199
FXPQ50 PGUM 271944
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
544 AM CHST SUN JUN 28 2026
MARIANAS UPDATE
MOSTLY ISOLATED SHOWERS ARE EXPECTED TO PREVAIL TODAY ACROSS THE
MARIANAS WITH AN UPTICK IN SHOWER COVERAGE POSSIBLE TONIGHT AS A
PASSING UPPER-LEVEL TROUGH SWEEPS ACROSS THE AREA. ISOLATED
THUNDERSTORMS WILL ALSO BE POSSIBLE TONIGHT AND INTO MONDAY MORNING.
GENTLE TO MODERATE EAST WINDS WILL GRADUALLY EASE TO MOSTLY GENTLE
TONIGHT. COMBINED SEAS AROUND 4 TO 5 FEET WILL CONTINUE TO DIMINISH
TODAY AND DROP ANOTHER FOOT OR SO AS WE HEAD INTO THE WORK WEEK.
TROPICAL SYSTEMS UPDATE
INVEST 95W CONTINUES TO BE 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 DISTURBANCE IS LOCATED AROUND 6N169E AND GRADUAL
DEVELOPMENT IS EXPECTED AS IT DRIFTS NORTHWARD AND THEN TURNS TO THE
NORTHWEST OVER THE COMING DAYS. FOR MORE INFORMATION ON INVEST 95W,
PLEASE REFER TO BULLETINS FROM JTWC UNDER WMO HEADER ABPW10 PGTW.
ANOTHER DISTURBANCE LOCATED WITHIN THE NEAR-EQUATORIAL TROUGH (NET)
WAS OPENED BY JTWC YESTERDAY, INVEST 96W. THE INVEST IS LOCATED
AROUND 10N134E AND CONTINUES TO BE RATED "SUB-LOW" BY JTWC THIS
MORNING, MEANING DEVELOPMENT IS POSSIBLE BUT NOT ANTICIPATED OVER
THE NEXT COUPLE OF DAYS. INVEST 96W IS EXPECTED TO MOVE SLOWLY TO THE
WEST-NORTHWEST TOWARD THE PHILIPPINES.
EASTERN MICRONESIA UPDATE
THE NET, INVEST 95W, AND A WESTERLY WIND BURST WILL BE THE MAIN
WEATHER PRODUCERS OVER THE COMING DAYS. WET AND UNSETTLED WEATHER
WILL LIKELY BEGIN FOR MAJURO STARTING TONIGHT AS INVEST 95W SLOWLY
ORGANIZES IN THE VICINITY. LOCALLY HEAVY SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE POSSIBLE TONIGHT THROUGH TUESDAY FOR MAJURO.
WEST TO SOUTHWEST WINDS AND SWELL CAN BE EXPECTED AT MAJURO STARTING
TONIGHT, WITH THE POTENTIAL FOR COASTAL INUNDATION, INCREASED SURF,
AND WAVE RUN UP POSSIBLE EARLY THIS WEEK ALONG THE SOUTH AND WEST
FACING AREAS OF THE ATOLL. A HEADLINE CONTINUES TO HIGHLIGHT THE
HEAVY RAIN THREAT AND THE INCREASE IN WEST WINDS AND SWELL. PERIODS
OF WET AND UNSETTLED WEATHER WILL CONTINUE AT KOSRAE THROUGH AT LEAST
TODAY AS THE AXIS OF THE NET REMAINS IN THE VICINITY, ALONG WITH AN
EMBEDDED DISTURBANCE ALONG THE NET. SCATTERED TO LOCALLY NUMEROUS
SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED LATER TODAY AT
KOSRAE AFTER A BRIEF LULL EARLY THIS MORNING. SHOWER COVERAGE SHOULD
REMAIN ISOLATED AT POHNPEI INTO THE COMING WORK WEEK. LIGHT TO
GENTLE WINDS WILL CONTINUE AT KOSRAE AND POHNPEI INTO EARLY THIS
WEEK. LIGHT TO GENTLE SOUTHWEST WINDS CAN BE EXPECTED AT MAJURO
STARTING LATER TODAY AND INCREASING TO MODERATE TO POTENTIALLY FRESH
LATE TONIGHT. GENERALLY BENIGN MARINE CONDITIONS ARE EXPECTED AT BOTH
POHNPEI AND KOSRAE OVER THE COMING DAYS WITH COMBINED SEAS OF 3 TO 5
FEET EXPECTED. COMBINED SEAS AT MAJURO WILL BUILD IN RESPONSE TO THE
INCREASING SOUTHWEST WINDS AND SWELL LATER TODAY, POTENTIALLY TO
AROUND 8 FEET BY LATE MONDAY.
WESTERN MICRONESIA UPDATE
INVEST 96W WILL PROMOTE PERIODS OF SCATTERED TO LOCALLY NUMEROUS
SHOWERS AND ISOLATED THUNDERSTORMS AT BOTH PALAU AND YAP OVER THE
NEXT COUPLE OF DAYS AS IT DRIFTS TO THE WEST-NORTHWEST. LOCALLY HEAVY
RAINFALL WILL BE POSSIBLE IN STRONGER SHOWERS AND THUNDERSTORMS,
PARTICULARLY AT PALAU. HAVE MAINTAINED A HEADLINE FOR PALAU TO
HIGHLIGHT THE HEAVY RAIN THREAT THROUGH AT LEAST MONDAY. MOSTLY
ISOLATED SHOWERS ARE EXPECTED TO PREVAIL AT CHUUK. WINDS ARE
ANTICIPATED TO BE LIGHT TO GENTLE, EXCEPT NEAR 96W, WHERE WINDS ARE
EXPECTED TO BE MODERATE WITH GUSTS TO FRESH. OVERALL, BENIGN MARINE
CONDITIONS ARE EXPECTED WITH COMBINED SEAS HOVERING AROUND 3 TO 5
FEET.
PREV DISCUSSION
/ISSUED 614 PM CHST SAT JUN 27 2026/
MARIANAS SYNOPSIS...
SATELLITE AND RADAR IMAGERY SHOWER MOSTLY JUST ISOLATED SHOWERS FOR
THE MARIANAS WITH A SMALL BAND OF SCATTERED SHOWERS THROUGH ROTA.
SHOWERS ARE EXPECTED TO BECOME SCATTERED FOR ALL ISLANDS BY LATE
TONIGHT. SHOWERS LOOK TO CONTINUE WAVERING BETWEEN SCATTERED AND
ISOLATED FOR MUCH OF THE FORECAST PERIOD AS WEAK TRADE WIND TROUGHS
MOVE THROUGH THE AREA. ISOLATED THUNDERSTORMS ARE POSSIBLE LATE
SUNDAY NIGHT AND MONDAY MORNING. COMBINED SEAS OF AROUND 5 FEET
TONIGHT WILL CONTINUE TO GRADUALLY DECREASE.
DISCUSSION...
A REMNANT BAND OF SCATTERED SHOWERS FROM NOW INVEST 96W REMAINS OVER
ROTA WITH ISOLATED SHOWERS FOR THE REST OF THE ISLANDS. SHOWERS WILL
BECOME MORE SCATTERED LATE TONIGHT FOR ALL ISLANDS. MID LEVEL SHEAR
MAY ALLOW SHOWERS TO STAY SCATTERED FOR TINIAN AND SAIPAN THROUGH
TOMORROW MORNING WHILE GUAM AND ROTA BECOME ISOLATED. SCATTERED
SHOWERS AND LOOK TO RETURN LATE SUNDAY NIGHT AND INTO MONDAY.
INCREASED SHEAR AND A WEAK UPPER LEVEL LOW MAY ALLOW FOR ISOLATED
THUNDERSTORMS AS WELL LATE SUNDAY NIGHT THROUGH MONDAY MORNING.
SHOWERS MAY TURN BACK TO ISOLATED MONDAY NIGHT AND WAVER BETWEEN
SCATTERED AND ISOLATED THE REST OF THE WEEK AS WEAK TRADE WIND
TROUGHS MOVE THROUGH THE AREA. HOWEVER CONFIDENCE REMAINS LOW ON THE
TIMING OF EACH WEAK TROUGH.
MARINE...
COMBINED SEAS OF AROUND 5 FEET WILL SLOWLY DIMINISH THIS WEEKEND AND
INTO NEXT WEEK AS THE TRADE SWELL AND A WEST-NORTHWEST SWELL FROM
DISTANT TROPICAL STORM MEKKHALA WEAKEN. THERE WILL BE A MODERATE RISK
OF RIP CURRENTS ALONG EAST-FACING REEFS THROUGH THE WEEKEND. GENTLE
TO MODERATE EAST WINDS WILL PREVAIL THROUGH TOMORROW BEFORE DROPPING
SLIGHTLY TO GENTLE SUNDAY NIGHT. SCATTERED SHOWERS ARE POSSIBLE
TONIGHT AFTER MIDNIGHT. SHOWERS ARE EXPECTED TO BECOME ISOLATED BY
MORNING FOR GUAM AND ROTA AND BY NOON FOR TINIAN AND SAIPAN. ANOTHER
WAVE OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS IS POSSIBLE LATE
SUNDAY NIGHT AND INTO MONDAY.
TROPICAL SYSTEMS...
INVEST 95W, THAT WAS ROUGHLY LOCATED EAST OF THE MARSHALLS, HAS
GRADUALLY MERGED WITH A COUPLE OF NET DISTURBANCES TO THE SOUTHWEST
OVER THE COURSE OF THE DAY, NOW LOCATED CLOSER TO 5N168E. FLARING,
DEEP CONVECTION IS POORLY ORGANIZED AROUND THE TROPICAL DISTURBANCE
AND EXTENDING NORTHEASTWARD ALONG A BROAD SURFACE TROUGH THAT EXTENDS
THROUGH THE MARSHALLS TO AROUND 14N176E. 95W CONTINUES TO BE RATED
"LOW" FOR DEVELOPMENT, MEANING THAT DEVELOPMENT IS POSSIBLE, BUT NOT
EXPECTED WITHIN 24 HOURS. STILL, LATEST MODEL GUIDANCE CONTINUES TO
SHOW GRADUAL DEVELOPMENT WITH THIS DISTURBANCE OVER THE NEXT FEW
DAYS, FURTHER CONSOLIDATING NEAR THE NORTHWESTERN MARSHALLS. A
WESTERLY WIND BURST IS ALSO DEVELOPING ALONG THE EQUATOR WHICH WILL
CONTINUE TO FEED MOISTURE INTO THE DISTURBANCE, ALSO POINTING TO
FURTHER DEVELOPMENT OF INVEST 95W AROUND SUNDAY NIGHT AND MONDAY. FOR
MORE INFORMATION ON INVEST 95W, PLEASE REFER TO BULLETINS FROM THE
JOINT TYPHOON WARNING CENTER (JTWC) UNDER WMO HEADER ABPW10 PGTW.
A TROPICAL DISTURBANCE EMBEDDED WITHIN THE NET IS NOW DESIGNATED
INVEST 96W BY JTWC. 96W IS LOCATED NEAR 10N137E, ABOUT 105 MILES
NORTHWEST OF YAP PROPER. JTWC HAS RATED THIS "SUB-LOW" FOR
DEVELOPMENT, MEANING DEVELOPMENT IS POSSIBLE, BUT NOT EXPECTED OVER
THE NEXT FEW DAYS. 96W IS EXPECTED TO DRIFT WEST-NORTHWESTWARD,
MOVING AWAY FROM YAP AND PASSING NORTH OF PALAU SUNDAY. STILL,
SHOWERS ALONG WEST-SOUTHWESTERLIES IN ITS WAKE ARE EXPECTED MAINTAIN
AN UNSETTLED PATTERN FOR YAP AND PALAU.
EASTERN MICRONESIA...
AN ACTIVE NEAR-EQUATORIAL TROUGH (NET) EXTENDS ACROSS THE REGION,
ANCHORED TO A BROAD TROPICAL DISTURBANCE, INVEST 95W. SATELLITE
TRENDS SHOWED THE AREA OF VORTICITY EAST OF THE MARSHALLS GRADUALLY
MERGING WITH A COUPLE OF NET DISTURBANCES TO THE SOUTHWEST OVER THE
COURSE OF THE DAY, AND THE CENTER OF THE DEVELOPING PATTERN IS CLOSER
TO 5N168E. CONVECTION SURROUNDING THE NET AND INVEST 95W HAS
SHUFFLED AROUND IN THE PAST 24 HOURS. A BUFFER CIRCULATION HAS FORMED
NEAR EQ175E, INDUCING SOME DIFFLUENT FLOW TO THE SOUTHEAST OF THE
MARSHALLS. ADDITIONALLY, A COUPLE OF EMBEDDED NET DISTURBANCES NEAR
KOSRAE IS ALSO STEERING SOME OF THE WESTERLY FLOW, WITH A WESTERLY
WIND BURST DEVELOPING TO THE SOUTH. SCATTEROMETRY DATA EARLIER TODAY
REVEAL WIND SPEEDS UP TO 30 MPH NEAR THE EQUATOR. IN THE COMING DAYS,
INVEST 95W LOOKS TO GRADUALLY ORGANIZE AROUND THE NORTHWESTERN
MARSHALLS. THIS, IN TURN, LOOKS TO BRING AN INCREASINGLY WET PATTERN
ACROSS MAJURO IN THE COMING DAYS. LATEST MODEL GUIDANCE IS BEGINNING
TO SHOW A BETTER SIGNAL FOR LOCALLY HEAVY SHOWERS AND A POTENTIAL
SURGE IN SOUTHWEST WINDS AND SWELL ACROSS MAJURO SUNDAY NIGHT THROUGH
AT TUESDAY. ADDED A PLAIN-TEXT HEADLINE TO HIGHLIGHT THESE IMPACTS.
FOR KOSRAE, SCATTERED TO NUMEROUS LOCALLY HEAVY SHOWERS CONTINUE
THROUGH SUNDAY. THEN THE BULK OF CONVECTION MAY SHIFT TO THE EAST,
DEPENDING ON THE MOVEMENT AND DEVELOPMENT OF INVEST 95W. STILL,
SCATTERED SHOWERS LOOK TO PERSIST EARLY NEXT WEEK. POHNPEI REMAINS
NORTHWEST OF THE NET DISTURBANCES AND LOOKS TO REMAIN ON THE
OUTSKIRTS OF THE DEVELOPING PATTERN. AND SO, ISOLATED TO LOW-END
SCATTERED SHOWERS ARE EXPECTED THROUGH THURSDAY.
ALTIMETRY DATA SHOWS SEAS 4 TO 6 FEET ACROSS THE REGION. BENIGN
MARINE AND SURF CONDITIONS ARE EXPECTED THROUGH EARLY NEXT WEEK FOR
POHNPEI AND KOSRAE. LIGHT TO MODERATE NORTHWEST WINDS AT POHNPEI AND
KOSRAE ARE EXPECTED TO SHIFT MORE WESTERLY AS THE NET MOVES NORTHWARD
THIS UPCOMING WEEK. TRADE-WIND SWELL AND LIGHT SOUTHEAST SWELL
CONTINUES TO MOVE ACROSS THE REGION OVER THE NEXT SEVERAL DAYS. A
SURGE IN WEST TO SOUTHWEST WINDS AND SWELL ASSOCIATED WITH INVEST 95W
MAY INCREASE SEAS UP TO AROUND 8 FEET AT MAJURO AND INCREASE SURF
ALONG SOUTH- AND WEST-FACING REEFS, POTENTIALLY NEARING HAZARDOUS
LEVELS MONDAY AND TUESDAY. STRONGER WEST-SOUTHWEST WINDS ALSO
PRESENTS A SCENARIO WHERE WAVES CAN PILE UP ON AREAS THAT ARE
THAT ARE TYPICALLY THE LEEWARD SIDE OF THE ATOLL IN A TRADE-WIND
REGIME. FOR INSTANCE, THE EASTERN SIDE OF MAJURO WOULD SEE AN
INCREASE IN WAVES ALONG THE LAGOON-SIDE OF THE ATOLL FROM STRONGER
WESTERLIES. PROPERTIES ALONG WEST-TO-SOUTHWEST FACING COASTLINES
MAY SEE MINOR WAVE RUN-UP AND COASTAL INUNDATION.
WESTERN MICRONESIA...
NEWLY FORMED INVEST 96W WILL BE THE MAIN WEATHER FOR PALAU AND YAP.
CURRENT LOCATION OF 96W IS TO THE NORTHWEST OF YAP PROPER NEAR
10N137E. THIS FEATURE IS EXPECTED TO GRADUALLY MOVE WEST-NORTHWEST
OVER THE COMING DAYS. SCATTERED TO NUMEROUS SHOWERS AND ISOLATED
THUNDERSTORMS (SOME OF WHICH MAYBE HEAVY AT TIMES) ARE EXPECTED FOR
PALAU, WHILE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE
EXPECTED FOR YAP PROPER. THE HEAVIEST SHOWERS ARE EXPECTED TO BE IN
THE WESTERLY INFLOW OF THIS SYSTEM WHICH IS EXPECTED TO PASS OVER
PALAU. 1 TO 2 INCHES OF RAIN ARE POSSIBLE WITH LOCALLY HIGHER AMOUNTS
NEAR HEAVIER SHOWERS. ONCE THIS SYSTEM MOVE FURTHER INTO THE
PHILIPPINE SEA, THE NEAR- EQUATORIAL TROUGH (NET) IS EXPECTED TO KEEP
SHOWERS IN THE AREA FOR PALAU, HOWEVER, THE NET IS EXPECTED TO BRING
PERIODS OF SHOWERS FOR YAP.
FOR CHUUK, A FEW SHOWERS ARE SEEN ON SATELLITE IMAGERY AROUND THE
COASTAL WATERS. TO REFLECT THIS, SCATTERED SHOWERS ARE ANTICIPATED
THROUGH MIDNIGHT, THEN ISOLATED SHOWERS FOR THE EARLY MORNING
HOURS. THEN THE FULL EFFECTS OF THE NEARBY COL WITHIN THE NET IS
EXPECTED TO BRING BENIGN WEATHER CONDITIONS THROUGH THE MOST OF NEXT
WEEK.
COMBINED SEAS OF 3 TO 4 FEET ARE EXPECTED THROUGH THE MIDDLE OF NEXT
WEEK, EXCEPT NEAR 96W, WHERE SEAS ARE EXPECTED TO BE AROUND 4 TO 6
FEET. WINDS ARE ANTICIPATED TO BE LIGHT TO GENTLE, EXCEPT NEAR 96W,
WHERE WINDS ARE EXPECTED TO BE MODERATE WITH GUSTS TO FRESH. 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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