FVXX20 KWBC 222340 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 2340 UTC 22 MAR 1999 BY THE WASHINGTON VAAC . SOUFRIERE HILLS 99-057 WEST INDIES 16.72N 62.18W . BACKGROUND: SOUFRIERE HILLS MONTSERRAT (1600-05) SUMMIT HEIGHT 3000 FT (915 M) . SOURCES OF INFORMATION: GOES-8 INFRARED AND MULTISPECTRAL IMAGERY. MONTSERRAT VOLCANO OBSERVATORY. 1200 UTC GUADELOUPE SOUNDING. . ERUPTION DETAILS: ASH VENTING EVENT AROUND 22/2230 UTC. . DETAILS OF ASH CLOUD: THE VOLCANO OBSERVATORY CALLED WITH A REPORT OF ANOTHER EVENT AROUND 22/2230 UTC BUT BECAUSE OF CLOUD COVER THEY COULD NOT ESTIMATE THE HEIGHT OF THE ASH. SATELLITE IMAGERY THOUGH 22/2315 UTC HAS BE UNABLE TO DETECT ANY ASH FROM THIS EVENT. THERE ARE SOME THIN HIGH LEVEL CLOUDS MOVING EAST ACROSS THE AREA AND THESE WOULD MASK A LOW LEVEL ASH CLOUD BUT IF IT WAS A SIGNIFICANT EVENT TO SAY OVER FL200 THE MULTISPECTRAL IMAGERY WOULD MOST LIKELY DETECT THE ASH. THEREFOR WE ARE GOING TO ASSUME THE EVENT TO BE LIKE THE EARLIER EVENT TODAY AND BE BELOW FL100. WE WILL CONTINUE TO MONITOR THE AREA AND IF ASH IS DETECTED IN IMAGERY A UPDATE WILL BE ISSUED BEFORE THE NEXT STATEMENT IS DUE IN 6 HOURS. . TRAJECTORY: ASH BELOW FL100 WILL MOVE WEST TO NORTHWEST AROUND 15 TO 20 KNOTS. ASH BETWEEN FL180 AND FL300 WILL MOVE EAST AROUND 20 TO 50 KNOTS. . 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/messages.html (all lower case except /VAAC/) . OUTLOOK: SEE SIGMETS. . THE NEXT STATEMENT WILL BE ISSUED AROUND 23/0530. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN