High Surf Advisory 2, NWS Guam

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TIYAN GU
619 PM CHST SAT JAN 10 2015

.UPDATE...
UPDATED TO ADD MICRONESIA DISCUSSIONS.

&&

.MARIANAS SYNOPSIS...
A SHEAR LINE IS MOVING SLOWLY SOUTH THROUGH THE MARIANAS WATERS AND
IS NEAR ROTA AT 3 PM. ASCAT SHOWS WINDS 15-20 KT SOUTH OF THE LINE
AND 20-25 KT NORTH OF IT. CLOUDINESS AND ISOLATED SHOWERS ARE
PRESENT WITH THE SHEAR LINE. DOWN AROUND POHNPEI...THE DISTURBANCE
NOW DESIGNATED 92W HAS SHOWN LITTLE INCLINATION TO MOVE OR DEVELOP.
SEAS ARE RISING AT THE RITIDIAN BUOY AND HAVE REACHED 10 FEET AT
3 PM.

&&

.DISCUSSION...
LITTLE CHANGE IN THE FORECAST...AS THE SHEAR LINE IS NOW IN THE
MARIANAS AND WINDS ARE ON THE INCREASE. SHOULD BE MOSTLY CLOUDY
AND BREEZY THE NEXT FEW DAYS. SHOWERS ARE FORECAST TO BE ISOLATED
IN GENERAL...BUT AS THE DISTURBANCE NEAR POHNPEI MOVES WESTWARD
SOUTH OF GUAM THERE MAY BE A PERIOD OF SCATTERED SHOWERS MONDAY
NIGHT OR TUESDAY.

&&

.MARINE/SURF...
HAVE ISSUED A SMALL CRAFT ADVISORY STARTING MIDNIGHT...AS WINDS
ARE ALREADY INCREASING AND SEAS SHOULD BE NEAR 10 FEET BY LATE
SUNDAY--AND PERHAPS SOONER IF SEAS STAY UP AT RITIDIAN BUOY. HIGH
SURF IS A GOOD POSSIBILITY ALONG EAST FACING SHORES BY LATE SUNDAY
OR MONDAY. NORTH SWELL WAS EXPECTED TO PEAK AT 5 FEET...BUT IF
INDICATIONS OF HIGHER NORTH SWELL PERSIST AT THE RITIDIAN BUOY...
MIGHT NEED A HIGH SURF ADVISORY FOR NORTH FACING SHORES LATER
TONIGHT OR SUNDAY.

&&

.EASTERN MICRONESIA...
SATELLITE IMAGERY SHOWS A RELATIVELY NARROW BAND OF DEVELOPING
SHOWERS AND A FEW THUNDERSTORMS MOVING INTO MAJURO WATERS. THIS WILL
LIKELY BE A SHORT TERM AS DRIER CONDITIONS ARE EXPECTED TO RETURN
LATE TONIGHT. UNSETTLED WEATHER RETURNS SUNDAY NIGHT AT MAJURO AS A
DISTURBANCE TO THE SOUTHEAST IS EXPECTED TO MOVE OVER THE MARSHALL
ISLANDS. MODELS ARE IN GOOD AGREEMENT IN BRINGING DRIER WEATHER BACK
OVER THE MARSHALL ISLANDS BY MONDAY BEFORE ANOTHER UNSETTLED PATTERN
SETS IN FOR THE MIDDLE OF NEXT WEEK. GENERALLY QUIET WEATHER IS
EXPECTED AT KOSRAE TONIGHT AND SUNDAY. MODELS INDICATE THE
DISTURBANCE PROGGED TO AFFECT THE MARSHALL ISLANDS SUNDAY NIGHT WILL
WEAKEN AND PASS TO THE NORTH OF KOSRAE. NORTHEAST TRADE-WINDS AND
ISOLATED SHOWERS RETURN TO KOSRAE STATE LATE MONDAY INTO TUESDAY AS
ACTIVE WEATHER PUSHES TO THE WEST. VISIBLE SATELLITE IMAGERY
INDICATES THE DISTURBANCE/CIRCULATION SOUTH-SOUTHWEST OF POHNPEI
NEAR 3N157E IS BECOMING BETTER ORGANIZED IN TERMS OF CONVECTION AND
VORTICITY. HOWEVER...THE SYSTEM REMAINS ASYMMETRICAL AS UPPER-LEVEL
SHEAR FROM THE SOUTHEAST CONTINUES TO KEEP MOST OF THE CONVECTION TO
THE NORTHWEST OF THE CENTER WITH LITTLE NEW CONVECTIVE DEVELOPMENT
OBSERVED EAST OF 160E. WEATHER AT POHNPEI WILL BEGIN TO IMPROVE
SUNDAY AS THE SYSTEM FINALLY BEGINS TO PUSH WESTWARD INTO CHUUK
STATE.

&&

.WESTERN MICRONESIA...
A HEAVY CIRRUS SHIELD FROM CONVECTION TO THE SOUTHEAST OF WENO
REMAINS OVER CHUUK STATE. SHOWER AND THUNDERSTORM ACTIVITY WILL
INCREASE TONIGHT AND MOVE INTO CHUUK WATERS. AN EXTENDED PERIOD OF
UNSETTLED WEATHER IS PROBABLE AT CHUUK DURING THE NEXT FEW DAYS AS
THE DISTURBANCE TO THE SOUTHEAST DEVELOPS AND MOVES WESTWARD. MODELS
DISPLAY A GOOD CONSENSUS IN BRINGING CHUUK COPIOUS AMOUNTS OF RAIN
SO RAINFALL TOTALS...ESPECIALLY TONIGHT THROUGH SUNDAY NIGHT...WILL
HAVE TO BE CLOSELY MONITORED FOR MUDSLIDE POTENTIAL. WEATHER BEGINS
TO IMPROVE MONDAY NIGHT AS THE SYSTEM HEADS TOWARDS YAP STATE.

VIS SAT IMAGERY SHOWS SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A
TRADE-WIND DISTURBANCE MOVING INTO YAP WATERS. THIS FEATURE IS
RESOLVED DECENTLY IN THE GFS40 INDICATING DRIER CONDITIONS PUSHING
INTO YAP WATERS BY SUNDAY MORNING. DECREASED SHORT TERM WINDS AT YAP
AND KOROR AS SOUNDING DATA AND STREAM LINE ANALYSIS DO NOT SUPPORT
SUSTAINED 25 KT WINDS. THE SMALL DISTURBANCE IN YAP STATE IS
EXPECTED TO BEGIN TO AFFECT KOROR LATE TONIGHT INTO TOMORROW AS IT
MOVES INTO PALAU. HAVE ADJUSTED FORECAST ELEMENTS IN YAP AND KOROR
LONG TERM FORECAST TO INCLUDE AT LEAST A MODEST TROPICAL DISTURBANCE
MOVING THROUGH THE REGION TUESDAY AND WEDNESDAY. KEPT 11 FT COMBINED
SEAS AND 25 KT WINDS FOR BOTH YAP AND KOROR NEXT WEEK. GFS IS STILL
THE MOST AGGRESSIVE MODEL IN DEVELOPING THE DISTURBANCE
SOUTH-SOUTHWEST OF POHNPEI AND BRINGS THE SYSTEM THROUGH YAP STATE
AS A TROPICAL STORM TUESDAY. CONSIDERING THE SLOW EVOLUTION OF THE
SYSTEM...FELT IT NECESSARY TO EXCLUDE A TROPICAL STORM SCENARIO IN
THE LONG TERM FORECASTS FOR YAP AND KOROR.

ALTIMETRY INDICATES SEAS HAVE RISEN SLIGHTLY IN YAP STATE AND PALAU
AND WAVE WATCH CONTINUES TO SHOW A LARGE NORTH SWELL IMPACTING THE
REGION. HAZARDOUS SURF IS EXPECTED TO CONTINUE AT BOTH YAP AND KOROR
AT LEAST THROUGH THE WEEKEND BEFORE TRADE-WIND SWELL AND WAVES IN
ADDITION TO POSSIBLE SWELL AND WAVES GENERATED BY THE TROPICAL
DISTURBANCE IN POHNPEI STATE INCREASE MONDAY AND MONDAY NIGHT. THIS
MAY BRING A PROLONGED HIGH SURF EVENT TO YAP AND KOROR.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...NONE.
MARIANAS WATERS...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CHST THURSDAY
     FOR PMZ151>154.

&&

MIDDLEBROOKE/WILLIAMS