FVXX20 KWBC 181315 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1305 UTC 18 JULY 1999 BY THE WASHINGTON VAAC . COLIMA 99-042 MEXICO 19.51N 103.62W . BACKGROUND: COLIMA MEXICO (1401-04) SUMMIT HEIGHT 13451 FT (4100 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY THROUGH 18/1245 UTC. VAFTAD. MEXICO CITY METEOROLOGICAL WATCH OFFICE SIGMET. 1200Z MANZANILLO RADIOSONDE. ERUPTION DETAILS: ERUPTION OCCURRED AT ABOUT 17/1742 UTC. . DETAILS OF ASH CLOUD: METEOROLOGICAL CLOUDS CONTINUE TO COVER THE AREA AROUND THE VOLCANO PREVENTING ASH DETECTION IN SATELLITE IMAGERY. THE MEXICO CITY MWO SIGMET INDICATES ASH TO FL350 EXTENDING TO THE SOUTHWEST OF THE VOLCANO. THE VAFTAD INDICATES THAT THE LIKELY LOCATION OF ANY ASH IS TO THE WEST OF THE VOLCANO WITH LOWER AND MID LEVEL ASH TO THE WEST AND SOUTHWEST AND HIGH LEVEL ASH TO THE WEST NORTHWEST. THE VAFTAD INDICATES THAT THE AREA OF ASH MIGHT NOW EXTEND FROM THE VOLCANO TO THE WEST COAST OF MEXICO AND THEN CONTINUE FOR ABOUT 125 NMI (232 KM) OVER THE PACIFIC OCEAN. ALL ASH IN THE VAFTAD DEPICTION IS BETWEEN 17N AND 21N. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT MOST ASH WOULD MOVE TO THE WEST OR SOUTHWEST. ANY ASH THAT MIGHT BE PRESENT ABOVE ABOUT FL350 WOULD MOVE TO THE WEST AND WEST NORTHWEST. ASH SPEED WOULD BE LESS THAN 20 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 LATEST SIGMETS AND VAFTAD. . THE NEXT STATEMENT WILL BE ISSUED BY 18/1915 UTC. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN