FVXX20 KWBC 131050 . VOLCANIC ASH ADVISORY STATEMENT ISSUED 1050 UTC 13 JAN 1999 BY THE WASHINGTON VAAC . SOUFRIERE HILLS 99-007 WEST INDIES 16.72N 62.18W . BACKGROUND: SOUFRIERE HILLS MONTSERRAT (1600-05) SUMMIT HEIGHT 3000 FT (915 M) . SOURCES OF INFORMATION: MONTSERRAT VOLCANO OBSERVATORY. . ERUPTION DETAILS: 2 ERUPTIONS OCCURRING AROUND 13/1035 UTC. . DETAILS OF ASH CLOUD: THE VOLCANO OBSERVATORY AT MONTSERRAT REPORTED 2 PYROCLASTIC FLOWS OCCURRING AROUND 1035 UTC. THEY REPORT AN ASH CLOUD UP TO BETWEEN FL150 AND FL200 MOVING WEST NORTHWEST. NO ASH CAN BE DETECTED AS OF YET IN SATELLITE IMAGERY. . TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH UP TO FL200 WOULD MOVE WEST NORTHWEST AT 10 TO 15 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 LATEST SIGMETS. . THE NEXT MESSAGE FOR THIS EVENT WILL BE ISSUED BY 13/1700 UNLESS ASH CAN BE DETECTED IN IMAGERY OR NEW INFORMATION IS RECEIVED. . PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS. . NNNN