FVXX21 KWBC 041430
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VOLCANIC ASH ADVISORY STATEMENT
ISSUED 1430 UTC 04 APR 1999 BY THE WASHINGTON VAAC
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POPOCATEPETL 99-061    MEXICO  19.02N 98.62W
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BACKGROUND:    POPOCATEPETL   MEXICO (1401-09)
               SUMMIT HEIGHT 17930 FT (5465 M)
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SOURCES OF INFORMATION: GOES-8 VISIBLE AND MULTISPECTRAL IMAGERY.
1200 UTC MEXICO CITY SOUNDING. CENAPRED REPORT AND PUEBLA SURFACE
OBSERVATION. 
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ERUPTION DETAILS: ERUPTION AROUND 04/0823UTC GAS EMISSION AT 1245
UTC.
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DETAILS OF ASH CLOUD: GOES-8 MULTISPECTRAL IMAGERY THROUGH 1315 UTC
CONTINUES TO SHOW AN ELONGATED ASH CLOUD FROM THE 0823 UTC ERUPTION 
MOVING BOTH NORTHEAST AND EAST FROM POPOCATEPETL HOWEVER THE SOUTHERN
EXTENT OF THE FAINT ASH CLOUD IS NOW RAPIDLY BECOMING MORE FAINT.
THERE IS NO INDICATION IN IMAGERY FROM THE PUEBLA REPORT AT 1245 UTC 
OF AN ERUPTION AND IT HAS BEEN FOUND TO HAVE BEEN STEAM AND GAS.  THE
NORTHEASTERN POINT OF THE ASH HAS MOVED 300 KM (162 NMI) NORTHEAST
(47 DEGREES) FROM THE SUMMIT AND CONTINUES TO MOVE NORTHEAST AROUND
30 KNOTS PLACING IT AROUND FL240. THE SOUTHERN END OF THE ASH IS
MOVING EAST AROUND 20 KNOTS. AT 1315 UTC THE ASH CLOUD WAS ROUGHLY 40
KM (22 NMI) WIDE BETWEEN POINTS 20.87N 96.58W 20.19N 97.08W 19.80N
97.04W 19.15N 96.76W. THE FAINT ASH CLOUD CONTINUES SOUTH FROM 19.15N
96.76W TO 18.73N 96.57W TO 18.32N 96.31W. BECAUSE OF THE FAINT ASH
CLOUDS ORIGINAL SOUTHEAST MOTION FROM THE SUMMIT THE ESTIMATED HEIGHT
IS AROUND FL360.     
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TRAJECTORY: THE NORTH 1/3 OF THE ASH CLOUD IS MOVING NORTHEAST AROUND
30 KNOTS THE SOUTHERN 2/3 OF THE CLOUD IS MOVING EAST AROUND 20
KNOTS. 
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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/)
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OUTLOOK: SEE VAFTAD.
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THE NEXT MESSAGE FOR THIS EVENT WILL BE ISSUED BY 04/1730 UTC.
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PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS.
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"Attached Graphic Map Depicting Ash" 

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