437
FXPQ50 PGUM 030704
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
504 PM CHST FRI APR 3 2026
MARIANAS SYNOPSIS
A FAIRLY DRY TRADE-WIND PATTERN EXTENDS ACROSS THE AREA WITH RADAR
SHOWING ISOLATED TRADE SHOWERS MOVING THROUGH THE FLOW. WINDS ARE
GENTLE TO MODERATE AND SEAS ARE AROUND 4 TO 6 FEET ACCORDING TO BUOY
AND ALTIMETRY DATA. EXPECTING SEAS AND WINDS TO BUILD THIS WEEKEND
AS A TRADE-WIND SURGE DEVELOPS EAST OF THE MARIANAS.
DISCUSSION
THIS SEASONAL TRADE-WIND PATTERN IS EXPECTED THROUGH THE MIDDLE OF
NEXT WEEK AS SATELLITE IMAGERY ONLY SHOWS A COUPLE OF WEAK TRADE-
WIND TROUGHS MOVING THROUGH THE FLOW TO THE EAST OF THE MARIANAS. THE
LEADING EDGE OF A DEVELOPING TRADE-WIND SURGE NEAR THE MARSHALL
ISLANDS IS EXPECTED TO INCREASE WINDS TO MODERATE TO FRESH STARTING
SATURDAY, WITH BREEZY CONDITIONS DURING THE DAYTIME HOURS OF SUNDAY
AND MONDAY. WINDS ARE THEN EXPECTED TO SUBSIDE SLIGHTLY TUESDAY AND
WEDNESDAY AS THE TRADE-WIND SURGE WEAKENS AND SHIFTS BACK TOWARDS
THE EAST. LONG-RANGE GUIDANCE WEAK TROPICAL DISTURBANCE IN EASTERN
MICRONESIA WILL SLOWLY SHIFT WESTWARD INTO CENTRAL MICRONESIA BEFORE
POTENTIALLY LIFTING NORTHWARD AND CLOSER TO THE MARIANAS NEXT
WEEKEND. THIS WOULD INCREASE THE POTENTIAL FOR SHOWERS,
THUNDERSTORMS, AND SOME GUSTY WINDS AROUND THE MARIANAS, BUT THIS IS
STILL AT LEAST 7 TO 10 DAYS OUT SO UNCERTAINTY IN THE FORECAST
REMAINS FAIRLY HIGH AT THIS TIME.
MARINE
GENTLE TO MODERATE NORTHEAST WINDS AND COMBINED SEAS OF 4 TO 6
FEET PREVAIL ACROSS THE REGION TONIGHT. A TRADE-WIND SURGE WILL THEN
DEVELOP OVER THE WEEKEND, RESULTING IN WINDS INCREASING TO MODERATE
TO FRESH ACROSS THE MARIANAS, AND GETTING CLOSE TO 22 KT SUNDAY AND
MONDAY. AN INCREASE IN TRADE-WIND SWELL AND WIND WAVES WILL ALSO
BUILD SEAS TO 6 TO 9 FEET OVER THE WEEKEND. THEN, NORTHERLY SWELL
LOOKS TO ARRIVE MONDAY, WHEN SEAS ARE ANTICIPATED TO REACH 9 TO 11
FEET, BECOMING HAZARDOUS FOR SMALL CRAFT. WINDS AND SEAS ARE THEN
EXPECTED TO SUBSIDE SLIGHTLY AROUND MIDWEEK. A MODERATE RISK OF RIP
CURRENTS ALONG NORTH AND EAST FACING REEFS AND LOW RISK ALONG SOUTH
AND WEST FACING REEFS CONTINUES OVER THE NEXT COUPLE DAYS, WITH THE
PRIMARY SWELL FROM THE NORTHEAST. AN INCREASE IN EAST-NORTHEAST TRADE
WINDS AND SWELL OVER THE WEEKEND AND THE ARRIVAL OF NORTHERLY SWELL
ON MONDAY ARE EXPECTED TO BUILD SURF ALONG EAST AND NORTH FACING
REEFS, LIKELY INCREASING THE RIP RISK TO HIGH FOR EAST-FACING REEFS
STARTING SUNDAY AND POTENTIALLY PRODUCING HAZARDOUS SURF OF 9 FEET
FOR NORTH-FACING REEFS.
EASTERN MICRONESIA
SATELLITE IMAGERY SHOWS PARTLY TO MOSTLY CLOUDY SKIES AND ISOLATED
TO SCATTERED SHOWERS ACROSS EASTERN MICRONESIA. ALTIMETRY DATA SHOWS
COMBINED SEAS BETWEEN 5 AND 8 FEET ACROSS THE REGION.
OVERALL, LITTLE HAS CHANGED WITH THE OBSERVED WEATHER ACROSS EASTERN
MICRONESIA. SHOWER COVERAGE HAS BEEN LOWER THAN EXPECTED ACROSS
MAJURO WITH SCATTERED SHOWERS SEEN, WHILE ISOLATED SHOWERS ARE
OCCURRING NEAR POHNPEI AND KOSRAE. THE MAIN FORECAST TREND WAS TO
DIAL DOWN POPS A BIT AND DELAY WIDESPREAD RAINFALL CONDITIONS. THIS
FORECAST HAD A HEAVY LEAN TOWARDS THE ECMWF, WHICH BETTER REFLECTED
THE CURRENT OBSERVATIONS THAN THE GFS. DESPITE THE DOWNTREND,
NUMEROUS SHOWERS ARE EXPECTED THIS WEEKEND AND INTO NEXT WEEK FOR
MAJURO AND THEN KOSRAE AND POHNPEI. AS THE TROPICAL DISTURBANCE
ORGANIZES, WIDESPREAD SHOWERS ARE EXPECTED AT POHNPEI AND KOSRAE
TOWARDS THE END OF THE PERIOD.
OVERALL, THERE IS LITTLE CHANGE IN THOUGHT FOR MARINE CONDITIONS.
COMBINED SEAS ARE BETWEEN 5 AND 8 FEET ACROSS THE REGION. A TRADE-
WIND SWELL WILL ALLOW SEAS TO RISE ANOTHER FOOT. FOR KOSRAE AND
MAJURO, SEAS LOOK TO REMAIN BENIGN OUTSIDE OF SHOWERS AND
THUNDERSTORMS, BUT COULD BECOME CHOPPY DURING SHOWERS. FOR POHNPEI,
THE TRADE-WIND SWELL LOOKS JUST MISS TO THE NORTH, BUT SEAS LOOK TO
RISE ENOUGH TO CAUSE HAZARDOUS SURF FOR NORTH FACING REEFS.
WESTERN MICRONESIA
AFTERNOON SATELLITE IMAGERY SHOWS THE NEAR-EQUATORIAL TROUGH (NET)
REMAINS TO THE SOUTH OF THE THREE FORECAST POINTS WITH ISOLATED TO
SCATTERED SHOWERS NOTED ALONG THE NET AXIS. SCATTERED SHOWERS ARE
EXPECTED AT BOTH PALAU AND CHUUK TONIGHT WHILE SHOWERS REMAIN
ISOLATED AT YAP. SHOWER CHANCES SHOULD REMAIN ISOLATED AT ALL THREE
SITES ON SATURDAY. A WET PATTERN IS EXPECTED AT CHUUK STARTING
SATURDAY NIGHT WITH SHOWER CHANCES INCREASING TO NUMEROUS BY SUNDAY
NIGHT. ISOLATED THUNDERSTORMS AND LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE AT CHUUK STARTING LATE ON SUNDAY AS A TRADE-WIND SURGE NEAR
THE MARSHALL ISLANDS MOVES WESTWARD. GENTLE TO MODERATE NORTHEAST
WINDS ARE EXPECTED TO PREVAIL AT PALAU AND YAP THROUGH THE WEEKEND,
THOUGH YAP MAY EXPERIENCE PERIODS OF LOW-END FRESH WINDS STARTING ON
SUNDAY. GENTLE TO MODERATE NORTHEAST WINDS AT CHUUK WILL QUICKLY
BECOME MODERATE TO FRESH STARTING ON SATURDAY WITH A POTENTIAL FOR
STRONG WINDS STARTING ON SUNDAY AS THE TRADE-WIND SURGE IS EXPECTED
TO IMPACT CENTRAL MICRONESIA. ATTENTION THEN TURNS TO MID TO LATE
NEXT WEEK AS A TROPICAL DISTURBANCE IS FORECAST TO IMPACT CENTRAL
MICRONESIA.
ALTIMETRY PASSES FROM THIS MORNING SHOW SEAS AROUND 4 FEET JUST WEST
OF PALAU AND SEAS 4 TO 6 FEET IN THE VICINITY OF CHUUK. COMBINED
SEAS WILL REMAIN AROUND 3 TO 5 FEET AT PALAU THROUGH THE WEEKEND,
BUILDING BY A FOOT OR SO AS WE HEAD INTO NEXT WEEK. SEAS WILL
INCREASE AT YAP TO AROUND 6 TO 7 FEET BY MONDAY. CHUUK'S SEAS WILL
INCREASING SIGNIFICANTLY, LIKELY TO HAZARDOUS TO SMALL CRAFT OF 10
FEET, STARTING ON SUNDAY AS A TRADE-WIND SURGE AND A NORTHEAST SWELL
MOVE IN. HAVE ADDED A HEADLINE FOR BUILDING SEAS AND HIGH SURF ALONG
NORTH FACING REEFS FOR CHUUK STARTING ON SUNDAY. A SMALL CRAFT
ADVISORY STARTING ON SUNDAY IS LIKELY FOR THE COASTAL WATERS OF
CHUUK, WITH THE POTENTIAL FOR A HIGH SURF ADVISORY ALONG AT THE LEAST
NORTH FACING REEFS ALSO POSSIBLE LATE THIS WEEKEND AND INTO EARLY
NEXT WEEK.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: SCHANK
EAST MICRONESIA: WILLIAMS
WEST MICRONESIA: WHISNANT
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