824
FXPQ50 PGUM 092029
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
629 AM CHST SUN AUG 10 2025
MARIANAS UPDATE
ONLY MINOR EDITS TO THE FORECAST WERE NEEDED TONIGHT. THE MAIN EDITS
WERE TO RECOMBINE THE ZONES AND DELAY THE ONSET OF THE SLIGHTLY
STRONGER EAST SWELL. THIS SWELL IS EXPECTED TO BUILD IN TONIGHT INTO
MONDAY MORNING. TO REFLECT THIS THE SURF WAS GRADUALLY INCREASED TO 5
FEET ALONG EAST FACING REEFS BY MONDAY.
TROPICAL SYSTEMS UPDATE
TROPICAL STORM PODUL IS CENTERED NEAR 21.4N LATITUDE AND 140.4E
LONGITUDE. IT HAS BEEN MOVING WESTWARD AT 9 MPH, WITH MAXIMUM
SUSTAINED WINDS OF 60 MPH. IT IS EXPECTED TO MAINTAIN A WESTWARD
TRACK WHILE SPEEDING UP A LITTLE. PODUL IS EXPECTED TO CONTINUE TO
INTENSIFY, AND COULD BECOME A TYPHOON LATE TONIGHT OR EARLY MONDAY.
FOR MORE INFORMATION ON PODUL, SEE THE BULLETINS FROM THE JOINT
TYPHOON WARNING CENTER UNDER WMO HEADER WTPN32 PGTW, AND FROM WFO
GUAM UNDER WMO HEADER WTPQ32 PGUM.
EASTERN MICRONESIA UPDATE
ONLY MINOR TWEAKS TO POHNPEI'S FORECAST, RAISED THE POP'S 10 PERCENT
TODAY TO 40 AND SCATTERED, AND LOWERED THEM 10 PERCENT TONIGHT TO 20
AND ISOLATED. THIS WAS BASED ON MODEL DATA AND SATELLITE TRENDS. AT
KOSRAE JUST NUDGED AN EAST WIND TODAY TO A SOUTHEAST WIND, AND NO
CHANGES OF ANY NOTE AT MAJURO.
THERE MAY BE SOME 15 KNOT WINDS AT MAJURO ON THURSDAY, OTHERWISE
THOUGH, WINDS WILL BE CAPPED AT 10 KNOTS, AND SEAS WILL BE CAPPED AT
5 FEET. THE BENIGN MARINE CONDITIONS WILL THEREFORE CONTINUE AT LEAST
A FEW MORE DAYS.
WESTERN MICRONESIA UPDATE
THE WIND DIRECTION AT PALAU FOR TODAY GOT TWEAKED FROM EAST TO
NORTHEAST. SAME POP FOR TODAY, BUT IT INCREASED 10 PERCENT TONIGHT.
THE POPS AT YAP WERE WERE LOWERED 20 PERCENT FOR TODAY, SINCE THE
ACTIVITY HAS PRIMARILY DEVELOPED NORTH OF THEM. SIMILAR TO PALAU, THE
WINDS TODAY WERE TWEAKED FROM EAST TO NORTHEAST. THE POPS AT CHUUK
WERE RAISED FOR TODAY BASED ON A DISTURBANCE TO THE WEST GRAZING
THEN, AND A DISTURBANCE TO THE EAST BUILDING IN AS THE DAY
PROGRESSES.
CHUUK HAS BENIGN MARINE CONDITIONS WILL WINDS CAPPED AT 10 KNOTS AND
SEAS CAPPED AT 4 FEET. YAP HAS WINDS CAPPED AT 5 KNOTS AND SEAS
CAPPED AT 3 FEET. PALAU HAS THE CALMEST WATERS OF ALL THOUGH, WITH
WINDS CAPPED AT 5 KNOTS AND WAVES CAPPED AT 2 TO 3 FEET. RIGHT NOW
IT'S A RACE TO THE BOTTOM TO SEE WHO CAN HAVE THE QUIETEST MARINE
FORECAST.
PREV DISCUSSION
/ISSUED 512 PM CHST SAT AUG 9 2025/
MARIANAS SYNOPSIS...
PARTLY CLOUDY SKIES WITH ISOLATED SHOWERS AND LIGHT TO GENTLE TRADE
WINDS PREVAIL ACROSS THE MARIANAS THIS AFTERNOON. ALTIMETRY AND BUOYS
SHOW SEAS OF 2 TO 3 FEET ACROSS THE WATERS, WITH ALTIMETRY SHOWING 2
TO 4 FEET EAST OF THE WATERS.
DISCUSSION...
A FAIRLY DRY TRADE-WIND PATTERN LOOKS TO REMAIN ACROSS THE MARIANAS
FOR THE NEXT SEVERAL DAYS. UPPER-LEVEL DIVERGENCE ASSOCIATED WITH
THE TUTT SHOULD INCREASE CLOUD COVER AND THE RISK OF THUNDERSTORMS
SUNDAY AND SUNDAY NIGHT. FOR GUAM, LIGHT AND VARIABLE WINDS ARE
EXPECTED OVER THE ISLAND TUESDAY. THIS WOULD RESULT IN ISLAND
CONVECTION DURING THE AFTERNOON. LATEST MODEL GUIDANCE SHOWS LIGHT
WINDS CONTINUING THROUGH THURSDAY. MAINTAINED ISOLATED SHOWERS
WEDNESDAY INTO THE WEEKEND FOR NOW, HOWEVER, IF WINDS REMAIN LIGHT,
THE RISK OF ISLAND CONVECTION COULD CONTINUE THROUGH THURSDAY.
MARINE...
LIGHT TO GENTLE WINDS ARE EXPECTED THROUGH NEXT WEEK.COMBINED SEAS
OF 2 TO 3 FEET WILL BUILD SLIGHTLY AS THE TRADE-WIND SWELL INCREASES
BY AROUND 1 FOOT SUNDAY NIGHT. THIS WILL INCREASE SURF ENOUGH ALONG
EAST FACING REEFS TO RAISE THE RIP CURRENT RISK TO MODERATE.
TROPICAL SYSTEMS...
AT 1 PM, TROPICAL STORM PODUL (16W) WAS CENTERED NEAR 22N142E,
MOVING WEST-NORTHWEST AT 7 MPH. TS PODUL IS EXPECTED TO MAKE A SLIGHT
TURN TOWARD THE WEST OVER THE NEXT COUPLE OF DAYS WITH AN INCREASE
IN FORWARD SPEED. PODUL IS EXPECTED TO CONTINUE TO SLOWLY STRENGTHEN,
POSSIBLY BECOMING A TYPHOON SUNDAY AS IT CONTINUES TO MOVE AWAY FROM
THE MARIANAS. FOR MORE INFORMATION ON PODUL, PLEASE REFER TO
BULLETINS ISSUED BY THE JOINT TYPHOON WARNING CENTER UNDER WMO HEADER
WTPN32 PGTW AND FROM THE NATIONAL WEATHER SERVICE UNDER WMO HEADER
WTPQ32 PGUM.
EASTERN MICRONESIA...
SATELLITE OBSERVATIONS SHOW SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ACROSS EASTERN MICRONESIA. ALTIMETRY AND BUOY DATA
SHOW COMBINED SEAS BETWEEN 3 AND 5 FEET WITH SOME 6 FOOT SEAS JUST
EAST OF THE MARSHALL ISLANDS.
THE MAIN CHANGE WITH THIS FORECAST WAS THE INCREASE IN POPS THROUGH
THIS WEEKEND. THE ITCZ HAS BECOME MUCH MORE ACTIVE THIS AFTERNOON
AND IS EXPECTED TO REMAIN ACTIVE THROUGH THE WEEKEND. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED THROUGH SUNDAY NIGHT
FOR POHNPEI, KOSRAE, AND MAJURO, WITH HIGH-END (50%) SCATTERED
SHOWERS EXPECTED FOR MAJURO TONIGHT AND KOSRAE TOMORROW. SHOWERS
WILL BE CAPABLE OF HEAVY RAIN AND GUSTY WIND.
A LULL IN ACTIVITY REMAINS PRESENT FOR THE FIRST HALF OF NEXT WEEK
WITH SHOWER COVERAGE DECREASING TO ISOLATED TO LOW-END SCATTERED
(30%). THIS LULL APPEARS TO BE SHORT-LIVED AS ANOTHER FLEX IN THE
ITCZ LOOKS POSSIBLE LATE NEXT WEEK
MARINE CONDITIONS LOOK TO REMAIN BENIGN THROUGH THE WEEKEND.
COMBINED SEAS OF 3 TO 5 FEET MAY RISE A FOOT OR SO AS A LARGER TRADE
SWELL MOVES INTO THE REGION. CHOPPY SEAS WILL BE POSSIBLE WHERE
HEAVIER SHOWERS OCCUR.
WESTERN MICRONESIA...
SATELLITE IMAGERY AND TODAY'S SCATTEROMETRY ANALYSIS CONTINUES TO
INDICATE PATCHY SHOWERS WITHIN A PATTERN OF LIGHT TO GENTLE WINDS.
WE CONTINUE TO MONITOR A WEAK SOUTH TO SOUTHWEST MONSOON-LIKE PATTERN
OVER THE NEXT FEW DAYS AS TROPICAL STORM PODUL CONTINUES ITS WESTWARD
TRACK, WELL NORTH OF PALAU AND YAP. SOME UNCERTAINTY REMAINS OF THE
EXACT TIMING OF PEAK SHOWERS AND THUNDERSTORMS DUE TO THE WEAK AND
UNORGANIZED PATTERN THAT MODELS ARE PROJECTING, SO REFRAINED FROM
PUTTING IN MENTION OF NUMEROUS SHOWERS FOR PALAU AND YAP, BUT THIS
MAY BE SOMETHING TO CONSIDER IN THE COMING DAYS. STILL, CONTINUE TO
EXPECT A TREND TOWARDS WETTER WEATHER, WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS EXPECTED THROUGH AT LEAST MONDAY NIGHT FOR YAP
AND PALAU. FOR CHUUK, SCATTERED SHOWERS ARE EXPECTED FOR MUCH OF THE
FORECAST PERIOD DUE TO AN INCREASE IN TRADE-WIND CONVERGENCE
OVERNIGHT, TRANSITIONING INTO A BROAD TROUGH WITHIN A SOUTH-
SOUTHEASTERLY FLOW SUNDAY NIGHT AND MONDAY. THEN AROUND THE MIDDLE OF
THE WEEK, A BROAD TRADE-WIND TROUGH IS EXPECTED TO MOVE THROUGH
CHUUK STATE AND MOVE INTO FAR WESTERN MICRONESIA LATE WEEK, BRINGING
ANOTHER UPTICK IN SHOWERS.
BENIGN MARINE CONDITIONS CONTINUE OVER THE NEXT SEVERAL DAYS. BUOY
AND ALTIMETRY DATA SHOW SEAS AROUND 2 TO 3 FEET NEAR PALAU AND YAP
AND UP TO 4 FEET NEAR CHUUK. WINDS ARE EXPECTED TO REMAIN LIGHT TO
GENTLE, VARIABLE AT TIMES.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS UPDATE: BOWSHER
EAST/WEST MICRONESIA UPDATE: STANKO
MARIANAS/TROPICAL: KLEESCHULTE
EAST MICRONESIA: WILLIAMS
WEST MICRONESIA: CRUZ
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