FVXX20 KWBC 231515 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1515 UTC 23 AUGUST 1999 BY THE WASHINGTON VAAC . SANTA MARIA 99-001 GUATEMALA 14.76N 91.55W . BACKGROUND: SANTA MARIA GUATEMALA (1402-03) SUMMIT HEIGHT 12375 FT (3772 M) . SOURCES OF INFORMATION: GOES-8 VISIBLE INFRARED AND MULTISPECTRAL SATELLITE IMAGERY. SURFACE REPORT RETALHULEU. . ERUPTION DETAILS: INITIAL ERUPTION TIME UNKNOWN. . DETAILS OF ASH CLOUD: A SURFACE REPORT WAS RECEIVED FROM RETALHULEU (MGRT) INDICATING AN ERUPTION OF SANTIAGUITO (PART OF THE SANTA MARIA VOLCANO). GOES-8 MULTISPECTRAL IMAGERY DOES SHOW A HOT SPOT OVER THE AREA SINCE ABOUT 1045 UTC WITH A MORE INTENSE HOT SPOT AT 1245 UTC. A SUSPICIOUS CLOUD WHICH MAY BE ASH CAN BE SEEN IN VISIBLE IMAGERY AT 1415 UTC SOUTH OF THE VOLCANO BUT DUE TO SIMILAR SCATTERED METEOROLOGICAL CLOUDS IN THE VICINITY WE CAN NOT CONFIRM AN ASH PLUME. . TRAJECTORY: ANY ASH BELOW FL180 SHOULD MOVE TO THE SOUTH TO SOUTHWEST AROUND 10 TO 15 KNOTS BASED ON MODEL GUESS WINDS ALOFT. . 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 LATEST SIGMETS. . THE NEXT MESSAGE WILL BE ISSUED BY 23/2100 UTC UNLESS ADDITIONAL INFORMATION BECOMES AVAILABLE. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN