056
FXPQ50 PGUM 132258
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
858 AM CHST FRI NOV 14 2025
UPDATE
RECENT SATELLITE TRENDS EARLY THIS MORNING SHOWED AN INCREASE IN
CONVECTION ACROSS PALAU, ALONG CONVERGENT TRADES NORTH OF THE NEAR-
EQUATORIAL TROUGH (NET) AND AN EMBEDDED DISTURBANCE NEAR 5N131E.
AIRPORT OBSERVATIONS INDICATED WINDS ROSE TO OVER 20 MPH AS THESE
HEAVIER SHOWERS AND THUNDERSTORMS MOVED THROUGH. UPDATED THE FORECAST
FOR PALAU TO INCREASE POPS TO 60 PERCENT AND INCREASED WINDS TO 5 TO
15 KT WITH OCCASIONAL GUSTS TO 25 KT NEAR HEAVIER CONVECTION THROUGH
THIS AFTERNOON. ALSO TOOK THE OPPORTUNITY TO TAKE POPS DOWN A NOTCH
FOR YAP, TO ISOLATED COVERAGE, SINCE CURRENT SATELLITE SHOWS
SCATTERED SHOWERS HAVE MOVED TO THE SOUTHWEST, WITH ONLY ISOLATED
SHOWERS UPSTREAM.
PREV DISCUSSION
/ISSUED 525 AM CHST FRI NOV 14 2025/
MARIANAS UPDATE...
SATELLITE SHOWS PARTLY CLOUDY SKIES WITH ISOLATED SHOWERS. THE BUOYS
REVEAL COMBINED SEAS OF 4 TO 5 FEET, AND THE KBDI IS LOW AT 124.
THERE'S A SMALL DISTURBANCE TO OUR EAST, WHICH THE FORECAST HAS
COMING IN SATURDAY NIGHT. LOOKS GOOD AT THIS TIME, SO NO CHANGES WERE
MADE. OTHERWISE A RELATIVELY DRY TRADE-WIND FLOW. WELCOME TO WINDER.
IT IS WORTH NOTING THOUGH, THAT THE GEFSWAVE HAD DIALED BACK A BIT ON
ITS EXPECTATIONS FOR THE WIND AND SWELL EVENT NEXT WEEK.
EASTERN MICRONESIA UPDATE...
SHOWERS ARE OVER MAJURO AND BEARING DOWN ON KOSRAE AT THIS TIME. LESS
SHOWER ACTIVITY FOR POHNPEI, CAPTURED AS ISOLATED SHOWERS AT POHNPEI,
WITH SCATTERED FOR KOSRAE AND MAJURO. THIS LOOKS GOOD FOR TODAY, SO
NO CHANGES WERE NEEDED.
WESTERN MICRONESIA UPDATE...
CHUUK IS AT THE FAR NORTHERN EDGE OF THE SHOWERS, AND KOROR, PALAU IS
ON THE NORTH SIDE, ALTHOUGH NOT AS FAR TO THE NORTH AS CHUUK. YAP HAD
AN EXTENSIVE CLOUD BANK EARLIER THAT HAS RECENTLY BEGUN TO ERODE. AT
4 AM, THE FORECAST OF SCATTERED FOR ALL 3, BUT WITH A SLIGHTLY LOWER
POP AT YAP, HAD LOOKED GOOD. WITH THE EROSION OF THAT CLOUD DECK, YAP
MIGHT TURN OUT TO BE ISOLATED TODAY, SO THAT IS THE WEAKEST FORECAST
TODAY. FOR NOW, NO CHANGES WERE MADE.
PREV DISCUSSION... /ISSUED 539 PM CHST THU NOV 13 2025/
MARIANAS SYNOPSIS...
A MINOR TROUGH BROUGHT BY GENTLE TO MODERATE TRADES IS ENTERING
GUAM'S EASTERN WATERS. THE BUOYS SHOW SEAS ARE AROUND 4 TO 5 FEET.
DISCUSSION...
AFTER THE PASSAGE OF A MINOR SURFACE TROUGH THAT WILL BRING LOW-END
SCATTERED SHOWERS TO GUAM LATE TONIGHT, A DRIER TRADE-WIND REGIME
WILL CONTINUE ACROSS THE MARIANAS FOR MUCH OF NEXT WEEK. WINDS ARE
LIKELY TO BEGIN INCREASING INTO THE WEEKEND, POTENTIALLY BECOMING
BREEZY EARLY NEXT WEEK AS THE PRESSURE GRADIENT INCREASES BETWEEN THE
MID-LATITUDES AND THE TROPICS.
MARINE...
COMBINED SEAS OF 4 TO 5 FEET ARE EXPECTED TO PERSIST THROUGH FRIDAY
NIGHT, BEFORE SLOWLY INCREASING THEREAFTER AS TRADE SWELL AND WINDS
PICK UP. A MODERATE RISK OF RIP CURRENTS IS EXPECTED ALONG NORTH
AND EAST FACING REEFS OF THE MARIANAS THROUGH FRIDAY, BEFORE TAPERING
DOWN TO LOW ALONG NORTH FACING REEFS BEGINNING FRIDAY NIGHT. SURF MAY
REBUILD ALONG NORTH AND EAST REEFS BEGINNING EARLY NEXT WEEK AS TRADE
SWELL STRENGTHENS.
EASTERN MICRONESIA...
MODERATE TRADES AND PATCHY SHOWERS ARE SEEN ACROSS MUCH OF THE AREA
THIS EVENING. AFTERNOON SURFACE ANALYSIS SHOWS A WEAK CONVERGENCE
BOUNDARY EXTENDING WEST-EAST BETWEEN POHNPEI AND MAJURO ROUGHLY ALONG
THE AXIS OF PEAK PRECIPITABLE WATER, AS SEEN IN RECENT BLENDED TPW. A
TROUGH IS CURRENTLY PASSING BY THE RATAK CHAIN OF THE RMI AND WILL
CONTINUE WEST THE NEXT COUPLE OF DAYS. IN THE WAKE OF THIS TROUGH,
MODELS SHOW ITCZ CONVECTION FLARING UP BETWEEN 3N AND 8N FROM POHNPEI
EASTWARD. SHOWERS AND THUNDERSTORMS WILL DEVELOP IN WESTWARD-DRIFTING
CLUSTERS FROM TIME TO TIME THROUGH THE WEEKEND. EARLY NEXT WEEK, A
CUTOFF UPPER-LEVEL LOW MAY SET UP OVER THE FAR NORTHERN OR
NORTHWESTERN RMI, POSSIBLY IN A FAVORABLE POSITION TO EXCITE ITCZ
CONVECTION OVER KOSRAE STATE OR PORTIONS OF THE RMI. THIS INTERACTION
COULD BE MANIFEST BY POCKETS OF VERY HEAVY RAINFALL OR BRIEF, BUT
VERY STRONG WIND GUSTS. GIVEN THAT THIS SCENARIO IS STILL 4 DAYS OUT,
WILL WATCH SUBSEQUENT MODEL TRENDS FOR ANY ADJUSTMENTS ON THE UPPER-
LEVEL FEATURES AND TIMING OF CONVECTION.
LATEST ALTIMETRY SHOWS SEAS OF 4 TO 6 FT SOUTH OF 5-6N AND SEAS OF 5
TO 8 FT TO THE NORTH OF 6N AND EAST OF THE MARSHALLS. SEAS WILL
SUBSIDE 1 TO 2 FT THIS WEEKEND BUT WILL THEN INCREASE NEXT WEEK AS A
TRADE-WIND SURGE BUILDS ACROSS THE REGION, ESPECIALLY ALONG AND NORTH
OF 9N. WHILE NO MARINE HAZARDS ARE CURRENTLY ANTICIPATED THROUGH THE
WEEKEND, CONDITIONS WILL STEP CLOSER TO SURF AND SMALL CRAFT HAZARDS
NEXT WEEK. THE POHNPEI BUOY SHOWS A DISTINCT N SWELL IN THE 10-14SEC
PERIOD BAND, AND BASED ON THAT BUOY, HAVE BUMPED UP THE NORTH SWELL
MAGNITUDE A LITTLE ABOVE WAVE MODEL GUIDANCE. ADDITIONALLY, THE
COMBINED SEAS WERE RAISED A LITTLE ABOVE GUIDANCE TO BETTER
INITIALIZE WITH RECENT ALTIMETRY DATA.
WESTERN MICRONESIA...
SATELLITE OBSERVATIONS SHOW ISOLATED SHOWERS ACROSS PALAU AND YAP,
IN ADDITION TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS JUST
OUTSIDE OF THE COASTAL WATERS OF WENO. ALTIMETRY DATA SHOWS COMBINED
SEAS GENERALLY BETWEEN 4 AND 6 FEET ACROSS THE REGION WITH A FEW 7
FOOT SEAS WEST OF WENO.
MUCH QUIETER CONDITIONS ARE PRESENT ACROSS THE REGION TODAY.
ISOLATED SHOWERS ARE CURRENTLY OBSERVED OVER PALAU, YAP, AND WENO.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE SEEN JUST OUTSIDE
OF WENO'S COASTAL WATERS AND ARE EXPECTED TO MOVE INTO WENO THIS
EVENING. SCATTERED SHOWERS WILL PERSIST THE NEXT SEVERAL DAYS ACROSS
CHUUK STATE.
POPS WERE TRENDED DOWNWARD FOR PALAU AND YAP THROUGH THE REST OF THE
WEEK. THE WEAK CIRCULATION THAT WAS INVEST 91W HAS WEAKENED AND THE
JTWC CLOSED 91W EARLY THIS MORNING. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE STILL EXPECTED ACROSS PALAU THROUGH THE WEEK AS
THE NEAR EQUATORIAL TROUGH (NET) CONTINUES TO INTERACT WITH THE WEAK
CIRCULATION SOUTH OF PALAU AND TRADE-WIND CONVERGENCE TO THE EAST.
YAP WILL SEE A BRIEF CHANCE FOR SCATTERED SHOWERS ON FRIDAY WITH
ISOLATED SHOWERS THROUGH THE WEEKEND.
OVERALL, ONLY MINOR EDITS WERE MADE TO THE MARINE FORECAST. BENIGN
SEA CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MONDAY ACROSS
WESTERN MICRONESIA. COMBINED SEAS WILL BE 4 TO 6 FEET THROUGH THE
WEEKEND AND THEN SEAS LOOK TO START INCREASING MONDAY NIGHT INTO
TUESDAY ACROSS CHUUK STATE. THE ECMWF SHOWS A STRONG TRADE-WIND
SWELL MOVE INTO THE REGION TOWARDS THE MIDDLE OF NEXT WEEK. THE GFS
HAS SLIGHTLY LOWER SEA HEIGHTS, BUT HAS TRENDED CLOSER TO THE ECMWF
SOLUTION OVER THE LAST FEW RUNS. THERE WILL BE THE POTENTIAL FOR
HAZARDOUS MARINE AND COASTAL CONDITIONS ACROSS CHUUK TOWARDS THE
MIDDLE OF NEXT WEEK AND YAP TOWARDS THE END OF THE WEEK. THOSE WITH
MARINE INTERESTS IN WESTERN MICRONESIA SHOULD MONITOR FORECASTS FOR
ADDITIONAL DETAILS OVER THE COMING DAYS.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
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