Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Thu, 23 Dec 2010 14:07:35 -0600

175 
FXPQ60 PGUM 232007
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
607 AM CHST FRI DEC 24 2010

.SYNOPSIS...
VERY DRY AIR WAS FILTERING INTO THE FORECAST DOMAIN FROM THE
NORTH. DEW POINTS AT THE GUAM INTERNATIONAL AIRPORT HAVE EVEN
DROPPED BELOW 70 DEGREES AT TIMES DURING THE OVERNIGHT HOURS. THE
NEAREST AREA OF CLOUDINESS WAS ASSOCIATED WITH AN INVERTED
SURFACE TROUGH EAST OF THE MARIANAS NEAR 149E.

&&

.DISCUSSION...
GFS INITIAL MODEL FIELDS ALSO SUGGEST WEATHER TODAY WILL BE
ESPECIALLY DRY...SO HAVE TRIMMED FIRST PERIOD POPS TO SLIGHT
CHANCE. OTHERWISE...A RELATIVELY DRY WEATHER PATTERN REMAINS IN
PLACE WITH NO SIGNIFICANT WEATHER MAKERS IN SIGHT. NEXT SHEAR
LINE SHOULD STALL AROUND ANATAHAN ON SATURDAY...THEN BOOMERANG
BACK TO THE NORTH. PRIMARY EFFECT OF THIS SYSTEM WILL BE TO BRING
IN A NORTH SWELL BEGINNING ON SATURDAY...BUT SWELL HEIGHTS LOOK
MODEST. SURF ZONE FORECAST STILL ANTICIPATES MODERATE RIP CURRENT
RISK ON NORTH AND EAST FACING REEFS THROUGH AT LEAST EARLY NEXT
WEEK.

&&

.EASTERN MICRONESIA...
THE SOUTHWESTERN END OF A COLD FRONT WILL PASS OVER THE NORTHERN
MARSHALLS TODAY. THE FRONT WILL CONTINUE TO DISPLACE THE SURFACE
RIDGE EASTWARD TOWARD THE DATE LINE. THE DEPARTING RIDGE WILL
PROVIDE ANOTHER 24 TO 36 HOURS OF DRY WEATHER FOR BOTH KOSRAE AND
MAJURO. ANOTHER RIDGE OF HIGH PRESSURE NORTHWEST OF THE COLD
FRONT WILL ALSO MAINTAIN A DRY REGIME AND GENTLE WINDS OVER
POHNPEI AND CHUUK INTO SATURDAY. AS THIS RIDGE OF HIGH PRESSURE
DRIFTS CLOSER TO THE DATE LINE ON SUNDAY...IT WILL BEGIN TO
DIRECT MUCH STRONGER TRADES ACROSS THE DATE LINE TOWARD EASTERN
MICRONESIA. AS A RESULT...TRADE-WIND CONVERGENCE INDUCED SHOWERS
WILL BE ON THE RISE OVER ALL THE ABOVE LOCATIONS BY EARLY NEXT
WEEK.

A NORTHEAST SWELL WILL GENERATE HIGHER SURF ON CHUUK AND POHNPEI
THIS AFTERNOON THRU SATURDAY. LATEST SATELLITE-DERIVED SEA
HEIGHTS SUGGEST SURF WILL NOT REACH ADVISORY LEVELS ON EITHER OF
THESE LOCATIONS. BUILDING TRADE-WIND SWELLS AND WAVES WILL BEGIN
TO IMPACT THE MARSHALLS WESTWARD TO CHUUK BY EARLY NEXT WEEK.
THIS COULD PRODUCE A HIGH SURF EVENT ON KOSRAE BY SUNDAY...WHICH
NEEDS TO BE MONITORED.

&&

.WESTERN MICRONESIA...
THE AFOREMENTIONED RIDGE OF HIGH PRESSURE NORTH OF CHUUK IS
NUDGING THE NEAR-EQUATORIAL TROUGH FARTHER TO THE SOUTH OF KOROR.
THIS WILL ALLOW MUCH DRIER AIR AT MID TO UPPER LEVELS TO DOMINATE
BOTH YAP AND KOROR THRU THE WEEKEND AS LIGHT NORTHEAST TRADES
FILTER OVER KOROR FROM THE NORTH. HOWEVER...A SHEAR LINE FRAGMENT
LOCATED BETWEEN GUAM AND YAP MIGHT BRING CLOUDINESS AND A FEW
SHOWERS OVER YAP THIS EVENING AND SATURDAY. TRADE-WIND CONVERGENCE
ENCROACHING FROM THE EAST IS EXPECTED INTRODUCE A WETTER PATTERN
NEXT WEEK.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...NONE.
&&

$$

MCELROY/CHAN

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