FVXX21 KWBC 202100 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 2100 UTC 20 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-272 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE...INFRARED...AND MULTISPECTRAL IMAGERY...20/1200 UTC AVIATION MODEL WIND FORECAST. . ERUPTION DETAILS: OCCASIONAL EMISSIONS OF ASH AND STEAM...SMALL EXPLOSION AT 1300 UTC. . DETAILS OF ASH: GOES-8 IMAGERY AT 1745 UTC SHOWED LOW LEVEL METEOROLOGICAL CLOUDS HINDERING THE DETECTION OF ASH. IMAGERY AFTER 1745 UTC IS UNAVAILABLE BECAUSE OF RSO. . TRAJECTORY: ASH FROM THE 1300 UTC ERUPTION MOVED SOUTHWARD. . 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 21/0300 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . BROWN . NNNN