FVXX21 KWBC 210900 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0900 UTC 21 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-274 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. . ERUPTION DETAILS: OCCASIONAL EMISSIONS OF ASH AND STEAM. . DETAILS OF ASH: ASH WAS NOT DETECTED ON SATELLITE IMAGERY THROUGH 21/0815 UTC. THERE IS HOWEVER AN OCCASIONAL HOT SPOT OBSERVED THROUGH PARTLY CLOUDY CONDITIONS AT THE SUMMIT. . TRAJECTORY: NO ASH IS CURRENTLY BEING DETECTED. . 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. . EFFECTIVE JANUARY 3 2000 AT 0000 UTC... ALL REFERENCES TO LATITUDE AND LONGITUDE IN VOLCANIC ASH ADVISORY STATEMENTS WILL BE IN DEGREES AND MINUTES OF A DEGREE. EXAMPLE: 16.70N 62.20W WILL BE 1642N6212W . THE NEXT STATEMENT WILL BE ISSUED BY 21/1500 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN