Subject: Western Pacific: Synoptic Discussion For The Marianas

From: LDM Weather <[email-masked]>
Date: Mon, 27 Dec 2010 01:32:58 -0600

658 
FXPQ60 PGUM 270732
AFDPQ 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
532 PM CHST MON DEC 27 2010

.SYNOPSIS...
WEAK INVERTED SURFACE TROUGH IS LOCATED JUST EAST OF THE FORECAST
ZONES. NARROW BAND OF SHOWERS ASSOCIATED WITH THE TROUGH IS MOVING
THROUGH NOW...BUT ANIMATED RADAR AND VISIBLE SATELLITE IMAGERY
SUGGESTS OVERALL SHOWER COVERAGE WILL BE ISOLATED OVERNIGHT.

&&

.DISCUSSION...
AFTER THE SURFACE TROUGH MOVES THROUGH...WEATHER PATTERN LOOKS
RATHER BLAND. DEEP LAYER RIDGING WILL REMAIN IN CONTROL THROUGH
SATURDAY...THEN A COLD FRONT/SHEAR LINE APPROACHES ON SUNDAY.
LATEST GFS RUNS HAVE TRENDED TOWARD STALLING THIS BOUNDARY NORTH
OF SAIPAN...SO WILL HOLD OFF ON ADDING ANY DETAIL TO THE FORECAST
GRIDS DURING THIS TIME FRAME. GFS AND TO A LESSER EXTENT THE ECMWF
HINT AT MOISTURE MOVING IN FROM SOUTHEAST THAT COULD COMPLICATE
THE FORECAST NEXT MONDAY AND TUESDAY.

&&

.MARINE...
IPAN BUOY COMES IN WITH A SIGNIFICANT SWELL HEIGHT BETWEEN 3 AND 4 
FEET...SO WENT AHEAD AND TRIMMED A FOOT FROM THE INITIAL TRADE-WIND 
SWELL HEIGHTS. WAVE WATCH MODEL IS STILL BRINGING IN LONG PERIOD 
SWELLS AS HIGH AS 11 FEET FROM THE NORTHWEST BEGINNING ON SUNDAY. 
MODELS ARE IN GENERAL AGREEMENT ON THE STRENGTH OF THE COLD FRONT 
PUSHING SOUTHEASTWARD FROM JAPAN DURING THIS TIME FRAME...THUS WOULD 
NOT BE SURPRISED TO SEE COMBINED SEAS AT OR ABOVE 10 FEET AND A 
ROBUST HIGH SURF EVENT THIS WEEKEND FOR WEST AND NORTH FACING 
EXPOSURES.

&&

.EASTERN MICRONESIA...
A NARROW BAND OF CONVECTION CURVES WESTWARD ACROSS THE REGION ENDING 
SOUTH OF CHUUK. THIS SYSTEM HAS BROUGHT SHOWERS TO BOTH KOSRAE AND 
MAJURO. VISIBLE IMAGERY SHOWS THESE SHOWERS TRAINING ACROSS 
MAJURO...BUT LIFTING JUST NORTH OF KOSRAE. BECAUSE OF 
THIS...SCATTERED SHOWERS REMAIN OVERNIGHT FOR MAJURO AND FOR 
NORTHERN WATERS OF KOSRAE. SOUTHEASTERLY FLOW EAST OF MAJURO SHOULD 
PUSH THE BELT OF SHOWERS JUST NORTH OF MAJURO TOMORROW. MODEL 
GUIDANCE DEVELOPS ANOTHER TROUGH IN THE MARSHALLS BY MIDWEEK 
BRINGING MORE CLOUDS AND SHOWERS FOR THE LAST HALF OF THE WEEK 
ACROSS THE REGION.

&&

.WESTERN MICRONESIA...
A TROUGH NEAR POHNPEI THIS MORNING CONTINUES MOVING TOWARD CHUUK.
CLOUDS AND SCATTERED SHOWERS WILL DEVELOP BY TOMORROW...WITH
CLEARING BY WEDNESDAY NIGHT AS THE TROUGH MOVES WEST. FARTHER
WEST...A NEAR-EQUATORIAL TROUGH CONTINUES TO INFLUENCE WEATHER
NEAR KOROR. SATELLITE AND LIGHTNING DATA INDICATE THUNDERSTORMS IN
THE AREA...WITH COLD CONVECTIVE CLOUD TOPS JUST SOUTHEAST OF
KOROR. FORECAST FOR TONIGHT WILL CARRY ISOLATED THUNDERSTORMS AT
KOROR...WITH SCATTERED SHOWERS TOMORROW TAPERING TO ISOLATED.
EARLIER MODEL RUNS VARIED A BIT IN WIND DIRECTIONS AND SHOWERS
FOR THE END OF THE WEEK...BUT LATEST RUN SMOOTHS THINGS OUT A BIT
WITH A MORE CONSISTENT NORTHEAST TO EAST TRADE WIND FLOW INTO THE
WEEKEND.

&&

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

$$

MCELROY/M. AYDLETT

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