FVXX21 KWBC 180900 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0900 UTC 18 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-262 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...18/0600 UTC AVIATION MODEL WIND FORECAST. . ERUPTION DETAILS: PERIODIC EMISSIONS OF ASH AND STEAM. . DETAILS OF ASH: LATEST GOES-8 IMAGERY THRU 0745UTC SHOWS NO SIGNS OF ASH AROUND THE VOLCANO. TUNGURAHUA REMAINS IN A RESTLESS STATE AND MAY ERUPT AT ANYTIME. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH AT OR BELOW FL300 TO MOVE NORTHWEST 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. . 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 18/1500 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . KARST/NOAA/NESDIS/SAB . NNNN