FVXX21 KWBC 101830 . VOLCANIC ASH ADVISORY ISSUED 1830 UTC 10 NOV 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-101 ECUADOR 1.47S 78.44W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 MULTISPECTRAL IMAGERY...GUAYAQUIL METEOROLOGICAL WATCH OFFICE SIGMETS...12 UTC AVIATION MODEL UPPER AIR DATA. . ERUPTION DETAILS: CONTINUOUS VENTING OF ASH AND STEAM NOW AT LOWER LEVELS. . DETAILS OF ASH: MULTISPECTRAL IMAGERY INDICATES THAT THERE CONTINUES TO BE A RELEASE OF ASH AND STEAM FROM THE SUMMIT. HOWEVER IT IS NOW BELIEVED TO BE NEAR-SUMMIT ACTIVITY WITH POSSIBLE ASH UP TO FL200. A SMALL AMOUNT OF ASH CAN BE SEEN NOW PUSHING TO THE SOUTHWEST OF THE SUMMIT AND THIS SUPPORTS THE FLIGHT LEVEL ASSESSMENT. CAUTION IS URGED THOUGH AS THE VOLCANO MAY ERUPT MORE VIGOROUSLY AT ANY TIME AND SEND ASH TO A MUCH HIGHER ALTITUDE AS WAS THE CASE EARLIER TODAY. THE HIGHER ASH EARLIER IS NO LONGER DETECTABLE. . TRAJECTORY: CURRENTLY SOUTHWEST AT 5 TO 10 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. . THE NEXT STATEMENT WILL BE ISSUED BY 11/0030. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . ORRISON . NNNN