FVXX20 KWBC 080730 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 0730 UTC 08 OCTOBER 1999 BY THE WASHINGTON VAAC . GUAGUA PICHINCHA 99-037 ECUADOR 0.17S 78.60W . BACKGROUND: GUAGUA PICHINCHA (1502-02) SUMMIT HEIGHT 15,695 FT (4784 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY THROUGH 0645 UTC. 0000 UTC NUMERICAL WEATHER MODEL AND TRAJECTORY FORECASTS. UNITED STATES GEOLOGICAL SURVEY AT GEOPHYSICAL INSTITUTE IN QUITO. . ERUPTION DETAILS: THE USGS AT THE GEOPHYSICAL INSTITUTE REPORTED AN EXPLOSIVE ERUPTION OF GUAGUA AT 07/1207 UTC. DETAILS OF ASH CLOUD: ASH CANNOT BE DISCERNED IN SATELLITE IMAGERY THROUGH 0645 UTC. SOME OF THE DIFFICULTY SEEING ASH MIGHT BE DUE TO THE PRESENCE OF METEOROLOGICAL CLOUDS. WESTWARD MOVING ASH FROM THIS ERUPTION HAD PREVIOUSLY BEEN ESTIMATED TO BE AT FL400 AND EASTWARDLY MOVING ASH WAS ESTIMATED AT FL500. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH AT ABOUT FL400 WOULD MOVE TOWARDS THE WEST-SOUTHWEST AT LESS THAN 15 KNOTS AND ASH AT ABOUT FL500 WOULD MOVE TOWARD THE EAST OR NORTHEAST AT 15 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 www.ssd.noaa.gov/VAAC/washington.html (all lower case except /VAAC/) . OUTLOOK: SEE SIGMETS AND VAFTAD. . THE NEXT MESSAGE WILL BE ISSUED BY 08/0730 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN