FVXX21 KWBC 231400 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1400 UTC 23 OCTOBER 1999 BY THE WASHINGTON VAAC . TUNGURAHUA 99-021 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 ...GEOPHYSICAL INSTITUTE...U.S. NATIONAL WEATHER SERVICE NUMERICAL WEATHER PREDICTION MODELS . ERUPTION DETAILS: CONTINUOUS VENTING OF ASH AND STEAM . DETAILS OF ASH: THROUGH 1315 UTC ANY ASH CLOUD IS OBSCURED BY THICK METEOROLOGICAL CLOUDS OVER THE COUNTRY. SURFACE OBSERVATIONS FROM SEGU AND SEQU AT 1252 UTC REPORT VOLCANIC ASH OVER THE VOLCANO BETWEEN FL220 AND FL330 MOVING WEST. THE GEOPHYSICAL INSTITUTE CONTINUES TO REPORT THAT SEISMIC ACTIVITY REMAINS HIGH AND IT IS LIKELY THAT THE VOLCANO CONTINUES TO VENT ASH AND GASES. . TRAJECTORY: NUMERICAL MODEL FORECASTS VALID AT 23/1200 UTC SUGGEST THAT ANY ASH BETWEEN FL220 AND FL330 WOULD MOVE TOWARD THE WEST TO SOUTHWEST AT 20 TO 30 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 AROUND 23/2000 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN