456
FXPQ50 PGUM 251943
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
543 AM CHST SUN APR 26 2026
MARIANAS UPDATE
SATELLITE OBSERVATIONS SHOW PARTLY CLOUDY SKIES ACROSS THE MARIANAS.
BUOY AND ALTIMETRY DATA SHOW COMBINED SEAS BETWEEN 4 AND 6 FEET. NO
CHANGES WERE MADE WITH THIS FORECAST. DRY CONDITIONS LOOK TO CONTINUE
TODAY BEFORE WE SEE A SHIFT TO A SLIGHTLY WETTER PATTERN STARTING
TONIGHT AND PERSISTING THROUGH MONDAY NIGHT. TRADE-WIND CONVERGENCE
ALONG A SHARP TROUGH WILL HELP USHER IN SCATTERED SHOWERS ACROSS THE
MARIANAS. DRY CONDITIONS RETURN TUESDAY AND THROUGH MUCH OF THE
WEEK.
BENIGN SEAS OF 4 TO 6 FEET WILL SLOWLY RISE, PEAKING AROUND 6 TO 8
FEET ON WEDNESDAY. AT THIS TIME, SEAS ARE EXPECTED TO REMAIN BELOW
CONDITIONS HAZARDOUS TO SMALL CRAFT, BUT SURF COULD BECOME HAZARDOUS
ALONG NORTH FACING REEFS WITH A HIGH RISK OF RIP CURRENTS POSSIBLE
ALONG EAST FACING REEFS.
EASTERN MICRONESIA UPDATE
SATELLITE OBSERVATIONS SHOW CONVECTION OVERSPREADING KOSRAE AND
MAJURO THIS MORNING WHILE SHOWERS HAVE HELD OFF AT POHNPEI THIS
MORNING. ALTIMETRY SHOWS COMBINED SEAS BETWEEN 5 AND 7 FEET. LITTLE
TO NO CHANGES WERE MADE TO THE FORECAST. AN ACTIVE PERIOD OF WEATHER
CONTINUES ACROSS EASTERN MICRONESIA AS TWO TROPICAL DISTURBANCES
REMAIN OVER THE REGION. THIS ACTIVE STRETCH LOOKS TO CONTINUE THROUGH
MUCH OF THE WEEK AS A SERIES OF DISTURBANCES MOVE ACROSS THE REGION.
SEAS WILL GENERALLY BE BENIGN OUTSIDE OF SHOWERS WITH COMBINED SEAS
OF 5 TO 8 FEET EXPECTED. CHOPPY SEAS WILL BE POSSIBLE WHERE HEAVIER
SHOWERS OCCUR, WHICH COULD MAKE BOATING DIFFICULT AT TIMES. SURF
WILL ALSO BE ELEVATED ALONG NORTH AND EAST FACING REEFS OVER THE NEXT
FEW DAYS FOR POHNPEI AND KOSRAE.
WESTERN MICRONESIA UPDATE
SATELLITE SHOWS QUIET CONDITIONS ACROSS PALAU AND YAP, AND SHOWERS
AND THUNDERSTORMS JUST EAST OF WENO. ALTIMETRY SHOWS COMBINED SEAS
BETWEEN 4 AND 6 FEET ACROSS THE REGION. NO CHANGES WERE MADE WITH
THIS FORECAST PACKAGE. THE LULL IN SHOWER ACTIVITY AT PALAU AND YAP
WILL PERSIST THROUGH MONDAY NIGHT BEFORE THE NEXT WEATHER SYSTEM
BRINGS SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS TO
YAP AND PALAU. THIS FEATURE IS CURRENTLY IN CHUUK AND WILL CONTINUE
TO BRING SCATTERED SHOWERS THROUGH MUCH OF THE PERIOD.
COMBINED SEAS OF 5 TO 7 FEET WILL GENERALLY REMAIN BENIGN THROUGH THE
PERIOD. SEAS COULD BECOME CHOPPY UNDER HEAVY SHOWERS, MAKING TRAVEL
BY BOAT DIFFICULT AT TIMES.
PREV DISCUSSION
/ISSUED 533 PM CHST SAT APR 25 2026/
MARIANAS SYNOPSIS...
GENTLE TO MODERATE NORTHEASTERLIES PREVAIL ACROSS THE MARIANAS, AS
SATELLITE IMAGERY AND DOPPLER RADAR INDICATE VERY LIGHT PASSING
SHOWERS IN GUAM AND ROTA WATERS. BUOYS INDICATE SEAS ARE 4 TO 5 FEET.
DISCUSSION...
MOSTLY CLEAR SKIES BROUGHT BY A DRY TRADE-WIND REGIME ARE EXPECTED
OVERNIGHT, FOLLOWED BY A SLIGHT INCREASE IN SHOWER COVERAGE UNTIL
LOW-END SCATTERED SHOWERS BROUGHT BY A BROAD TRADE-WIND TROUGH ARRIVE
SUNDAY NIGHT. PATCHY SHOWERS ARE EXPECTED TO LAST THROUGH MONDAY
NIGHT, FOLLOWED BY A RETURN OF DIFFUSIVE TRADES, AS MOST OF THE
CONVECTION REMAINS SOUTH OF THE MARIANAS.
MARINE...
COMBINED SEAS OF 4 TO 6 FEET WILL INCREASE A FOOT OR TWO COMING INTO
NEXT WEEK AS TRADE SWELL AND LOCALIZED WIND WAVES STRENGTHEN. THE
AFOREMENTIONED STRENGTHENING TRADE SWELL AND HIGHER WIND WAVES MAY
PRODUCE A HIGH RISK OF RIP CURRENTS ALONG EAST FACING REEFS BY THE
MIDDLE OF NEXT WEEK, WITH SOME CHANCE OF HAZARDOUS SURF DEVELOPING
ALONG NORTH FACING REEFS.
EASTERN MICRONESIA...
AN INTERTROPICAL CONVERGENCE ZONE (ITCZ) FRAGMENT IS PRODUCING
SCATTERED TO WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ACROSS
KOSRAE AND POHNPEI STATES. GUSTY TRADE SHOWERS ARE ALSO PUSHING
THROUGH THE RMI, WHERE KWAJALEIN RADAR REVEALS OCCASIONAL GUSTS UP
TO 30 KT, HOWEVER, AFTERNOON SATELLITE IMAGERY SHOWS MOST OF THESE
MOVING WEST OF MAJURO. A FRAGMENTED ITCZ PATTERN OVER A DEVELOPING
NEAR-EQUATORIAL TROUGH (NET) PATTERN IN CENTRAL MICRONESIA AND
CONVERGING MODERATE TO FRESH EAST-NORTHEAST TRADES ARE EXPECTED TO
SUPPORT AN UNSETTLED WEATHER PATTERN THROUGH THE REST OF THE WEEKEND
AND MUCH OF THE UPCOMING WEEK. NUMEROUS TO WIDESPREAD LOCALLY HEAVY
SHOWERS CONTINUE AT POHNPEI THROUGH AT LEAST SUNDAY, WITH SCATTERED
TO NUMEROUS LOCALLY HEAVY SHOWERS DEVELOPING AT KOSRAE THROUGH AT
LEAST SUNDAY NIGHT. A NORTHWARD SHIFT IN THIS DEVELOPING PATTERN IS
ALSO EXPECTED TO BRING SCATTERED TO NUMEROUS LOCALLY HEAVY SHOWERS
AND ISOLATED THUNDERSTORMS TO MAJURO FROM SUNDAY THROUGH TUESDAY.
THEN, MODEL GUIDANCE IS SHOWING A POTENTIAL DISTURBANCE BEGINNING TO
DEVELOP AROUND MIDWEEK, NEAR POHNPEI OR KOSRAE. THERE REMAINS SOME
UNCERTAINTY OF THE OVERALL DEVELOPMENT OF THIS FEATURE, SO THIS WILL
CONTINUE TO BE MONITORED IN SUBSEQUENT MODEL RUNS.
GENTLE TO FRESH TRADES WITH OCCASIONAL STRONG GUSTS NEAR HEAVIER
SHOWERS ARE POSSIBLE OVER THE NEXT SEVERAL DAYS. COMBINED SEAS OF 6
TO 8 FEET, SUBSIDE TO 5 TO 7 FEET AROUND TUESDAY, THEN MAY INCREASE
BACK UP TO 6 TO 8 FEET NEAR MAJURO AROUND THURSDAY DUE TO AN INCREASE
IN TRADE WINDS AND SWELL. NORTHERLY SWELL CONTINUES TO CONTRIBUTE TO
ELEVATED SURF ALONG NORTH-FACING REEFS OF POHNPEI AND NORTH- AND
EAST-FACING REEFS OF KOSRAE THROUGH THE WEEKEND.
WESTERN MICRONESIA...
AN UNSETTLED WEATHER PATTERN CONTINUES TO BUILD WESTWARD ACROSS
CHUUK STATE, WITH AN ITCZ FRAGMENT PROPAGATING WEST ALONG THE
NORTHERN PERIPHERY OF A DEVELOPING NET. THE NET EXTENDS ACROSS
CENTRAL MICRONESIA WITH THE AXIS CENTERED WELL SOUTH OF WENO, CHUUK.
HIMAWARI VISIBLE SATELLITE LATE THIS AFTERNOON SHOWS NUMEROUS SHOWERS
EXTENDING ACROSS MUCH OF THE AREA NORTH OF THE NET AXIS, WITH A FEW
ISOLATED THUNDERSTORMS SEEN IN SOME OF THE NEWER CONVECTION TO THE
EAST NEAR POHNPEI. MEANWHILE, SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS CONTINUE MUCH FARTHER WEST, WITHIN AN AREA OF
CONVERGENCE NORTH OF A SERIES OF WEAK TRADE-WIND TROUGHS NOW MOVING
AWAY JUST WEST OF PALAU. PALAU CAN EXPECT SOME DRIER WEATHER TONIGHT
WITH MOSTLY CLEAR CONDITIONS SEEN JUST UPSTREAM. HOWEVER, YAP REMAINS
WITHIN THE EASTERN EXTENT OF THE TRADE-WIND CONVERGENCE THIS
EVENING, WITH SCATTERED SHOWERS EXPECTED TO GRADUALLY DIMINISH
TONIGHT, ESPECIALLY AFTER MIDNIGHT.
THE NET-ITCZ PATTERN NEAR CHUUK WILL GRADUALLY BUILD WESTWARD
THROUGH THE REMAINDER OF THE WEEKEND AND MUCH OF THE COMING WEEK,
PROMOTING UNSETTLED WEATHER ACROSS THE REGION. CURRENT MODEL GUIDANCE
BEGINS TO DEVELOP A CIRCULATION WITHIN THIS PATTERN AROUND MONDAY,
SOMEWHERE OVER SOUTH-CENTRAL YAP STATE NEAR THE EQUATOR. THE
DISORGANIZED CIRCULATION LOOKS TO CONTINUE WESTWARD AND GRADUALLY
SHIFT NORTHWESTWARD, ARRIVING OVER THE REPUBLIC OF PALAU AND YAP
PROPER AROUND MIDWEEK. CURRENTLY, MODELS SHOW VERY SLOW, LIMITED
DEVELOPMENT OF THIS DISTURBANCE, BUT IT IS STILL EXPECTED TO PROVIDE
SOME NUMEROUS, LOCALLY HEAVY SHOWERS OVER PALAU AND YAP AROUND
WEDNESDAY THROUGH THURSDAY.
RECENT ALTIMETRY INDICATES COMBINED SEAS AROUND 3 TO 6 FEET NEAR
PALAU AND 5 TO 7 FEET NEAR YAP AND CHUUK. A PULSE OF NORTH-NORTHEAST
SWELL IS MOVING THROUGH THE REGION, AND LOOKS TO INCREASE SEAS BY A
FOOT OR TWO NEAR PALAU THROUGH THE REMAINDER OF THE WEEKEND. THE
NORTHEAST TRADE SWELL LOOKS TO BUILD EARLY NEXT WEEK OVER CHUUK,
WHICH WILL INCREASE SEAS THERE AND LEAD TO ELEVATED SURF ALONG NORTH
FACING REEFS AROUND TUESDAY.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS/EAST AND WEST MICRONESIA UPDATE: WILLIAMS
MARIANAS: MONTVILA
EAST MICRONESIA: CRUZ
WEST MICRONESIA: DECOU
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page