FVXX21 KWBC 181000 VOLCANIC ASH ADVISORY ISSUED 1000 UTC 18 JUL 2000 BY THE WASHINGTON VAAC . TUNGURAHUA 00-838 ECUADOR 0128S 7826W . BACKGROUND: TUNGURAHUA ECUADOR (1502-08) SUMMIT HEIGHT 16480 FT (5023 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY. 18/1200 UTC AVIATION MODEL WINDS FORECAST FROM THE 18/0000 UTC MODEL RUN. . ERUPTION DETAILS: GASES WITH OCCASIONAL ASH EMISSIONS. . DETAILS OF ASH: IMAGERY THROUGH 0915 UTC DOES NOT INDICATE THE PRESENCE OF ASH. PILOT AND SURFACE REPORTS FROM 6 HOURS EARLIER DID INDICATE ASH AT OR NEAR THE SUMMIT. PILOTS ARE REMINDED THAT TUNGURAHUA REMAINS IN A VERY ACTIVE STATE AND COULD PRODUCE ASH EMISSIONS AT ANYTIME. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST ANY ASH AT OR NEAR SUMMIT LEVEL TO MOVE SOUTHWEST AT 5 TO 10 KNOTS. . OUTLOOK: SEE SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 18/1600 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. . HUGHES . NNNN