FVXX21 KWBC 121930 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1930 UTC 12 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-239 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...U.S. NUMERICAL MODEL WIND FORECASTS...WIND DATA FROM THE INSTITUTO GEOFISICO . ERUPTION DETAILS: CONTINUOUS EMISSION OF ASH AND STEAM WITH OCCASIONAL LARGER PUFFS . DETAILS OF ASH: DUE TO DENSE WEATHER CLOUDS IN THE AREA ASH CANNOT BE SEEN IN SATELLITE IMAGERY THROUGH 1845 UTC. EARLIER TODAY WHEN THE WEATHER CLOUDS WERE LESS DENSE AN ASH PLUME AT ABOUT FL200 WAS SEEN EXTENDING FORM THE SUMMIT TOWARD THE WEST NORTHWEST. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH BETWEEN FL180 AND FL250 WOULD MOVE TOWARDS THE WEST NORTHWEST AT ABOUT 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 AND VAFTAD. . 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 13/0130 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . STREETT . NNNN