTRAL AND INFRARED IMAGERY...REPORT FROM THE GEOFISICO INSTITUTO...WIND DATA FROM THE GEOFISICO INSTITUTO...VAFTAD...1800 UTC AVIATION MODEL WIND FORECAST . ERUPTION DETAILS: CONTINUOUS ASH AND GAS EMISSIONS . DETAILS OF ASH: THE INSTITUTO GEOFISICO REPORTS ALMOST CONTINUOUS ASH CONTAINING EMISSIONS REACHING AT LEAST 1 KM ABOVE THE SUMMIT AND ON ONE OCCASION AS MUCH AS 4 KM ABOVE THE SUMMIT. THIS WOULD MEAN ASH RANGES FROM FL200 TO FL300. NO ASH CAN BE SEEN IN SATELLITE IMAGERY THROUGH 0445 UTC. HOWEVER ASH DETECTION IN SATELLITE IMAGERY MIGHT BE HINDERED BY THE LOW LEVEL CLOUDS IN THE AREA. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH BETWEEN FL160 AND FL390 WILL MOVE TO THE SOUTHWEST AT 10 TO 25 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 28/1115 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN