FVXX21 KWBC 040130 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0130 UTC 04 DEC 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-201 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 MULTISPECTRAL AND INFRARED IMAGERY. AVIATION MODEL WIND FORECAST. . ERUPTION DETAILS: LAST VISIBLE ASH PLUME 01 DECEMBER 1245 UTC. . DETAILS OF ASH: THE VOLCANO HAS SHIFTED INTO A RELATIVELY QUIET STAGE IN THE PAST SEVERAL DAYS. NO ASH CAN BE SEEN IN SATELLITE IMAGERY THROUGH 04/0045 UTC. HOWEVER...THE VOLCANO REMAINS IN AN UNSTABLE STATE AND COULD PRODUCE A MODERATE TO LARGE ERUPTION AT ANYTIME. . TRAJECTORY: N/A . 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 04/0730 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN