000
NOCA42 TJSJ 081837
PNSSJU
PRZ001>013>VIZ001-002-091600-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
230 PM AST THU MARCH 8 2007

...SAHARAN DUST ACROSS PUERTO RICO AND THE U.S. VIRGIN ISLANDS... 

LATEST SATELLITE IMAGES SHOWED A LARGE AREA OF SAHARAN DUST ACROSS 
PUERTO RICO AND THE U.S. VIRGIN ISLANDS THAT EXTENDED EASTWARD 
ACROSS THE LESSER ANTILLES INTO THE TROPICAL ATLANTIC. 

EVERY YEAR...AND MAINLY DURING THE HURRICANE SEASON...PULSES OF 
SAHARAN DUST GET CARRIED WESTWARD FROM THE WEST COAST OF AFRICA AT 
AN ALTITUDE OF AROUND 10 THOUSAND FEET. THE TRADE WINDS CARRY THE 
DUST OVER THE ATLANTIC AND IT ARRIVES TO THE LESSER ANTILLES ABOUT 
SEVEN DAYS LATER.

WHEN THE LOCAL WEATHER PATTERN REMAINS STABLE AND DRY LIKE IT HAS 
BEEN FOR WEEKS NOW...THE PRESENCE OF SAHARAN DUST USUALLY GIVES THE 
SKY A MILKY APPEARANCE. AS THE DUST TRAVELS ACROSS THE ISLANDS...AT 
TIMES IT MAY RESTRICT THE VISIBILITY. THIS SAHARAN DUST IS EXPECTED 
TO LINGER ACROSS THE AREA THROUGH AT LEAST SATURDAY. BY LATE SUNDAY 
A CHANGE IN THE WIND FLOW TO A MORE EAST TO NORTHEAST DIRECTION WILL 
ALLOW FOR CLEANER AIR TO MOVE INTO THE PUERTO RICO AND THE U.S. 
VIRGIN ISLANDS.

RM