004
FXPQ50 PGUM 012009
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
609 AM CHST THU APR 2 2026
MARIANAS UPDATE
RADAR AND SATELLITE EARLY THIS MORNING DEPICT SHALLOW, PATCHY
ISOLATED TO SCATTERED SHOWERS MOVING SOUTHWEST ACROSS MARIANAS
COASTAL WATERS, WITH FAIRLY UNIFORM CONDITIONS UPSTREAM. THERE WAS
VERY LITTLE CHANGE TO THE FORECAST. MODEL GUIDANCE DEPICTS AN
INCREASE IN SHOWERS LATE TONIGHT THROUGH EARLY TOMORROW MORNING AS A
BROAD, BUT SHALLOW TROUGH CROSSES THE AREA. THIS MAY BRIEFLY
INTERRUPT WHAT WILL OTHERWISE REMAIN A RELATIVELY DRY PATTERN OVER
THE NEXT SEVERAL DAYS, AND SCATTERED SHOWERS WERE INCLUDED IN THE
FORECAST DEVELOPING AFTER MIDNIGHT.
LATEST BUOY AND ALTIMETRY DATA SHOW COMBINED SEAS AROUND 5 TO 7 FEET
ACROSS THE MARIANAS, WHICH ARE EXPECTED TO DIMINISH TO 4 TO 6 FEET
OVER THE NEXT DAY OR SO WITH GENTLE TO MODERATE NORTHEAST WINDS
EXPECTED. A MODERATE RISK OF RIP CURRENTS ALONG NORTH AND EAST FACING
REEFS AND LOW RISK ALONG SOUTH AND WEST FACING REEFS CONTINUES, WITH
PRIMARY SWELL FROM THE NORTH TO NORTHEAST. THE MARINE AND SURF
FORECASTS REMAIN WELL ON TRACK WITH VERY LITTLE CHANGE. A BUILDING
TRADE-WIND SURGE IS EXPECTED TO LEAD TO AN INCREASE IN WINDS AND
SEAS THIS WEEKEND, POTENTIALLY GENERATING CONDITIONS HAZARDOUS TO
SMALL CRAFT STARTING AROUND LATE SUNDAY NIGHT OR MONDAY. THIS WILL
LIKELY ALSO BRING A HIGH RISK OF RIP CURRENTS ALONG EAST-FACING
REEFS, AND POTENTIALLY ELEVATED SURF FOR NORTH-FACING REEFS.
EASTERN MICRONESIA UPDATE
THERE WAS LITTLE CHANGE TO THE FORECAST. SATELLITE EARLY THIS MORNING
SHOWS WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS OVER AND JUST
EAST OF THE SOUTHERN MARSHALL ISLANDS, ASSOCIATED WITH A WEAK
TROPICAL DISTURBANCE TO THE SOUTH-SOUTHEAST OF MAJURO. A BROAD
TRADE-WIND TROUGH EXTENDS SOUTHWARD INTO THE CIRCULATION PASSING
MAJURO TO THE EAST, AND ANOTHER BROAD TROUGH EXTENDS EAST-SOUTHEAST
ACROSS THE REGION WELL SOUTH OF POHNPEI AND KOSRAE. THESE FEATURES
WILL INCREASE SHOWERS ACROSS EASTERN MICRONESIA THROUGH TONIGHT AS
THE CIRCULATION AND TRADE-WIND TROUGH SHIFT WEST ACROSS THE RMI, AND
CONVERGENCE INCREASES NEAR POHNPEI AND KOSRAE ALONG THE NORTHERN
PERIPHERY OF THE BROAD TROUGH NEARBY. MAJURO IS EXPECTED TO SEE
SCATTERED SHOWERS BUILD TO NUMEROUS TONIGHT, WITH LOCALLY HEAVY
SHOWERS EXPECTED. GUSTS TO 25 KNOTS WERE INCLUDED IN MAJURO'S
FORECAST FOR TONIGHT, NEAR HEAVIER SHOWERS.
WESTERN MICRONESIA UPDATE
THERE WAS LITTLE CHANGE TO THE FORECAST, AS RELATIVELY DRY CONDITIONS
PERSIST FOR PALAU, YAP, AND CHUUK THIS MORNING. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ARE FOCUSED WELL SOUTH OF KOROR AND WEST OF
CHUUK, ASSOCIATED WITH AREAS OF CONVERGENCE WITHIN THE NEAR-
EQUATORIAL TROUGH (NET). MODEL GUIDANCE MAINTAINS SPOTTY SHOWER
COVERAGE ACROSS THE REGION THROUGH TONIGHT AND THE REMAINDER OF THE
WEEK BEFORE A BROAD DISTURBANCE, INTERACTING WITH THE NET, LOOKS TO
BUILD SHOWERS ACROSS CHUUK AROUND LATE SUNDAY AND MONDAY.
PREV DISCUSSION
/ISSUED 621 PM CHST WED APR 1 2026/
MARIANAS SYNOPSIS...
PARTLY CLOUDY SKIES, GENTLE TO MODERATE TRADES, AND ISOLATED SHOWERS
PREVAIL ACROSS THE REGION THIS AFTERNOON. BUOY DATA SHOWS SEAS AROUND
5 TO 8 FEET, WITH THE MAIN SWELL ENERGY OUT OF THE NORTH TO
NORTHEAST.
DISCUSSION...
AFTERNOON SATELLITE IMAGERY SHOWS THAT THE SHEAR LINE FRAGMENT HAS
WEAKENED ACROSS THE CNMI, WITH ONLY SPOTTY SHOWERS ACROSS THE
MARIANAS. A RELATIVELY DRY PATTERN CONTINUES WITH ISOLATED TO LOW-
END SCATTERED SHOWERS EXPECTED OVER THE NEXT SEVERAL DAYS. AN AREA OF
HIGH PRESSURE IS EXPECTED TO MOVE EASTWARD OFF THE COAST OF JAPAN
LATE FRIDAY NIGHT. THE RESULTING PRESSURE GRADIENT BETWEEN THE NEAR-
EQUATORIAL TROUGH TO THE SOUTH WOULD LEAD TO WINDS INCREASING TO
MODERATE TO FRESH STARTING FRIDAY NIGHT OR SATURDAY, POSSIBLY SEEING
BREEZIER CONDITIONS SUNDAY THROUGH MONDAY.
MARINE/SURF...
COMBINED SEAS ARE EXPECTED TO BE 5 TO 7 FEET TONIGHT, DECREASING TO
4 TO 6 FEET LATE THIS WEEK. A TRADE WIND SURGE BEGINS TO DEVELOP
EAST OF THE REGION FRIDAY NIGHT AND OVER THE WEEKEND, RESULTING IN
WINDS INCREASING TO MODERATE TO FRESH ACROSS THE MARIANAS,
POTENTIALLY REACHING HAZARDOUS LEVELS OF 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. MINOR NORTHERLY SWELL ALSO MOVES IN
MONDAY, WHEN SEAS ARE ALSO ANTICIPATED TO REACH HAZARDOUS LEVELS OF
10 FEET. 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 FEW DAYS, WITH PRIMARY SWELL FROM THE NORTH TO NORTHEAST. AN
INCREASE IN EAST-NORTHEAST TRADE WINDS AND SWELL OVER THE WEEKEND
AND THE ARRIVAL OF MINOR NORTHERLY SWELL MONDAY ARE EXPECTED TO BUILD
SURF ALONG EAST AND NORTH FACING REEFS, LIKELY INCREASING THE RIP
RISK TO HIGH FOR EAST- FACING REEFS AND POTENTIALLY PRODUCING
ELEVATED SURF 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.
GENERALLY QUIET CONDITIONS ARE SEEN ACROSS EASTERN MICRONESIA WITH
SOME SCATTERED SHOWERS SEEN ACROSS MAJURO AND ENTERING KOSRAE
COASTAL WATERS. A TROPICAL DISTURBANCE IS CURRENTLY LOCATED NEAR
KIRIBATI. THIS FEATURE IS EXPECTED TO MANEUVER SLOWLY ACROSS EASTERN
MICRONESIA OVER THE NEXT SEVERAL DAYS. HEAVY RAINFALL AND GUSTY WINDS
WILL BE TRACKED OVER THE NEXT SEVERAL DAYS AS THE DISTURBANCE DRIFTS
WESTWARD. ORGANIZATION WITH THIS FEATURE INTO A TROPICAL CYCLONE IS
NOT EXPECTED FOR AT LEAST THE NEXT FEW DAYS. AFTER THE CURRENT LULL
IN ACTIVITY, INFLUENCE FROM THE TROPICAL DISTURBANCE AND THE NEAR
EQUATORIAL TROUGH (NET) IS EXPECTED TO BRING AN UNSETTLED PATTERN TO
THE REGION, STARTING THURSDAY NIGHT AT MAJURO AND BEGINNING TO BUILD
INTO KOSRAE AND POHNPEI AROUND SATURDAY NIGHT OR SUNDAY. DUE TO THE
CURRENT FULL MOON PHASE, THE PACIOOS WAVE RUN-UP FORECAST INDICATES
WAVES MAY NEAR INUNDATION HEIGHT THRESHOLDS FOR MAJURO AT TIMES OF
HIGH TIDE, HOWEVER SIGNIFICANT COASTAL INUNDATION IS NOT EXPECTED
OVER THE NEXT FEW DAYS. ANY POTENTIAL FOR INUNDATION LOOKS TO REMAIN
ISOLATED IN NATURE AND WELL BELOW THE THRESHOLDS FOR A COASTAL FLOOD
STATEMENT.
MARINE CONDITIONS ARE CURRENTLY BENIGN ACROSS THE REGION RANGING
FROM 5 TO 8 FEET. CONDITIONS LOOK TO REMAIN BENIGN FOR MAJURO AND
KOSRAE THROUGH THE NEXT SEVERAL DAYS. A TRADE-WIND SURGE IS EXPECTED
TO SET UP NORTH OF POHNPEI, KOSRAE AND MAJURO LATE THIS WEEK. CHOPPY
SEAS LOOK TO REMAIN NORTH AND WEST OF KOSRAE AND MAJURO, BUT SEAS
COULD BECOME CHOPPY TO POTENTIALLY HAZARDOUS TO SMALL CRAFT THIS
WEEKEND ACROSS POHNPEI. SURF COULD ALSO REACH HAZARDOUS CONDITIONS
FOR NORTH AND WEST FACING REEFS OF POHNPEI THIS WEEKEND.
WESTERN MICRONESIA...
THE MAIN FEATURE IN THE REGION IS A NEAR EQUATORIAL TROUGH (NET)
WITH AN EMBEDDED CIRCULATION. THE NET ENTERS THE REGION NEAR 4N130E
AND EXTENDS EASTWARD ACROSS THE SOUTHERN PORTION OF PALAU AND THROUGH
THE EMBEDDED CIRCULATION NEAR 3N138E (TO THE SOUTH-SOUTHWEST OF YAP
PROPER AND SOUTHEAST OF PALAU). THEN, THE NET CONTINUES TO EXTEND
EASTWARD THROUGH SOUTHERN YAP AND CHUUK STATES WHERE IT CONTINUES
INTO EASTERN MICRONESIA.
PALAU IS NEAR A CONVERGENCE ZONE PRODUCED BY THE CIRCULATION AND THE
PREVAILING NORTHEASTERLY WINDS. SCATTERED SHOWERS ARE BUILDING JUST
OUTSIDE OF PALAU'S COASTAL WATERS. THESE SHOWERS ARE EXPECTED TO
BUILD AS WEAK TROUGHS PASS OVER PALAU. OVER THE NEXT DAY OR SO THE
CIRCULATION IS EXPECTED TO ERODE BACK INTO THE NET. THIS WILL ALLOW
FOR THE A DRIER PATTERN TO SET UP THROUGH THE BEGINNING OF NEXT WEEK.
FOR YAP, A DRIER PATTERN REMAINS OVER THE ISLAND AND IS EXPECTED TO
CONTINUE THROUGH THE BEGINNING OF NEXT WEEK.
FOR CHUUK, THE REMAINS OF 99W PASSED OVER WENO TODAY AND HAS ALL BUT
DISSIPATED. CHUUK IS EXPECTED TO REMAIN FAIRLY DRY OVER THE NEXT
SEVERAL DAYS. THIS IS DUE TO THE NET REMAINING IN THE SOUTHERN
PORTION OF THE STATE. SHOWERS THAT ARE FORMING NEARBY ARE MOVING
SOUTH TO SOUTHEASTWARD AND MISSING CHUUK ALTOGETHER. OVERALL, A DRIER
PATTERN CAN BE EXPECTED, WITH A CAVEAT, SHOWERS MAY INCREASE ACROSS
CHUUK NEAR THE BEGINNING OF NEXT WEEK AS THE DISTURBANCE NEAR
KIRIBATI MOVES CLOSER.
ALTIMETRY SHOWS 3 TO 5 FEET ACROSS THE REGION. THESE SEAS ARE
EXPECTED TO REMAIN FAIRLY STABLE AT PALAU, HOWEVER, YAP AND CHUUK'S
SEAS ARE EXPECTED TO RISE STARTING ON THURSDAY NIGHT FOR YAP AND
FRIDAY FOR CHUUK. COMBINED SEAS AT YAP ARE ANTICIPATED TO BUILD TO
AROUND 5 TO 7 FEET BY THE BEGINNING OF NEXT WEEK AND CHUUK IS
EXPECTED TO BUILD TO 7 TO 9 FEET. THIS IS DUE TO AN INCREASE IN THE
TRADE-WIND SWELL AND A NORTH SWELL MOVING INTO THE REGION. CHUUK MAY
SEE SURF AND SEAS HIGH ENOUGH TO WARRANT HIGH SURF ADVISORY AND A
SMALL CRAFT ADVISORY. WINDS NEAR PALAU ARE EXPECTED TO REMAIN LIGHT
TO GENTLE, WHILE WINDS NEAR YAP EXPECTED TO BE LIGHT TO GENTLE AND
BUILD TO GENTLE TO MODERATE OVER THE REST OF THE WEEK, THEN BUILD
AGAIN TO GENTLE TO FRESH BY EARLY NEXT WEEK. GENTLE TO MODERATE WINDS
NEAR CHUUK ARE EXPECTED TO BUILD TO GENTLE TO FRESH NEAR THE END OF
THE WEEKEND.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS/EAST AND WEST MICRONESIA UPDATE: DECOU
MARIANAS: CRUZ
EAST MICRONESIA: WILLIAMS
WEST MICRONESIA: BOWSHER
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