FVXX21 KWBC 281900 VOLCANIC ASH ADVISORY STATEMENT ISSUED 1900 UTC 28 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-306 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. INSTITUTE GEOFISICO REPORT AND WIND DATA. . ERUPTION DETAILS: INTERMITTENT ASH AND STEAM EMISSIONS. . DETAILS OF ASH: THE FAINT PLUME SEEN EARLIER THIS MORNING IN IMAGERY IS NO LONGER DETECTABLE. THE INSTITUTE AND SURFACE REPORTS INDICATE THAT THE ASH EMISSION HAS DECREASED BUT ASH AND STEAM CONTINUES TO VENT INTERMITTENTLY NEAR SUMMIT. . TRAJECTORY: ANY ASH BELOW FL240 WILL MOVE TOWARDS THE SOUTH TO SOUTH SOUTHWEST AROUND 10 TO 15 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. . 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 29/0100 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN