FVXX21 KWBC 252340 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 2340 UTC 25 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-294 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...1200 UTC AVIATION MODEL WIND FORECAST...WIND DATA PROVIDED BY THE OBSERVATORY IN QUITO . ERUPTION DETAILS: EMISSIONS OF ASH AND STEAM . DETAILS OF ASH: SATELLITE IMAGERY THROUGH 2315 UTC DID NOT REVEAL ANY ASH THROUGH BROKEN MID AND HIGH LEVEL CLOUDS. . TRAJECTORY: NEITHER NUMERICAL MODELS NOR UPPER AIR DATA PROVIDED BY THE QUITO OBSERVATORY HAVE ACCURATELY PORTRAYED THE MOVEMENT OF ASH AS SEEN IN SATELLITE IMAGERY TODAY. THEREFORE NO TRAJECTORY WILL BE ATTEMPTED WITHOUT SATELLITE CONFIRMATION OF AN ASH CLOUD. . 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 26/0530 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . TURK . NNNN