Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Wed, 02 Jan 2008 00:59:48 -0600

993 
FXPQ60 PGUM 020659
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
459 PM CHST WED JAN 2 2008

.SYNOPSIS...
MODERATE TRADE WINDS ARE VERY DRY ACROSS THE MARIANAS RIGHT NOW
WITH NOTHING ON THE RADAR AND SFC DEWPOINTS AROUND 70F. VIS
SATELLITE SHOWS TRADE WIND SHOWERS UPWIND THAT MAY MOVE IN
OVERNIGHT. STRONG SHEAR LINE 400 MILES NW OF MARIANAS HAS BEEN
STATIONARY ALL DAY. NW SWELL GENERATED BY STRONG WINDS NORTH OF
THE SHEAR LINE HAVE ARRIVED IN THE MARIANAS AND ARE PRODUCING HIGH
SURF.

&&

.DISCUSSION...
GFS BRINGS THE SHEAR LINE CLOSER OVER THE NEXT FEW DAYS BUT KEEPS
IT NORTH OF SAIPAN THRU 120 HRS...AS DOES THE UKMET THRU 72 HRS.
NOGAPS REPRESENTS THE MINORITY OPINION...KEEPING THE SHEAR LINE
JUST NW OF US BUT BRINGING A SMALL TRADE-WIND DISTURBANCE THROUGH
THE ISLANDS THU AND FRI. WILL STAY WITH GFS/UK..AS NOTHING UPSTREAM
ON SATELLITE SUGGESTS THE NOGAPS SCENARIO. THEREFORE...HAVE TAKEN
OUT MOSTLY CLOUDY AND WILL STAY WITH PC/ISOL SHOWERS. ALMOST WENT
WITH SLGT CHC OF SHOWERS OVERNIGHT...BUT ISOL TRADE SHOWERS UPWIND
ON SATELLITE COULD ARRIVE BY MIDNIGHT.

&&

.MARINE/SURF...
NW SWELL HAS ARRIVED AND SURF IS HITTING 10 TO 11 FT ON N AND NW
EXPOSURES OF GUAM. EXTENDED THE HIGH SURF ADVY THROUGH FRI
AFTERNOON ACCORDING TO LATEST WAVE MODEL GUIDANCE. A SMALL CRAFT
ADVY WILL PROBABLY BE NEEDED LATE THU OR THU NITE AS COMBINED SEAS
NEAR 10 FEET. 

&&

.EASTERN MICRONESIA...
LITTLE CHANGE TO FORECAST REASONING. CONVECTION DRIVEN BY TRADE-WIND 
CONVERGENCE LOOKS TOO WEAK ON BOTH SATELLITE AND IN THE MODELS TO 
JUSTIFY SCATTERED COVERAGE DURING THE FORECAST PERIOD. PRIMARY 
FORECAST CONCERN REMAINS THE TRADE-WIND SURGE AND RELATED HIGH SURF 
EVENT CURRENTLY IN PROGRESS. EVENT AT MAJURO LOOKS ROBUST ENOUGH FOR 
A HIGH SURF WARNING ON FRIDAY ON EAST-FACING EXPOSURES. LATEST WAVE 
WATCH RUN HAS TRENDED UP A FOOT ON FRIDAY...THUS WOULD RECOMMEND THE 
NIGHT SHIFT UPGRADE THE ADVISORY TO A WARNING ON MAJURO FOR FRIDAY. 
FOR KOSRAE...STILL LOOKS LIKE SURF WILL BUILD TO HAZARDOUS HEIGHTS 
ON NORTH AND EAST-FACING EXPOSURES THURSDAY. NIGHT SHIFT WOULD BE A 
GOOD TIME TO PICK UP KOSRAE ON THE HIGH SURF LIST. HIGH SURF EVENT 
ON MAJURO AND KOSRAE LOOKS TIMED TO END ON SUNDAY.

&&

.WESTERN MICRONESIA...
WEATHER HERE LOOKS RELATIVELY DRY...EXCEPT FOR THE OVERNIGHT PERIOD 
ON YAP. A TRADE-WIND DISTURBANCE IS CURRENTLY SEEN IN VISIBLE 
SATELLITE IMAGERY BEARING DOWN ON YAP FROM THE EAST-NORTHEAST. AWIPS 
DISTANCE/SPEED TOOL GIVES A GUST FACTOR A HAIR BELOW 30 KT...SO WAS 
CONSERVATIVE WITH A GUST FACTOR OF 25 KT. AGAIN...MAIN FORECAST 
CONCERN HERE IS HIGH SURF. TWEAKED AFFECTED EXPOSURES TO NORTH BASED 
UPON FETCH ORIENTATION SEEN ON THE MORNING QUIKSCAT IMAGERY AND WAVE 
WATCH TABULAR DATA. OTHERWISE...LOOKS LIKE NORTH SWELL ENERGY WILL 
PEAK THURSDAY AND FRIDAY. EXPECT SURF TO DROP BELOW 9 FT BY SUNDAY 
ON KOROR AND YAP.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...HIGH SURF ADVISORY UNTIL 6 PM CHST FRIDAY FOR GUZ001>004.

MARIANAS WATERS...NONE.
&&

$$

MIDDLEBROOKE/MCELROY

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