423
FXPQ50 PGUM 261939
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
539 AM CHST SAT JUN 27 2026
MARIANAS UPDATE
SHOWER COVERAGE WILL RETURN TO ISOLATED TODAY AND CONTINUE INTO
SUNDAY AS A DRIER TRADE-WIND PATTERN BRIEFLY SETS UP ACROSS THE
MARIANAS. SCATTERED SHOWERS, AND POTENTIALLY ISOLATED THUNDERSTORMS,
WILL LIKELY RETURN SUNDAY NIGHT AS AN UPPER-LEVEL TROUGH PROPAGATES
WESTWARD AND OVER THE REGION. UNCERTAINTY LIES IN WHAT THE STRENGTH
OF THIS TROUGH WILL END UP BEING, SO STAY TUNED! GENTLE TO MODERATE
EAST WINDS WILL CONTINUE THROUGH THE WEEKEND. COMBINED SEAS OF 4 TO 6
FEET WILL SLOWLY DIMINISH THROUGH SUNDAY AS A WEST SWELL AND TRADE
SWELL WEAKEN. A MODERATE RISK OF RIP CURRENTS WILL PERSIST THROUGH
THE WEEKEND ALONG EAST-FACING REEFS.
TROPICAL SYSTEMS UPDATE
INVEST 95W REMAINS RATED AS "LOW" BY THE JOINT TYPHOON WARNING
CENTER (JTWC) THIS MORNING, MEANING DEVELOPMENT INTO A SIGNIFICANT
TROPICAL CYCLONE IS NOT EXPECTED WITHIN THE NEXT 24 HOURS. THE INVEST
IS CURRENTLY LOCATED AROUND 7N174E AND SHOULD GRADUALLY ORGANIZE
THIS WEEKEND INTO EARLY NEXT WEEK AS IT DRIFTS TO THE NORTHWEST. WET
AND UNSETTLED WEATHER CAN BE EXPECTED FOR PORTIONS OF THE NORTHERN
MARSHALL ISLANDS LATE THIS WEEKEND AND INTO EARLY NEXT WEEK AS 95W
TREKS ACROSS THE AREA AS IT SLOWLY DEVELOPS. FOR MORE INFORMATION
PLEASE REFER TO BULLETINS FROM JTWC UNDER WMO HEADER ABPW10 PGTW.
EASTERN MICRONESIA UPDATE
THE NEAR-EQUATORIAL TROUGH (NET) REMAINS DRAPED ACROSS MUCH OF
EASTERN MICRONESIA THIS MORNING. WET AND UNSETTLED WEATHER WILL
CONTINUE AT KOSRAE TODAY AS THE ISLAND REMAINS NEAR THE NET AXIS.
AS A RESULT, NUMEROUS SHOWERS AND ISOLATED THUNDESTORMS CAN BE
EXPECTED AT KOSRAE, WITH LOCALLY HEAVY RAINFALL AND FRESH GUSTS
POSSIBLE IN STRONGER SHOWERS AND THUNDERSTORMS. ISOLATED TO LOW-END
SCATTERED SHOWERS WILL BE POSSIBLE AT MAJURO AND POHNPEI THROUGH
TONIGHT. LIGHT TO GENTLE WINDS WILL PERSIST TODAY AND INTO SUNDAY AT
ALL FORECAST SITES WITH COMBINED SEAS OF 3 TO 5 FEET EXPECTED.
WESTERN MICRONESIA UPDATE
WET AND UNSETTLED WEATHER WILL CONTINUE TODAY FOR PALAU AND YAP WITH
HIGH-END SCATTERED TO NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS
EXPECTED. LOCALLY HEAVY RAINFALL AND FRESH GUSTS WILL BE POSSIBLE
WITH STRONGER SHOWERS AND THUNDERSTORMS, PARTICULARLY AT PALAU.
SHOWERS ARE EXPECTED TO REMAIN GENERALLY ISOLATED IN COVERAGE AT
CHUUK TODAY AND INTO SUNDAY. WINDS WILL REMAIN GENERALLY GENTLE TO
MODERATE THIS WEEKEND, STRONGEST WINDS WILL BE AT PALAU. BENIGN
MARINE CONDITIONS ARE EXPECTED WITH COMBINED SEAS OF 3 TO 5 FORECAST
THIS WEEKEND. THOUGH, LOCALLY CHOPPY SEAS WILL BE POSSIBLE WITH ANY
STRONGER SHOWERS AND THUNDERSTORMS.
PREV DISCUSSION
/ISSUED 601 PM CHST FRI JUN 26 2026/
MARIANAS SYNOPSIS...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM THE TROUGH AND
TRADE WIND SURGE ARE MOVING OUT OF THE REGION LEAVING SCATTERED
SHOWERS TONIGHT, BECOMING ISOLATED BY TOMORROW. COMBINED SEAS HAVE
PEAKED AT 5 TO 7 FEET AND WILL BEGIN TO DECREASE LATE TONIGHT.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE SUNDAY
NIGHT AND POSSIBLY INTO MONDAY.
DISCUSSION...
THE TRAILING END OF TODAY'S TROUGH AND TRADE WIND SURGE WILL HAVE
SCATTERED SHOWERS DIMINISHING OVERNIGHT WITH SLIGHTLY HIGHER RAIN
CHANCES REMAINING FOR GUAM AND ROTA THAN TINIAN AND SAIPAN. WINDS
WILL ALSO DROP BACK DOWN TO MODERATE AND POSSIBLY DECREASE SLOWLY
THROUGHOUT THE WEEK. A DRIER TRADE WIND PATTERN WILL RETURN THIS
WEEKEND UNTIL SUNDAY NIGHT WITH THE ARRIVAL OF SCATTERED SHOWERS AND
POSSIBLY ISOLATED THUNDERSTORMS DEPENDING ON THE STRENGTH OF AN UPPER
LEVEL LOW MOVING INTO THE REGION. IF THE WEAK UPPER LEVEL LOW
SURVIVES, THEN ISOLATED THUNDERSTORMS MAY LAST THROUGH MONDAY AS
MODELS SHOW INCREASING AGREEMENT FOR MODERATE MID-LEVEL SHEAR THAT
WOULD SUPPORT CONVECTION. BY MONDAY NIGHT, THE TRADE WIND PATTERN
LOOKS TO CONTINUE THE REST OF THE WEEK WITH ONLY ISOLATED SHOWERS IN
THE FORECAST.
MARINE...
WINDS AND COMBINED SEAS ARE PEAKING AT MODERATE AND 5 TO 7 FEET
RESPECTIVELY AND WILL SLOWLY DROP THROUGHOUT THE FORECAST PERIOD AS
TRADE WINDS AND THE WEST SWELL FROM DISTANT TROPICAL STORM MEKKHALA
SLOWLY WEAKEN. THERE WILL BE A MODERATE RISK OF RIP CURRENTS ALONG
EAST- AND WEST- FACING REEFS TONIGHT AND THEN EAST-FACING REEFS
THROUGH THE WEEKEND. SCATTERED SHOWERS WILL CONTINUE OVERNIGHT AND
BECOME ISOLATED BY SATURDAY. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE POSSIBLE SUNDAY NIGHT AND POSSIBLY INTO MONDAY.
TROPICAL SYSTEMS...
TROPICAL STORM HIGOS (08W) HAS ACCELERATED NORTHWARD AND HAS EXITED
THE REGION, NEAR 26N134E. MAXIMUM SUSTAINED WINDS HAVE INCREASED TO
65 MPH WITH TROPICAL STORM FORCE WINDS EXTENDING UP TO 60 MILES
OUTWARDS FROM THE CENTER. CONVECTION SURROUNDING HIGOS HAS BECOME
LESS ORGANIZED IN THE LAST 24 HOURS, WITH DENSE CLOUD COVER AND
FLARING DEEP CONVECTION OFFSET TO THE NORTH AND WEST OF THE CENTER.
RELATIVELY DRIER AIR IS WRAPPING IN FROM THE SOUTHWEST, FRAGMENTING
CLOUD BANDS ON THE SOUTHEASTERN PERIPHERY. HIGOS IS STILL FORECAST TO
INTENSIFY SLIGHTLY THROUGH TONIGHT, FOLLOWED BY A WEAKENING PHASE
AND EXTRATROPICAL TRANSITION OVER THE WEEKEND. THE LAST ADVISORY
FROM (TCPPQ2) WAS ISSUED ON HIGOS (08W) EARLIER THIS AFTERNOON.
FOR MORE INFORMATION PLEASE REFER TO BULLETINS FROM THE JOINT
TYPHOON WARNING CENTER (JTWC) UNDER WMO HEADER WTPN32 PGTW AND
FROM THE NATIONAL WEATHER SERVICE UNDER WMO HEADER WTPQ32 PGUM.
INVEST 95W CONTINUES TO BE STILL RATED "LOW" FOR DEVELOPMENT, MEANING
THAT DEVELOPMENT IS POSSIBLE, BUT NOT EXPECTED WITHIN 24 HOURS.
INVEST 95W IS NOW ON THIS SIDE OF THE DATE LINE, LOOSELY ORGANIZED
AROUND 4N178E. EQUATORIAL WESTERLIES SOUTH OF A NEAR-EQUATORIAL
TROUGH CONTINUES TO FEED MOISTURE INTO THE DISTURBANCE, WITH
WIDESPREAD CLOUDS AND SHOWERS SEEN ACROSS NORTHWESTERN KIRIBATI AND
SOUTHERN MARSHALL ISLANDS, WRAPPING INTO INVEST 95W. BROAD SURFACE
TROUGHS EXTEND FROM THE DISTURBANCE TO THE NORTH AND NORTHWEST, ALSO
SPREADING SHOWERS NORTHWARD TO NEAR 11N. FAVORABLE DIFFLUENT FLOW
ALOFT WILL CONTINUE TO SUPPORT SHOWER DEVELOPMENT OVER THE NEXT DAY
OR TWO UNTIL INVEST 95W DRIFTS NORTHWEST TOWARDS THE NORTHERN
MARSHALL ISLANDS. STILL, LATEST MODEL GUIDANCE CONTINUES TO HINT AT
SOME GRADUAL DEVELOPMENT WITH THIS DISTURBANCE OVER THE WEEKEND AND
EARLY NEXT WEEK.
FOR MORE INFORMATION PLEASE REFER TO BULLETINS FROM THE JOINT
TYPHOON WARNING CENTER UNDER WMO HEADER ABPW10 PGTW.
EASTERN MICRONESIA...
AN ACTIVE NEAR-EQUATORIAL TROUGH (NET) EXTENDS ACROSS THE REGION,
LEADING INTO A BROAD TROPICAL DISTURBANCE, INVEST 95W (SEE TROPICAL
SYSTEMS SECTION FOR MORE DETAILS), NEAR 4N178E, ABOUT 460 MILES EAST-
SOUTHEAST OF MAJURO. SCATTERED TO NUMEROUS SHOWERS ARE FOUND ALONG
THE TROUGH, WITH THE DEEPEST CONVECTION SOUTH OF THE NET AXIS, ALONG
MOIST EQUATORIAL WESTERLIES. AS INVEST 95W DRIFTS NORTHWEST TOWARDS
THE NORTHERN MARSHALL ISLANDS, THE NET IS EXPECTED TO TILT NORTH OVER
MAJURO, HOWEVER, A POSSIBLE BUFFER CIRCULATION FORMING OVER THE
WEEKEND MAY INDUCE SOME DIFFLUENT FLOW TO THE SOUTH AND POTENTIALLY
LEADING TO A FRAGMENTED NET PATTERN EARLY NEXT WEEK. POTENTIAL
DEVELOPMENT OF INVEST 95W MAY ALSO SHIFT AND REORGANIZE CONVECTION IN
THE REGION, BRINGING AN INCREASINGLY WET PATTERN ACROSS THE MARSHALL
ISLANDS IN THE COMING DAYS. DUE TO THE PROXIMITY OF THE NET, KOSRAE
WILL ALSO SEE SCATTERED TO NUMEROUS LOCALLY HEAVY SHOWERS THROUGH
SATURDAY, POSSIBLY THROUGH SATURDAY NIGHT. THEN THE BULK OF
CONVECTION MAY SHIFT TO THE EAST, DEPENDING ON THE MOVEMENT AND
DEVELOPMENT OF INVEST 95W. POHNPEI REMAINS SLIGHTLY NORTH OF THE NET,
WITH ONLY ISOLATED TO LOW-END SCATTERED SHOWERS EXPECTED OVER THE
NEXT SEVERAL DAYS.
BENIGN MARINE AND SURF CONDITIONS ARE EXPECTED THROUGH EARLY NEXT
WEEK. LIGHT TO GENTLE WINDS PERSIST THROUGH AT LEAST WEDNESDAY.
ALTIMETRY DATA SHOWS SEAS 4 TO 6 FEET ACROSS THE REGION. A DECREASE
IN NORTHEAST SWELL WILL ALLOW SEAS TO SUBSIDE TO 3 TO 5 FEET OVER
THE WEEKEND. MEANWHILE, LIGHT SOUTHEAST SWELL CONTINUES TO MOVE
ACROSS THE REGION OVER THE NEXT SEVERAL DAYS. LONGER-PERIOD
SOUTHERLY SWELL REACHES MAJURO NEXT WEEK, WHICH MAY BRING A SLIGHT
INCREASE TO SURF ALONG SOUTH-FACING REEFS. LATEST WAVE MODEL GUIDANCE
INDICATES SEAS MAY INCREASE BACK UP TO 6 FEET NEXT WEEK AT MAJURO,
DUE TO THE INCOMING SOUTHERLY SWELL AND AN INCREASE IN SOUTHWESTERLY
WINDS.
WESTERN MICRONESIA...
FOR PALAU AND YAP, A WESTERLY WIND DRIVEN CONVERGENCE IS INTERACTING
WITH THE WESTERN EXTENT OF THE NEAR-EQUATORIAL TROUGH (NET) WITH AN
EMBEDDED CIRCULATION. THIS INTERACTION IS EXPECTED TO BRING
NUMEROUS TO WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS TO BOTH
ISLANDS. MODEL GUIDANCE SUGGESTS THAT THE NET WILL EVENTUALLY OVER
TAKE THE CONVERGENCE. OVERALL A WET PATTERN IS EXPECTED FOR THESE
REGIONS.
FOR CHUUK, MODELS HAVE BACKED OFF ON THE SHOWERS THAT WERE
ANTICIPATED FOR THE REGION, FOR TONIGHT LOW-END SCATTERED SHOWERS ARE
EXPECTED AS A LINE OF SHOWERS PASSES OVER. CHUUK IS ANTICIPATED TO
REMAIN NORTH OF THE NET AND AWAY FROM THE SHOWERS, TO REFLECT THIS
POPS WERE REDUCED TO 20 PERCENT THROUGH THE MIDDLE OF NEXT WEEK.
COMBINED SEAS OF 3 TO 5 FEET ARE EXPECTED THROUGH THE BEGINNING OF
NEXT WEEK. WINDS ARE EXPECTED TO BE LIGHT TO GENTLE. OVERALL BENIGN
SEAS CONDITIONS ARE EXPECT, EXCEPT NEAR HEAVIER SHOWERS.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS/EAST AND WEST MICRONESIA/TROPICAL UPDATE: WHISNANT
MARIANAS: OGLE
EAST MICRONESIA: CRUZ
WEST MICRONESIA: BOWSHER
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