Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Thu, 07 Feb 2008 01:51:38 -0600

303 
FXPQ60 PGUM 070751
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
551 PM CHST THU FEB 7 2008

.SYNOPSIS...
THE SUBTROPICAL SURFACE RIDGE HAS SAGGED SOUTHWARD...AND ITS AXIS 
EXTENDS WESTWARD ACROSS PAGAN ISLAND. SOUTH WINDS ALONG THE RIDGE
AXIS ARE BLOWING THE GAS PLUME FROM ANATAHAN NORTHWARD...AND IT IS
SITUATED JUST WEST OF ALAMAGAN...PAGAN AND AGRIHAN ISLANDS.
OTHERWISE...MODERATE TRADES CONTINUE ACROSS THE ISLANDS FROM SAIPAN
SOUTH TO GUAM...AND VISIBLE SATELLITE SHOWS PATCHY CLOUDINESS AND
ISOLATED LIGHT TRADE-WIND SHOWERS. MEANWHILE...A SHEAR LINE IS
APPROACHING THE REGION FROM THE NORTHWEST...AND IS NOW ABOUT 120
MILES NW OF AGRIHAN.

&&

.DISCUSSION...
ANATAHAN'S PLUME MAY BRING A SULFEROUS SMELL TO THE ISLANDS NORTH
OF THE VOLCANO OVERNIGHT...BUT THAT SHOULD END ON FRIDAY AS THE
SHEAR LINE MOVES IN AND WINDS SWING BACK TO NORTHEAST. FOR GUAM
THROUGH SAIPAN MORE DRY WEATHER IS IN STORE...AS MODELS ALL SHOW A
DRY TRADE WIND PATTERN PERSISTING FOR THE NEXT WEEK.

&&

.MARINE/SURF...
AN UNEXPECTEDLY LARGE NORTH-NORTHWEST SWELL HAS BRIEFLY BROUGHT
SURF UP TO 8 FEET ON NORTH FACING REEFS TODAY...BUT MODEL GUIDANCE
INDICATES THIS SHOULD SUBSIDE OVERNIGHT AND FRIDAY. THE NEXT HIGH
SURF EVENT COULD BE AROUND THE MIDDLE OF NEXT WEEK...WHEN A FRESH
BATCH OF NORTH SWELL IS DUE TO ARRIVE.

&&

.EASTERN MICRONESIA...
FORECAST IS ALMOST IDENTICAL AS PREVIOUS EXCEPT SHOWERS MIGHT LINGER 
INTO SUNDAY FOR KOSRAE AS BEING SUGGESTED BY THE MODELS. THE LEADING 
EDGE OF TRADE CONVERGENCE IS SLIDING INTO POHNPEI THIS EVENING...
WHILE THE CONVERGENCE BOUNDARY ITSELF IS STILL OVER KOSRAE. MAJURO
WILL BE NORTH OF THE MAIN ACTIVITY THROUGH THE PERIOD.

HIGH SURF STILL HOLDING FOR KOSRAE AND MAJURO THROUGH FRIDAY. NO 
NEED TO UPDATE THE ADVISORY ITSELF. LATEST GUIDANCE SUGGESTS SURF 
HEIGHTS OVER POHNPEI MIGHT STAY BELOW ADVISORY CRITERIA AFTER ALL. 
NEED TO KEEP MONITORING THIS EVENING AND FRIDAY.

&&

.WESTERN MICRONESIA...
BASED ON VISIBLE SATELLITE TODAY...CONVECTION ASSOCIATED WITH THE 
WEAK CIRCULATION NEAR THE EQUATOR IS STAYING JUST SOUTH OF KOROR. 
THERE HAS BEEN LOTS OF HIGH CLOUDS OVER PALAU BUT NOT MUCH SHOWERS.
MODELS ARE ALSO DELAYING ARRIVAL OF SHOWERS UNTIL FRIDAY EVENING.
DUE TO THE LACK OF ADVANCEMENT FROM THE CIRCULATION ITSELF...
PUSHED BACK SHOWERS UNTIL LATE FRIDAY NIGHT. MODELS THEN TRY TO
BREAK THE DRY SPELL OVER YAP ON SUNDAY BY INTRODUCING THE
CONVERGENCE AREA CURRENTLY OVER EASTERN MICRONESIA. WITH ENOUGH
UPPER-LEVEL DIVERGENCE PRESENT AT THE SOUTHWESTERN QUADRANT OF THE
HIGH...IT SEEMS LOGICAL AT THIS POINT. SHOWERS SEEM TO BE TAKING
THEIR TIME MOVING TOWARD CHUUK. THEREFORE ALSO PUSHED BACK WETNESS
UNTIL FRIDAY MORNING AS WELL.

&&

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

$$

MIDDLEBROOKE/CHAN

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