Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Thu, 30 Dec 2010 01:28:35 -0600

410 
FXPQ60 PGUM 300728
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
528 PM CHST THU DEC 30 2010

.SYNOPSIS...
PGUA WSR-88D SHOWS ONLY A FEW SHOWERS OVER THE MARIANAS WATERS.
THE MARIANAS WATERS ARE BETWEEN A SHEAR LINE TO THE NORTH AND THE
DEEP TROPICAL MOISTURE TO THE SOUTH. THIS SHOULD PROMOTE DRIER
THAN NORMAL WEATHER FOR AT LEAST THE NEXT FEW DAYS.

&&

.DISCUSSION...
A SHEAR LINE IS STILL HUNG UP NEAR PAGAN IN THE FAR NORTHERN
MARIANAS...AND SHOULD REMAIN SO THROUGH FRIDAY. A SECONDARY PUSH
OF COLD AIR FROM OFF ASIA WILL NUDGE IT A LITTLE FURTHER SOUTH AND
EAST FRIDAY NIGHT AND SATURDAY. ECMWF AND GFS40 MODELS IN FAIR TO
GOOD AGREEMENT THAT IT WILL HANG UP AGAIN JUST NORTH OF SAIPAN.
FOR THE FORECAST ZONES THIS SHOULD CREATE A REGIME OF RELATIVELY
CLEAR SKIES...DRY AIR AND LIGHT WINDS. MOS SUPPORTS THIS
CONCLUSION...AND THESE CONDITIONS WILL CONSPIRE TO CREATE A GOOD
ENVIRONMENT FOR COOLER THAN USUAL NIGHTTIME LOW TEMPERATURES.
THEREFORE LOWERED THE TEMPERATURE FRIDAY NIGHT FROM 77 TO 75 TO
MATCH SATURDAY AND SUNDAY NIGHTS. DEEPER VALLEYS AROUND GUAM COULD
EASILY SEE TEMPERATURES IN THE MID TO UPPER 60S...BUT OUR GRIDS
JUST DO NOT HAVE THE RESOLUTION TO BE ABLE TO PUT THAT KIND OF
DETAIL IN. IF THE SHEAR LINE DOES COME A LITTLE FARTHER SOUTH WE
COULD HAVE SOME CLOUD COVER MONDAY OR TUESDAY TIME FRAME.

&&

.MARINE...
NORTHWEST SWELL IS EXPECTED TO INCREASE LATE SATURDAY NIGHT INTO
SUNDAY. SMALL CRAFT AND HIGH SURF ADVISORIES ARE EXPECTED...AND
COULD LAST FROM SUNDAY INTO WEDNESDAY.

&&

.EASTERN MICRONESIA...
SATELLITE IMAGERY SHOWS CONVERGING TRADE WINDS FOCUSING SOUTH OF 
KOSRAE CAUSING A BAND OF CLOUD COVER AND SCATTERED SHOWERS. 
OTHERWISE....GENERALLY DRY CONDITIONS WITH A SLIGHT INCREASE IN 
TRADE WINDS WILL CONTINUE OVER THE NEXT TWO DAYS. MODELS SHOW THE 
NEXT DISTURBANCE IS EXPECTED TO AFFECT POHNPEI OVER THE WEEKEND BUT 
FORECAST CONFIDENCE IS FAIRLY LOW AS MODEL SOLUTIONS DIVERGE 
APPRECIABLY DURING THIS PERIOD.

SWELL GENERATED BY A STRONG LOW PROGGED TO DEVELOP EAST OF JAPAN IS 
EXPECTED TO ARRIVE AT POHNPEI EARLY MONDAY MORNING AND KOSRAE BY 
MONDAY NIGHT. THIS MAY CAUSE SURF TO RISE ABOVE ADVISORY LEVELS. 
ALTHOUGH A DOWNWARD TREND IN SWELL HAS BEEN NOTICED IN THE PAST FEW 
WAVE WATCH RUNS...THE NORTH SWELL STILL LOOKS STRONG ENOUGH TO 
CREATE HIGH SURF CONDITIONS AT POHNPEI AND KOSRAE EARLY NEXT WEEK.

&&

.WESTERN MICRONESIA...
SATELLITE IMAGERY LATE THIS AFTERNOON SHOWS SCATTERED SHOWERS AND  
POSSIBLY THUNDERSTORMS IN AND AROUND THE YAP MARINE ZONE AND JUST 
ENTERING THE KOROR MARINE ZONE. LATEST ASCAT SHOWED THE TROUGH WAS 
WEST OF YAP AT 00Z LATE THIS MORNING. GENERALLY DRY CONDITIONS OVER 
EASTERN MICRONESIA WILL CONTINUE AT CHUUK THROUGH FRIDAY NIGHT 
BEFORE SHOWERS INCREASE OVER THE WEEKEND.

NORTH SWELL WILL ARRIVE SUNDAY FOR BOTH YAP AND KOROR WITH A HIGH
SURF ADVISORY LIKELY NEEDED BY SATURDAY AFTERNOON. SWELL SHOULD
ARRIVE LATE SUNDAY NIGHT AT CHUUK...WITH AN ADVISORY LIKELY BY
SUNDAY.

&&

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

$$

STANKO/DEVITA

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