Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Sat, 18 Dec 2010 15:54:18 -0600

296 
FXPQ60 PGUM 182153
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
753 AM CHST SUN DEC 19 2010

.SYNOPSIS...
PGUA WSR-88D SHOWS ISOLATED SHOWERS NEAR AND SOUTH OF GUAM WITH
ALMOST NO SHOWERS OVER THE NORTHERN MARIANAS WATERS. THE ZONE OF
SHOWERS IS SLIPPING TO THE SOUTH AND SHOULD HAVE LITTLE OR NO
AFFECT ON THE MARIANAS TODAY.

&&

.DISCUSSION...
GFS40 AND ECMWF-HIRES ONLY GRANT THE MARIANAS ABOUT 0.75 INCHES OF
RAINFALL OVER THE NEXT 10 DAYS...IF YOU SUBTRACT THE 0.45 INCHES
THE GFS40 SAYS SHOULD ALREADY HAVE FALLEN BUT DID NOT. LOOKS LIKE
DRY TIMES AHEAD AS DRY SEASON CONTINUES. THE KBDI FOR YESTERDAY OF
536 IS THE HIGHEST FOR DECEMBER 18 IN OUR WHOLE 53 YEAR DATABASE.
DRY SEASON STARTED EARLY AND STRONG...AND LOOKS TO STAY THAT WAY
THROUGH AT LEAST THE END OF THE YEAR. THE SHEAR LINE THAT WAS
MOVING TOWARD THE MARIANAS NOW LOOKS LIKE IT WILL STALL AND BEGIN
GRADUALLY WASHING OUT. THEREFORE UPDATED THE WINDS AND WIND
DEPENDENT GRIDS LIKE GUSTS AND WAVES...LOWERING THE COMBINED SEAS
AND THE SURF BY ABOUT A FOOT. LEFT THE CLOUDS IN FOR NOW BUT HAVE
A FEELING THOSE WILL DISAPPEAR FOR THE DAYTIME FORECAST THIS
AFTERNOON.

&&

.EASTERN MICRONESIA...
A DRY WEEK AHEAD IS EXPECTED FOR POHNPEI...KOSRAE AND MAJURO. A WEAK 
SURFACE TROUGH IS AIDING IN THE DEVELOPMENT OF A FEW SHOWERS JUST TO 
THE WEST OF POHNPEI BUT WILL STAY OUT OF THE MARINE ZONE AS THE 
SHALLOW CONVECTION CONTINUES TO PUSH WESTWARD. WINDS WILL BECOME 
VARIABLE AT TIMES AT KOSRAE AND MAJURO FOR THE NEXT COUPLE OF DAYS 
BUT WILL GENERALLY BE LIGHT OUT OF THE EAST AND SOUTHEAST. 
INCREASING TRADE WINDS SHOULD RETURN BY THE END OF THE WEEK.

&&

.WESTERN MICRONESIA...
THE DISTURBANCE PASSING POHNPEI MAY BRIEFLY BRING MOSTLY CLOUDY 
SKIES TO CHUUK INTO TONIGHT BUT SHOWER COVERAGE WILL REMAIN ISOLATED 
AS AN UPPER RIDGE OF HIGH PRESSURE CONTINUES TO SUPPRESS WIDESPREAD 
SHOWER ACTIVITY ACROSS THE AREA. OTHERWISE...FAIRLY DRY CONDITIONS 
ALONG WITH LIGHT TRADE WINDS WILL CONTINUE AT CHUUK THROUGH THE 
WEEK. IR IMAGERY SHOWS A NARROW BAND OF CONVECTION ALONG A 
CONVERGENT BOUNDARY JUST TO THE NORTHWEST OF YAP AND KOROR. MODELS 
INDICATE MORE CONVECTION WILL DEVELOP ALONG THIS BOUNDARY AND BRING 
THE ACTIVITY INTO KOROR BY THE AFTERNOON. HOWEVER...CURRENT ISOLATED 
COVERAGE OF CONVECTION...LACK OF A DEFINED SURFACE FEATURE AND 
LARGE-SCALE SUBSIDENT FLOW INDICATE THAT FURTHER WIDESPREAD 
DEVELOPMENT IS UNLIKELY AT THIS TIME. NONETHELESS...THE SHORT-TERM 
FORECAST FOR YAP AND ESPECIALLY KOROR WILL NEED TO WATCHED CLOSELY 
THROUGH MID-MORNING FOR A POSSIBLE FIRST PERIOD FORECAST UPDATE.

&&

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

$$

STANKO/WILLIAMS

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