Area Forecast Discussion
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000
FXPQ60 PGUM 250822
AFDPQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
622 PM CHST SAT OCT 25 2014

.MARIANAS SYNOPSIS...
LATEST ASCAT ANALYSIS REVEALS WEAK SURFACE TROUGHS TO THE WEST OF
THE MARIANAS NEAR 140E AND TO THE EAST OF THE MARIANAS NEAR 150E.
A VIGOROUS TUTT CELL IS CENTERED JUST WEST OF THE NORTHERN CNMI AT
18N144E. WATER VAPOR LOOP SUGGESTS DYNAMICS ON THE SOUTH SIDE OF
THE CELL HAVE BEEN IMPROVING DURING THE PAST SEVERAL HOURS. RADAR
AND SATELLITE INDICATE A SIGNIFICANT INCREASE IN THUNDERSTORM
COVERAGE...ESPECIALLY TO THE WEST OF GUAM OVER THE MARINE ZONES.
SHOWER COVERAGE REMAINS ISOLATED...FOR NOW.

&&

.DISCUSSION...
INGREDIENTS APPEAR TO BE FALLING INTO PLACE FOR THE FORMATION OF
AN MCS NEAR OR OVER THE FORECAST ZONES LATER THIS EVENING OR
TONIGHT. HOWEVER...RADAR AND SATELLITE COVERAGE...AS WELL AS
INITIAL MODEL SOLUTIONS...BOTH SUGGEST SHOWER COVERAGE OVERNIGHT
TONIGHT WILL REMAIN ISOLATED. AS A RESULT...CONFIDENCE IN THE
NEAR TERM FORECAST IS LOW. EVENING SHIFT WILL NEED TO MONITOR
RADAR AND SATELLITE FOR POSSIBLE UPDATES. AFTER TONIGHT...MOIST
UNSETTLED PATTERN CONTINUES THROUGH THE MIDDLE OF NEXT WEEK AS
DISTURBANCES EMBEDDED IN THE TRADES PASS THROUGH. GFS BRINGS
DRIER TRADES IN ON THURSDAY...BUT ECMWF SLOWLY DEVELOPS A MONSOON
DEPRESSION IN THE PHILIPPINE SEA NEXT WEEK...THEN KEEPS THE
FORECAST ZONES IN MOIST FLOW FROM THE SOUTH INTO THE FIRST WEEK
OF NOVEMBER. WILL CONTINUE TO LEAN TOWARD THE GFS...UNLESS
SATELLITE TRENDS CONFIRM THE ECMWF SOLUTION.

&&

.MARINE...
NO CHANGES TO THE ONGOING NARRATIVE. LATEST ALTIMETRY AND BUOY
READINGS CONFIRM LONG PERIOD NORTHEAST SWELL BETWEEN 6 AND 7 FEET
CONTINUING TO ARRIVE. STILL EXPECT SURF TO BEGIN SUBSIDING LATER
TONIGHT AND EVENTUALLY FALL BELOW ADVISORY HEIGHTS ON SUNDAY.
NEXT POSSIBLE HIGH SURF EVENT ON THE HORIZON WOULD BE ANOTHER
LONG PERIOD NORTHEAST SWELL EVENT TOWARD THE END OF NEXT WEEK.

&&

.EASTERN MICRONESIA...
AS A SURFACE TROUGH MOVES OUT OF THE REGION TONIGHT...POHNPEI AND
KOSRAE WILL BE BETWEEN A SURFACE RIDGE TO THE SOUTH AND TRADE-WIND
CONVERGENCE TO THE NORTH. THIS POSITIONING EQUATES TO MOSTLY CLOUDY
SKIES AND ISOLATED SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS.
MAJURO IS SITUATED WEST OF A CONVERGENCE ZONE. MODELS SHOW POHNPEI
AND KOSRAE IN THIS SAME POSITION OR CLOSE TO IT FROM TIME TO TIME
THE NEXT FEW DAYS. MAJURO REMAINS WEST OF THE CONVERGENCE ZONE WITH
SURFACE TROUGHS OCCASIONALLY COMING OFF OF THE CONVERGENCE ZONE AND
BRINGING PERIODS OF SHOWERS WESTWARD. MODEL SOLUTIONS DIVERGE AFTER
MONDAY NIGHT.

LONG-PERIOD NORTH-NORTHEAST SWELLS WILL MAINTAIN HAZARDOUS SURF
ACROSS CHUUK AND POHNPEI STATES UNTIL SUNDAY AFTERNOON. THESE SWELLS
CAN GENERATE SURF HEIGHTS OF 5 TO 6 FEET. COUPLING WITH SPRING HIGH
TIDES OF 4 TO 5 FEET AT MAJURO ATOLL...THE COMBINED SURF HEIGHTS
DURING HIGH TIDES WILL BE FROM 9 TO 11 FEET. THE IDEAL SURF HEIGHTS
CAPABLE OF CAUSING COASTAL INUNDATION ARE 12 FEET OR ABOVE. AS A
RESULT...NO INUNDATION IS EXPECTED DURING THIS SPRING HIGH TIDE
PERIOD AT MAJURO. HOWEVER THE RISK OF RIP CURRENTS WILL BE HIGHER
DURING HIGH TIDES FROM THIS AFTERNOON TO MONDAY AFTERNOON.

&&

.WESTERN MICRONESIA...
THE CIRCULATION AND ITS RELATED TROUGH THAT WERE NEAR POHNPEI THIS
MORNING ARE MOVING WESTWARD SOUTH OF CHUUK. ANOTHER WEAK TROUGH NEAR
POHNPEI THIS EVENING IS ALSO APPROACHING CHUUK. SCATTERED SHOWERS ARE
IN THE VICINITY OF WENO ISLAND THIS EVENING. AFTER THE PASSAGE OF
THESE FEATURES ON SUNDAY NIGHT...WEAK RIDGING FOLLOWING BEHIND
SHOULD USHER IN A QUIETER PERIOD. THEN EARLY NEXT WEEK...THE TRADE
CONVERGENCE ZONE CURRENTLY AFFECTING MAJURO SHOULD ARRIVE AT CHUUK
WITH MORE WET WEATHER. REFER TO THE SECOND PARAGRAPH UNDER THE
EASTERN MICRONESIA DISCUSSION ABOVE FOR HAZARDOUS SURF CONDITIONS
THRU SUNDAY MORNING.

THE WEAK MONSOON TROUGH NEAR KOROR AND YAP ACCORDING TO THE MODELS
REMAINS IN PLACE AROUND KOROR AND YAP THE NEXT FEW DAYS...BUT VERY
WEAK. WEATHER SHOULD REMAIN RELATIVELY BENIGN. TOWARD MIDWEEK...THE
CHANCE OF SHOWERS WILL INCREASE AS THE CIRCULATION CURRENTLY NEAR
POHNPEI MAKES ITS WAY WESTWARD TOWARD BOTH LOCALES. REMNANTS OF THE
NORTH-NORTHEAST SWELLS AFFECTING THE MARIANA ISLANDS ARE SCHEDULED
TO ARRIVE AT YAP STATE AND PALAU TONIGHT. SURF HEIGHTS SHOULD STAY
BELOW ADVISORY LEVELS BUT THE RISK OF RIP CURRENTS WILL BE HIGHER.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...HIGH SURF ADVISORY UNTIL 4 PM CHST SUNDAY FOR GUZ001>004.

MARIANAS WATERS...NONE.
&&

$$

MCELROY/DEVITA





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