FVXX22 KWBC 161100
VOLCANIC ASH ADVISORY STATEMENT
ISSUED 1045 UTC 16 DEC 1999 BY THE WASHINGTON VAAC 
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SAN CRISTOBAL 99-020 NICARAGUA 12.7N 87.0W 
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BACKGROUND:    SAN CRISTOBAL NICARAGUA (1404-02)
               SUMMIT HEIGHT 5725 FT (1745 M)
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SOURCES OF INFORMATION: GOES-8 VISIBLE INFRARED AND MULTISPECTRAL
IMAGERY...0000 UTC AVIATION MODEL WIND FORECAST
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ERUPTION DETAILS: LIGHT VENTING OF GASES AND POSSIBLY ASH.
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DETAILS OF ASH CLOUD:   THE PLUME OBSERVED YESTERDAY COULD BE SEEN
ONLY IN VISIBLE SATELLITE IMAGERY AND COULD NOT BE DISCERNED IN
INFRARED OR MULTISPECTRAL IMAGERY.  THEREFORE SINCE NIGHTFALL WITH
ONLY INFRARED AND MULTISPECTRAL SATELLITE IMAGERY AVAILABLE IT HAS
NOT BEEN POSSIBLE TO SEE THE PLUME.
     HOWEVER IN THE LAST VISIBLE SATELLITE IMAGES OF DECEMBER 15 A
FAINT PLUME OF ASH OR GASES AT ABOUT FL080 WAS SEEN EXTENDING FROM
THE VOLCANO TOWARD THE WEST SOUTHWEST.  AT 15/2245 UTC THE PLUME WAS
300 KM (162 NMI) LONG AND REACHED THE POINT 11.5N 89.5W OVER THE
PACIFIC OCEAN. 
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TRAJECTORY: UPPER AIR PATTERNS SUGGEST THAT ANY ASH BETWEEN FL050
AND FL100 WILL MOVE TO THE WEST OR SOUTHWEST AT 10 TO 20 KNOTS.
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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/)
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OUTLOOK:  SEE LATEST SIGMETS.
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EFFECTIVE JANUARY 3 2000 AT 0000 UTC... ALL REFERENCES TO LATITUDE
AND LONGITUDE IN VOLCANIC ASH ADVISORY STATEMENTS WILL BE IN DEGREES
AND MINUTES OF A DEGREE. EXAMPLE: 16.70N 62.20W  WILL BE  1642N6212W
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THE NEXT STATEMENT WILL BE ISSUED BY 16/1700 UTC.
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PLEASE REFER TO SIGMETS FOR CURRENT WARNINGS.
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STREETT
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