FVXX21 KWBC 210800 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0800 UTC 21 OCTOBER 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-012 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... GUAYAQUIL METEOROLOGICAL WATCH OFFICE...U.S. NATIONAL WEATHER SERVICE NUMERICAL WEATHER PREDICTION MODELS . ERUPTION DETAILS: PERIODIC MINIMAL TO MODERATE ERUPTIONS. . DETAILS OF ASH: ASH CAN NOT BE SEEN ON CURRENT GOES-8 SATELLITE IMAGERY THROUGH 21/0715 UTC. IN ADDITION A PILOT REPORT RECEIVED BY THE METEOROLOGICAL WATCH OFFICE ON THE EVENING OF OCTOBER 20 INDICATED THAT THERE WAS SOME ASH TO FL230 NEAR THE VOLCANO. . TRAJECTORY: NUMERICAL MODEL FORECASTS SUGGEST THAT ANY ASH AT THE SUMMIT UP TO A LEVEL OF FL230 WOULD MOVE SOUTHWEST AT 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. . THE NEXT MESSAGE WILL BE ISSUED BY 21/1400 UTC. . WALTER/SAB/NOAA/NESDIS . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN