FVXX21 KWBC 171330 VOLCANIC ASH ADVISORY ISSUED 1330 UTC 17 JUN 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-708 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE INFRARED AND MULTISPECTRAL IMAGERY. WIND FORECAST FROM AVIATION MODEL. . ERUPTION DETAILS: OCCASIONAL GAS AND ASH EMISSIONS. . DETAILS OF ASH: SATELLITE IMAGERY THROUGH 17/1245 UTC SHOWED EXTENSIVE WEATHER CLOUDS OVER THE VOLCANO MAKING ASH DETECTION DIFFICULT. IN THE SATELLITE IMAGES A PLUME OF POSSIBLE MIXED ASH AND CLOUDS WAS OBSERVED EXTENDING FROM THE SUMMIT TOWARD THE SOUTHWEST. HOWEVER IT IS NOT CERTAIN WHETHER ASH IS REALLY PRESENT IN THIS PLUME. IF ASH IS PRESENT IT IS BELIEVED TO BE BELOW FL260 BASED ON THE APPEARANCE OF THE POSSIBLE PLUME IN VISIBLE AND INFRARED IMAGERY. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH FROM THE SUMMIT TO FL260 WOULD MOVE TOWARD THE SOUTHWEST AT 15 TO 20 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 17/1930 UTC. . REAL TIME SATELLITE IMAGERY ALONG WITH THIS AND OTHER VOLCANIC ASH ADVISORIES 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/) . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN