785
FXPQ50 PGUM 061923
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
523 AM CHST THU MAY 7 2026
MARIANAS UPDATE
ONLY A FEW UPDATES WERE NEEDED TO THE FORECAST LAST NIGHT. WEATHER
WISE SCATTERED SHOWERS ARE EXPECTED FOR THE MARIANAS, SHOWERS ARE
EXPECTED TO LINGER OVER GUAM AND ROTA TONIGHT WHILE SHOWERS ARE
EXPECTED TO DIMINISH OVER TINIAN AND SAIPAN. OVER THE NIGHT, BOTH
IPAN BUOY AND TANAPAG BUOY SHOW CONDITIONS (10 FEET AT 10 SEC AT IPAN
AND 8.5 FEET AT 10.5 SEC AT TANAPAG) THAT WOULD WARRANT A HIGH SURF
ADVISORY ALONG EAST AND NORTH FACING REEFS. THESE CONDITIONS ARE ALSO
PRODUCING HIGH RISK OF RIP CURRENTS ALONG NORTH FACING REEFS. TO
REFLECT THIS, THE ADVISORY WAS UPDATED.
TROPICAL SYSTEMS
AT 400 AM CHST, 1800 UTC, THE CENTER OF TROPICAL STORM HAGUPIT (05W)
WAS LOCATED NEAR LATITUDE 7.3N, 144.7E. HIMAWARI INFRARED SATELLITE
IN COHESION WITH THE SCATTEROMETRY, SHOWS THAT THE CIRCULATIONS
ASSOCIATED WITH TS HAGUPIT REMAINS ELONGATED. THE CONVECTIVE PATTERN
IS THAT OF A SHEARED TC WHICH, FAVORS A MORE EASTERLY WINDS. TS
HAGUPIT REMAINS AT 40 MPH SUSTAINED WINDS, WHICH IS NOW EXPECTED TO
PERSIST THROUGH TODAY BEFORE SLIGHTLY INTENSIFYING ON FRIDAY. HAGUPIT
IS MOVING WEST-SOUTHWEST AT 14 MPH. IT IS EXPECTED TO MAKE A SLIGHT
TURN TOWARD THE WEST TONIGHT, BEFORE SHIFTING TOWARD THE WEST-
NORTHWEST. HAGUPIT IS FORECAST TO MAINTAIN THIS INTENSITY TONIGHT,
THEN STRENGTHEN THURSDAY AND THURSDAY NIGHT, POSSIBLY BECOMING A
STRONG TROPICAL STORM BY FRIDAY. TROPICAL STORM FORCE WINDS EXTEND
OUTWARD FROM THE CENTER UP TO 100 MILES TO THE NORTHEAST.
FOR MORE INFORMATION ON TROPICAL STORM HAGUPIT, PLEASE REFER TO
BULLETINS FROM THE JOINT TYPHOON WARNING CENTER UNDER WMO HEADER
WTPN31 PGTW AND FROM THE NATIONAL WEATHER SERVICE UNDER WMO HEADER
WTPQ31 PGUM.
EASTERN MICRONESIA UPDATE
ONLY MINOR EDITS WERE NEEDED TO THE FORECAST TONIGHT. AN UNSETTLE
PATTERN IS EXPECTED TO CONTINUE OVER THE NEXT FEW DAYS AS THE REMAINS
OF INVEST 94W INTERACTS WITH THE INTERTROPICAL CONVERGENCE ZONE
(ITCZ). THIS INTERACTION WILL BRING THE MOST SHOWERS TO POHNPEI AND
KOSRAE, THEN LATER MAJURO. THE MAIN CHANGES WERE IN THE DIRECTION OF
THE PRIMARY SWELL FOR TODAY AND A HEADLINE FOR KOSRAE FOR TONIGHT.
SURF IS EXPECTED TO REMAIN NEAR THRESHOLDS OF HIGH SURF ALONG NORTH
AND EAST FACING REEFS AT BOTH POHNPEI AND KOSRAE.
WESTERN MICRONESIA UPDATE
SATELLITE IMAGERY SHOWS A VERY ACTIVE PATTERN ACROSS CHUUK AND YAP
STATES, WITH LITTLE SHOWER ACTIVITY ACROSS PALAU. COMBINED SEAS ARE
GENERALLY BETWEEN 5 AND 7 FEET ACROSS PALAU, YAP PROPER, AND WENO.
HOWEVER, COMBINED SEAS ARE BETWEEN 10 AND 16 FEET ACROSS EASTERN YAP
STATE AND WESTERN CHUUK STATE NEAR TROPICAL STORM HAGUPIT.
OVERALL, ONLY SLIGHT ADJUSTMENTS WERE MADE WITH THIS FORECAST
PACKAGE. THE MAIN ONE WAS TO ADJUST WINDS DOWN SLIGHTLY, ALIGNING
WITH THE JTWC FORECAST THAT KEEPS TROPICAL STORM HAGUPIT BELOW 50
KNOTS. OTHERWISE, THE FORECAST REMAINS STEADY. TS HAGUPIT WILL
IMPACT FARAULAP AND WOLEAI LATER TODAY BEFORE MOVING TOWARDS
FAIS, ULITHI, YAP PROPER, AND NGULU ON FRIDAY.
MARINE CONDITIONS WILL GENERALLY BE BENIGN THROUGH FRIDAY NIGHT FOR
PALAU AND WENO. FOR YAP, COMBINED SEAS OF 10 TO 16 FEET WILL BE
POSSIBLE FRIDAY AND INTO SATURDAY. DANGEROUS SURF OF 10 TO 14 FEET
AND INUNDATION OF 1 TO 2 FEET.
PREV DISCUSSION
/ISSUED 626 PM CHST WED MAY 6 2026/
MARIANAS SYNOPSIS...
RADAR IMAGERY SHOWS ISOLATED SHOWERS WEST OF THE MARIANAS AND OVER
SOUTHERN GUAM COASTAL WATERS. THERE IS ALSO A BROAD AREA OF ISOLATED
TO SCATTERED SHOWERS FURTHER UPSTREAM, ASSOCIATED WITH TRADE-WIND
CONVERGENCE ALONG A SHALLOW TROUGH. BUOY AND ALTIMETRY DATA SHOW
COMBINED SEAS OF 8 TO 10 FEET.
DISCUSSION...
A TRADE-WIND SURGE CONTINUES ACROSS THE REGION, REINFORCED BY THE
PRESSURE GRADIENT BETWEEN TROPICAL STORM HAGUPIT (05W) TO THE SOUTH
AND HIGH PRESSURE TO THE NORTH. SCATTEROMETRY DATA FROM THIS MORNING
DEPICTS A BROAD AREA OF FRESH TO STRONG TRADE WINDS, EXTENDING EAST
OF 145E TO ROUGHLY 155E, FROM AROUND 10N TO 20N. WIND SPEED
CONVERGENCE IN THE TRADES PRODUCED ISOLATED TO SCATTERED SHOWERS
ACROSS THE MARIANAS THROUGH THE MORNING HOURS, AND MOSTLY QUIET
CONDITIONS PREVAIL THIS EVENING. AS TS HAGUPIT MOVES WEST-NORTHWEST,
GRADUALLY STRENGTHENING OVER THE NEXT FEW DAYS, PERIODS OF LOW-END
SCATTERED SHOWERS ARE EXPECTED FOR GUAM AND ROTA, ASSOCIATED WITH
INCREASED CONVERGENCE INTO THE FAR NORTHERN PERIPHERY OF THE SYSTEM.
A FAIRLY DRY TRADE-WIND PATTERN IS THEN EXPECTED THROUGH THE WEEKEND,
BEFORE THE REGIONAL PRESSURE GRADIENT AND WIND SPEEDS DIMINISH EARLY
NEXT WEEK.
MARINE/SURF...
HIGH PRESSURE NORTH OF THE REGION AND STRENGTHENING TROPICAL STORM
HAGUPIT (05W) TO THE SOUTH WILL BRING MOSTLY FRESH TRADE WINDS
TONIGHT THROUGH THURSDAY AFTERNOON, BEFORE EASING SLIGHTLY TO
MODERATE TO FRESH. THIS WILL MAINTAIN COMBINED SEAS AROUND 8 TO 10
FEET, AND A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH THURSDAY
AFTERNOON. ADDITIONALLY, LIGHT SOUTH-SOUTHWEST SWELL WILL BUILD BY A
FOOT OR TWO THROUGH THURSDAY NIGHT AS TS HAGUPIT STRENGTHENS SOUTH OF
THE MARIANAS. THERE IS A HIGH RISK OF RIP CURRENTS ALONG EAST-
FACING REEFS DUE TO THE ELEVATED TRADE SWELL AND ASSOCIATED SURF,
WHICH IS EXPECTED TO PERSIST INTO THE WEEKEND. THERE IS A MODERATE
RISK ALONG NORTH AND SOUTH-FACING REEFS, IN PART DUE TO THE EFFECTS
OF ISLAND WRAP-AROUND.
TROPICAL SYSTEMS...
AT 400 PM CHST, 0600 UTC, THE CENTER OF TROPICAL STORM HAGUPIT (05W)
WAS LOCATED NEAR LATITUDE 6.9 DEGREES NORTH AND LONGITUDE 145.8
DEGREES EAST. HIMAWARI VISIBLE SATELLITE REVEALS A VERY DISORGANIZED,
LOPSIDED STORM, WITH A BROAD CONVECTIVE COMPLEX LOCATED ALONG ITS
NORTHEASTERN TO EASTERN FLANK WHERE IT INTERACTS WITH THE UPSTREAM
TRADE-WIND FLOW. ALTHOUGH IT STRENGTHENED SLIGHTLY THIS AFTERNOON,
SCATTEROMETRY THIS MORNING DEPICTED A VERY SIMILAR STRUCTURE, WITH
NEAR-GALE WINDS SEEN WITHIN ITS NORTHEAST QUADRANT WITH A NARROW
EMBEDDED AREA OF TROPICAL STORM FORCE WINDS. HAGUPIT IS MOVING WEST-
SOUTHWEST AT 13 MPH. IT IS EXPECTED TO MAKE A SLIGHT TURN TOWARD THE
WEST TONIGHT, BEFORE SHIFTING TOWARD THE WEST-NORTHWEST THURSDAY
WITH A SLIGHT DECREASE IN FORWARD SPEED. MAXIMUM SUSTAINED WINDS
REMAIN AT 40 MPH. HAGUPIT IS FORECAST TO MAINTAIN THIS INTENSITY
TONIGHT, THEN STRENGTHEN THURSDAY AND THURSDAY NIGHT, POSSIBLY
BECOMING A STRONG TROPICAL STORM BY FRIDAY. TROPICAL STORM FORCE
WINDS EXTEND OUTWARD FROM THE CENTER UP TO 100 MILES TO THE
NORTHEAST.
A CIRCULATION IS ALSO SEEN OVER EASTERN MICRONESIA TO THE SOUTH OF
POHNPEI AND KOSRAE, DUBBED INVEST 94W BY THE JOINT TYPHOON WARNING
CENTER (JTWC). 94W REMAINS CATEGORIZED AS A SUB-LOW, MEANING IT IS
NOT EXPECTED TO DEVELOP INTO A SIGNIFICANT TROPICAL CYCLONE OVER THE
NEXT FEW DAYS. MODERATE TO DEEP CONVECTION IS SEEN WITHIN THE
WESTERLIES TO ITS SOUTH, WITH NOTHING ORGANIZED ABOUT THE CENTER.
INVEST 94W REMAINS WEAK, AND MAY BE CLOSED LATER THIS EVENING.
FOR MORE INFORMATION ON TROPICAL STORM HAGUPIT, PLEASE REFER TO
BULLETINS FROM THE JOINT TYPHOON WARNING CENTER UNDER WMO HEADER
WTPN31 PGTW AND FROM THE NATIONAL WEATHER SERVICE UNDER WMO HEADER
WTPQ31 PGUM.
EASTERN MICRONESIA...
INVEST 94W AND AN ENHANCED INTERTROPICAL CONVERGENCE ZONE (ITCZ)
CONTINUE TO BRING AN UNSTABLE WEATHER PATTERN TO THE REGION.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE VISIBLE ON SATELLITE
OVER POHNPEI, KOSRAE, AND MAJURO. SHOWERS ARE EXPECTED TO BECOME
HEAVIER AND MORE WIDESPREAD BY LATE TONIGHT. GUSTY WINDS OF 25 TO 30
KTS ARE POSSIBLE DURING THUNDERSTORMS FOR POHNPEI AND KOSRAE DUE TO
THEIR PROXIMITY TO INVEST 94W. THE WIDESPREAD SHOWERS AND ISOLATED
THUNDERSTORMS ARE EXPECTED TO PERSIST THROUGH AT LEAST FRIDAY AS
INVEST 94W APPEARS LIKELY TO MERGE WITH THE ITCZ AND DISSIPATE. BY
THE WEEKEND, THE ITCZ IS EXPECTED TO DRIFT NORTHWARD AWAY FROM THE
ISLANDS AND WEAKEN, SO RAINFALL COVERAGE IS EXPECTED TO DECREASE,
BRINGING A DRIER REGIME TO POHNPEI, KOSRAE, AND MAJURO EARLY NEXT
WEEK. A PERSISTENT TRADE-WIND PATTERN WILL CONTINUE TO PRODUCE
ELEVATED SEAS AND SURF ALONG EAST AND NORTHEAST WATERS AND EXPOSURES,
BUT NOT QUITE REACH HAZARDOUS SURF LEVELS AT POHNPEI AND KOSRAE.
THE SEAS ARE EXPECTED TO SLOWLY DIMINISH AS THE TRADE SWELL AND
LOCALIZED WIND WAVES WEAKEN OVER THE WEEKEND.
WESTERN MICRONESIA...
A BUSY PATTERN IS NOW IN PLACE ACROSS WESTERN MICRONESIA. AT 1 PM,
TROPICAL STORM HAGUPIT WAS CENTERED NEAR 7N146E, MOVING WEST-
SOUTHWEST THROUGH EASTERN YAP STATE. FOR MORE INFORMATION ON TS
HAGUPIT, SEE THE TROPICAL SYSTEMS SECTION ABOVE. LATEST SATELLITE
IMAGERY SHOWS PARTLY CLOUDY SKIES WITH ISOLATED SHOWERS ACROSS YAP
AND PALAU. FOR WENO, CHUUK, CLOUDY SKIES WITH NUMEROUS LOCALLY HEAVY
SHOWERS AND ISOLATED THUNDERSTORMS PREVAIL.
FOR CHUUK, NUMEROUS LOCALLY HEAVY SHOWERS ARE EXPECTED TO CONTINUE
ACROSS WENO THROUGH TONIGHT. THIS CONVECTION IS FOUND TO THE EAST OF
TS 05W. AS 05W MOVES WEST, CONVECTION WILL DECREASE OVERNIGHT,
BECOMING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BY THURSDAY
MORNING. POPS (PROBABILITY OF PRECIPITATION) LOOK TO REMAIN AROUND
50 PERCENT THROUGH THURSDAY, WITH ISOLATED SHOWERS EXPECTED THURSDAY
NIGHT AS 05W MOVES FAR ENOUGH WEST. LATE IN THE WEEK AND OVER THE
WEEKEND, CONVECTION LOOKS TO AGAIN INCREASE, WITH POPS REACHING UP
TO 40 PERCENT AS THE TRAILING NEAR-EQUATORIAL TROUGH (NET) AND INVEST
94W MOVE CLOSER TO WENO.
FOR YAP AND PALAU, TS HAGUPIT WILL BE THE MAIN WEATHER PRODUCER
FOR THE NEXT FEW DAYS. LATEST FORECAST TRACK FOR TS HAGUPIT HAS THE
STORM MOVING THROUGH JUST SOUTH OF YAP FRIDAY. TROPICAL STORM FORCE
WINDS ARE POSSIBLE AT YAP PROPER AS EARLY AS FRIDAY MORNING. AS
HAGUPIT APPROACHES YAP PROPER, CONVECTION WILL GRADUALLY INCREASE,
WITH SHOWERS BECOMING SCATTERED AT YAP THURSDAY AND PALAU THURSDAY
NIGHT. WIDESPREAD LOCALLY HEAVY SHOWERS ARE EXPECTED AT YAP PROPER
FRIDAY NIGHT INTO SATURDAY. FOR PALAU, THE LATEST TRACK FOR HAGUPIT
KEEPS THE STORM TO THE NORTH, WITH INCREASED CONVECTION REMAINING
OVER PALAU THROUGH THE WEEKEND, WITH POPS OF AROUND 50 PERCENT
THROUGH SATURDAY. BOTH YAP PROPER AND PALAU SHOULD SEE POPS BEGIN TO
DECREASE SUNDAY AND FALLING TO AROUND 20 PERCENT MONDAY.
FOR THE MARINE FORECAST, PALAU AND CHUUK SHOULD SEE SEAS BELOW SMALL
CRAFT ADVISORY LEVELS, HOWEVER, CHOPPY SEAS WILL BE POSSIBLE FOR
CHUUK, ESPECIALLY NEAR HEAVIER SHOWERS AND THUNDERSTORMS DUE TO GUSTY
WINDS. SEAS LOOK TO BE AROUND 6 TO 8 FEET THROUGH THE WEEKEND FOR
CHUUK AND BETWEEN 4 AND 7 FEET AT PALAU. LIGHT TO GENTLE WINDS WILL
PREVAIL AT PALAU, WITH MOSTLY GENTLE TO MODERATE WINDS WITH
OCCASIONAL FRESH WINDS AT WENO. FOR YAP PROPER, SEAS WARE EXPECTED TO
BUILD AS HAGUPIT APPROACHES, POSSIBLY REACHING AS HIGH AS 11 TO 16
FEET. TROPICAL STORM FORCE WINDS ARE POSSIBLE AS EARLY AS FRIDAY
MORNING, AND COULD REACH AS HIGH AS STRONG TROPICAL STORM FORCE
FRIDAY NIGHT.
GUM WATCHES/WARNINGS/ADVISORIES
GU...HIGH RIP CURRENT RISK THROUGH SUNDAY AFTERNOON FOR GUZ001.
HIGH SURF ADVISORY UNTIL 4 PM CHST THIS AFTERNOON FOR GUZ001.
MP...HIGH RIP CURRENT RISK THROUGH SUNDAY AFTERNOON FOR MPZ001>003.
HIGH SURF ADVISORY UNTIL 4 PM CHST THIS AFTERNOON FOR MPZ001>003.
MARIANAS WATERS...SMALL CRAFT ADVISORY UNTIL 5 PM CHST THIS AFTERNOON FOR PMZ151>154.
MARIANAS/EAST MICRONESIA UPDATE: BOWSHER
WEST MICRONESIA/TROPICAL UPDATE: WILLIAMS
MARIANAS/TROPICAL SYSTEMS:DECOU
EAST MICRONESIA: MONTVILA/OGLE WEST
MICRONESIA: KLEESCHULTE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page