FVXX21 KWBC 120825 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0825 UTC 12 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-237 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...U.S. NUMERICAL MODEL WIND FORECASTS . ERUPTION DETAILS: CONTINUOUS EMISSION OF ASH AND STEAM WITH OCCASIONAL LARGER PUFFS . DETAILS OF ASH: A POSSIBLE ASH CLOUD WAS WITHIN A 10 KM (5 NMI) RADIUS OF 1.5S/78.9W AT 0745 UTC. MULTISPECTRAL IMAGERY SUGGESTED THE POSSIBILITY OF A SMALL ERUPTION AROUND 0615 UTC THAT PRODUCED THE CLOUD. THERE WAS NO OTHER EVIDENCE OF ASH IN SATELLITE IMAGERY. THE HEIGHT OF THE ASH CLOUD WAS ESTIMATED AT FL190. . TRAJECTORY: TOWARDS THE WEST AT 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 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 12/1430 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . TURK . NNNN