FVXX21 KWBC 182100 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 2100 UTC 18 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-264 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...18/1200 UTC AVIATION MODEL WIND FORECAST 00 UTC UPPER LEVEL REPORT FROM GEOPHYSICAL INSTITUTE. . ERUPTION DETAILS: CONTINUOUS EMISSIONS OF ASH AND STEAM. . DETAILS OF ASH: LATEST GOES-8 IMAGERY THRU 2015 UTC SHOWS OCCASIONAL PUFFS OF ASH CLOUDS MOVING TOWARD THE WEST-SOUTHWEST AT ABOUT 15 KNOTS. EXTENSIVE METEOROLOGICAL CLOUDS IN THE AREA MAKES EXACT LOCATION OF ASH DIFFICULT TO DISCERN. UPPER LEVEL WIND DATA WOULD PLACE THIS ASH AT ABOUT FL180. THE GEOPHYSICAL INSTITUTE REPORTED YESTERDAY THAT THERE WERE CONTINUOUS EMISSIONS OF ASH AND STEAM. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ASH AT FL180 WOULD MOVE TO THE WEST-SOUTHWEST AT 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 19/0300 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . SCHWARTZ/NOAA/NESDIS/SAB . NNNN