318
FXPQ50 PGUM 162007
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
607 AM CHST FRI APR 17 2026
MARIANAS UPDATE
OVERALL, CONDITIONS ARE FINALLY BEGINNING TO CLEAR ACROSS THE
MARIANAS. GUAM AND ROTA ARE NO LONGER IN TYPHOON OR TROPICAL STORM
CONDITIONS. TINIAN AND SAIPAN LOOK TO REMAIN IN TS CONDITIONS THROUGH
EARLY THIS MORNING, BEFORE SEEING WINDS FALL BELOW TS CRITERIA AROUND
NOON. SHOWER COVERAGE LOOKS TO BE ISOLATED TODAY WITH THE OCCASIONAL
WEAK RAINBAND POSSIBLE. AS WE HEAD INTO THE WEEKEND AND NEXT WEEK,
CALM WINDS AND DRY CONDITIONS WILL PREVAIL. THIS SHOULD ASSIST IN THE
RECOVERY EFFORTS THAT WILL BE ON THE WAY IN THE WAKE OF TYPHOON
SINLAKU.
DANGEROUS MARINE AND BEACH CONDITONS CONTINUE ACROSS THE MARIANAS.
SEAS WILL BE BETWEEN 12 AND 18 FEET UNTIL THIS AFTERNOON, BUT COULD
PERSIST INTO TONIGHT AND SATURDAY. ALONG WITH HAZARDOUS SEAS GREATER
THAN 15 FEET, DANGEROUS SURF IS ONGOING ACROSS THE MARIANAS. SURF OF
12 TO 18 FEET WILL PRODUCE LARGE POUNDING WAVES. A HIGH SURF WARNING
IS IN EFFECT UNTIL 5 PM TODAY FOR ALL OF THE MARIANAS, BUT MAY NEED
TO BE EXTENDED INTO TONIGHT OR SATURDAY. COASTAL INUNDATION WILL
REMAIN POSSIBLE WITH A COASTAL FLOOD WARNING IN PLACE ACROSS SAIPAN
AND TINIAN FOR 4 TO 6 FEET, AND A COASTAL FLOOD ADVISORY IN PLACE FOR
GUAM AND ROTA FOR 1 TO 2 FEET. COASTAL INUNDATION COULD LINGER INTO
THE WEEKEND AS A NEW MOON EVENT OCCURS.
TROPICAL SYSTEMS UPDATE
AT 500 AM CHST, 1900 UTC, THE CENTER OF TYPHOON SINLAKU WAS LOCATED
NEAR 19.0N, 145.0E, OR 45 MILES WEST-NORTHWEST OF AGRIHAN, AND 270
MILES NORTH OF SAIPAN. TYPHOON SINLAKU HAS WEAKENED INTO A CATEGORY 2
HURRICANE WITH MAXIMUM SUSTAINED WINDS OF 105 MPH. TY SINLAKU IS
CURRENTLY MOVING NORTH-NORTHEAST AT 9 MPH. TY SINLAKU WILL MOVE NORTH
OF AGRIHAN THIS MORNING OR THIS AFTERNOON. WESTERLY TYPHOON WINDS OF
75 TO 95 MPH WILL BE POSSIBLE TODAY. TROPICAL STORM CONDITIONS WILL
CONTINUE ACROSS ALAMAGAN AND PAGAN THROUGH TONIGHT WITH SEVERAL
ROUNDS OF HEAVY RAINFALL EXPECTED. TROPICAL STORM CONDITIONS ARE
EXPECTED TO FALL ACROSS TINIAN AND SAIPAN THIS MORNING.
FOR MORE INFORMATION, PLEASE REFER TO BULLETINS FROM THE JOINT
TYPHOON WARNING CENTER (JTWC) UNDER WMO HEADER WTPN31 PGTW AND FROM
THE NATIONAL WEATHER SERVICE UNDER WMO HEADER WTPQ31 PGUM AND WTPQ81
PGUM.
EASTERN MICRONESIA UPDATE
POHNPEI CAN LOOK FOR ISOLATED SHOWERS THROUGH SATURDAY, THEN
SCATTERED SHOWERS THROUGH TUESDAY. WINDS WILL BE EAST AT 5 TO 10
KNOTS. SEAS OF 5 TO 7 FEET TODAY WILL DIMINISH TO BETWEEN 4 AND 6
FEET TONIGHT THEN PERSIST THROUGH THE REST OF THE FORECAST PERIOD.
THIS WILL LEAD TO BENIGN MARINE CONDITIONS FOR POHNPEI.
IN THE KOSRAE WATERS, EXPECT SCATTERED SHOWERS THROUGH TUESDAY. WINDS
WILL BE EAST TO SOUTHEAST AT 5 TO 15 KNOTS. SEAS OF 5 TO 7 FEET
TODAY WILL BECOME 4 TO 6 FEET TONIGHT THEN PERSIST THROUGH THE REST
OF THE FORECAST PERIOD. THIS WILL LEAD TO BENIGN MARINE CONDITIONS
FOR KOSRAE.
AT MAJURO, THE FORECAST IS FOR ISOLATED SHOWERS TODAY THEN SCATTERED
SHOWERS THROUGH TUESDAY. WINDS WILL BE EAST AT 5 TO 15 KNOTS. SEAS
WILL BE 4 TO 6 FEET THROUGH SATURDAY NIGHT, THEN 3 TO 5 FEET THROUGH
TUESDAY. THIS WILL LEAD TO BENIGN MARINE CONDITIONS FOR MAJURO.
WESTERN MICRONESIA UPDATE
KOROR, PALAU CAN LOOK FOR ISOLATED SHOWER THROUGH THE ENTIRE FORECAST
PERIOD. WINDS WILL BE 5 TO 10 KNOTS, STARTING NORTHWEST AND GRADUALLY
TURNING THROUGH NORTHEAST. SEAS WILL BE 5 TO 7 FEET THROUGH SATURDAY,
THEN 4 TO 6 FEET THROUGH TUESDAY. THIS WILL LEAD TO BENIGN MARINE
CONDITIONS FOR THE KOROR, PALAU WATERS BUT FOR TODAY THERE WILL BE A
LINGERING HIGH SURF ADVISORY.
IN THE YAP WATERS, EXPECT ISOLATED SHOWERS THROUGH THE ENTIRE
FORECAST PERIOD, WITH THE POSSIBLE EXCEPTION OF MONDAY, DURING WHICH
THERE MIGHT BE NONE. WINDS WILL BE 5 TO 15 KNOTS, STARTING FROM THE
NORTHWEST THEN TURNING NORTHEAST. SEAS WILL BE 7 TO 9 FEET THROUGH
SATURDAY, THEN 6 TO 8 FEET THROUGH MONDAY, THEN 5 TO 7 FEET TUESDAY.
THIS WILL LEAD TO CHALLENGING MARINE CONDITIONS THROUGH AT LEAST THE
WEEKEND, WHICH WILL THEN BECOME BENIGN MONDAY OR TUESDAY.
AT CHUUK, THE FORECAST IS FOR ISOLATED SHOWERS THROUGH SUNDAY, THEN
SCATTERED SHOWERS FOR MONDAY AND TUESDAY. WINDS OF 5 TO 15 KNOTS WILL
BEGIN FROM THE SOUTH, THEN TURN THROUGH SOUTHEAST EVENTUALLY REACHING
NORTHEAST. SEAS WILL START AT 5 TO 7 FEET THROUGH SATURDAY NIGHT,
THEN 4 TO 6 FEET THROUGH TUESDAY. THIS WILL LEAD TO BENIGN MARINE
CONDITIONS FOR CHUUK.
PREV DISCUSSION
/ISSUED 605 PM CHST THU APR 16 2026/
MARIANAS SYNOPSIS...
TYPHOON SINLAKU IS SEEN TO THE NORTH OF TINIAN AND SAIPAN, OVER THE
NORTHERN CNMI. MOSTLY CLOUDY TO CLOUDY SKIES WITH ISOLATED SHOWERS
ARE SEEN ACROSS GUAM AND ROTA, WITH CLOUDY SKIES AND NUMEROUS SHOWERS
OVER TINIAN AND SAIPAN WATERS. TANAPAG BUOY SHOWS SEAS BETWEEN 25
AND 28 FEET WHILE ALTIMETRY SHOWS SEAS OF 19 TO 28 FEET OVER THE
MARIANAS, WITH HIGHEST SEAS FOR THE NORTHERN WATERS OF TINIAN AND
SAIPAN.
DISCUSSION...
TYPHOON SINLAKU CONTINUES TO MOVE AWAY FROM THE MARIANAS, PASSING
THROUGH THE NORTHERN CNMI WEST OF ALAMAGAN, PAGAN AND AGRIHAN.
TROPICAL STORM CONDITIONS ARE BEGINNING TO WIND DOWN, WITH THE
TROPICAL STORM WARNING AND TYPHOON WATCH FOR GUAM CANCELLED EARLIER
TODAY. ROTA WILL LIKELY SEE IMPROVED CONDITIONS LATER THIS EVENING.
THE LATEST FORECAST SHOWS TINIAN AND SAIPAN MOVING OUT OF TROPICAL
STORM CONDITIONS AROUND 3 AM. AS THE TYPHOON WARNINGS CLEAR, STRONG
GUSTY WINDS LOOK TO CONTINUE FOR THE NEXT COUPLE OF DAYS. GUAM AND
ROTA WILL SEE A DRY PATTERN DEVELOP, WITH POPS (PROBABILITY OF
PRECIPITATION) FALLING INTO THE 10 TO 20 PERCENT RANGE THROUGH THE
MIDDLE OF NEXT WEEK. TINIAN AND SAIPAN WILL SEE SCATTERED SHOWERS
THROUGH FRIDAY AFTERNOON, THEN THE DRY PATTERN WILL MOVE IN. NICE AND
QUIET WEATHER FOR THE FIRST HALF OF NEXT WEEK, ALLOWING CLEAN UP
FROM SINLAKU TO PROCEED.
MARINE...
ALTHOUGH SINLAKU IS MOVING OUT OF THE AREA AND TROPICAL STORM/TYPHOON
CONDITIONS CONTINUE TO IMPROVE, LARGE SWELL PRODUCING SEAS IN EXCESS
OF 15 FEET WILL CONTINUE INTO THE WEEKEND, PRODUCING HAZARDOUS SEAS
ACROSS THE REGION. A HAZARDOUS SEAS WARNING AND SMALL CRAFT ADVISORY
WERE ISSUED FOR GUAM WATERS EARLIER TODAY AND WILL LIKELY BE ISSUED
FOR ROTA, TINIAN AND SAIPAN AS THE TYPHOON WARNINGS ARE CANCELLED.
SEAS AND WINDS WILL REMAIN ABOVE 10 FEET WELL INTO THE WEEKEND. THE
SEAS WILL MAINTAIN DANGEROUS SURF CONDITIONS INTO THE WEEKEND, ALONG
WITH COASTAL FLOODING THROUGH AT LEAST SATURDAY. MARINE CONDITIONS
LOOK TO FALL BELOW SMALL CRAFT ADVISORY LEVELS LATE IN THE WEEKEND
FOR GUAM AND EARLY NEXT WEEK FOR THE CNMI.
HYDROLOGY...
HEAVY RAINFALL POTENTIAL HAS SUBSIDED AND ALL FLOOD PRODUCTS HAVE
EXPIRED.
TROPICAL SYSTEMS...
AT 500 PM CHST, 0700 UTC, THE CENTER OF TYPHOON SINLAKU WAS LOCATED
NEAR 17.8N, 144.6E, OR 80 MILES WEST OF ALAMAGAN AND AROUND 200
MILES NORTH-NORTHWEST OF TINIAN AND SAIPAN. SINLAKU WAS SLOW TO MOVE
AWAY FROM TINIAN AND SAIPAN FOR MUCH OF THE MORNING, BUT VISIBLE
SATELLITE IMAGERY TRENDS THIS AFTERNOON SHOW THAT THE CENTER OF
SINLAKU'S EYE IS NOW MOVING NORTH-NORTHEAST AS IT PASSES TO THE WEST
OF ALAMAGAN, BEGINNING TO PICK UP FORWARD SPEED MOVING AT ROUGHLY 7
TO 9 MPH. TY SINLAKU REMAINS A POWERFUL CATEGORY 3 STORM WITH MAXIMUM
SUSTAINED WINDS OF AROUND 115 MPH WITHIN THE EYEWALL. SINLAKU IS
FORECAST TO CONTINUE WEAKENING THROUGH THE NEXT FEW DAYS, MAKING A
TURN TOWARD THE NORTHEAST FRIDAY MORNING AS IT PASSES PAGAN AND
AGRIHAN TO THE WEST, THEN TO THE NORTH OF AGRIHAN FRIDAY AFTERNOON.
TINIAN AND SAIPAN ARE EXPECTED TO REMAIN WITHIN THE TROPICAL STORM
FORCE WIND FIELD UNTIL AT LEAST MIDNIGHT TONIGHT, WITH SUSTAINED
WINDS GRADUALLY SUBSIDING BELOW 39 MPH THROUGH THE EARLY MORNING
HOURS OF FRIDAY. THE LATEST FORECAST SHOWS TYPHOON WINDS AROUND 75
MPH DEVELOPING FOR PAGAN AND AGRIHAN LATE TONIGHT BEFORE DEPARTING
AGRIHAN LATE FRIDAY MORNING. TROPICAL STORM CONDITIONS ARE EXPECTED
ACROSS THE NORTHERN CNMI UNTIL LATE FRIDAY NIGHT.
FOR MORE INFORMATION, PLEASE REFER TO BULLETINS FROM THE JOINT
TYPHOON WARNING CENTER (JTWC) UNDER WMO HEADER WTPN31 PGTW AND FROM
THE NATIONAL WEATHER SERVICE UNDER WMO HEADER WTPQ31 PGUM AND WTPQ81
PGUM.
EASTERN MICRONESIA...
AN UNSETTLED PATTERN HAS SET UP FROM THE RMI TO CENTRAL EASTERN
MICRONESIA. THIS IS DUE TO THE REMAINS OF A FRAGMENT OF THE
INTER-TROPICAL CONVERGENCE ZONE (ITCZ) INTERACTING WITH A TRADE-WIND
TROUGH TRAVERSING THE ITCZ. AS SINLAKU MOVES FURTHER AWAY, THIS WILL
ALLOW FOR THE ITCZ FRAGMENT TO MOVE WESTWARD OVER THE COMING DAYS
AND BRING SHOWERS TO KOSRAE AND LINGERING IN RMI. THESE SHOWERS MAY
MOVE INTO POHNPEI AROUND FRIDAY NIGHT AND MONDAY.
ALTIMETRY SHOWS COMBINED SEAS OF 6 TO 7 FEET NEAR POHNPEI AND 4 TO 6
NEAR MAJURO. THERE ARE TWO MIXED SWELLS IN THE REGION AT POHNPEI AND
KOSRAE AND ONE AT MAJURO. THE FIRST IS A MIX OF WEST AND NORTHEAST
SWELLS AND THE OTHER IS A MIX OF EAST AND NORTHEAST SWELLS. WINDS
ARE EXPECTED TO LIGHT TO MODERATE THROUGH THE MIDDLE OF NEXT WEEK.
WESTERN MICRONESIA...
A DRY PATTERN HAS SET UP IN THE WAKE OF TYPHOON SINLAKU. THROUGH THE
MIDDLE OF NEXT WEEK, ISOLATED SHOWERS WITH A FEW PERIODS OF
SCATTERED SHOWERS CAN BE EXPECTED WITH ONE CAVEAT, AROUND MONDAY
SHOWERS AROUND CHUUK MAY BUILD TO AROUND 50 PERCENT CHANCE AS THE
SHOWERS FROM POHNPEI MAY MOVE THROUGH THE REGION.
THE MAIN CONCERNS FOR THE REGION ARE IN THE MARINE REGIONS AROUND YAP
AND KOROR. SWELLS PRODUCED BY SINLAKU ARE KEEPING THE SEAS AND SURF
ELEVATED. AT KOROR, SURF IS EXPECTED TO BE 7 TO 10 FEET ALONG NORTH
FACING REEFS, WHILE AT YAP, SURF IS EXPECTED TO BE 10 TO 14 FEET
ESPECIALLY DURING HIGH TIDE TIMES WITH THE NEW MOON CYCLE ADDING TO
THE SURF HEIGHTS. SEAS NEAR YAP WILL ALSO BE ELEVATED TO ABOVE 10
FEET AND HAZARDOUS TO SMALL CRAFT OPERATIONS. SEAS AND SURF ARE
EXPECTED TO CREST OVER THE EVENING AND EARLY MORNING HOURS, THEN
BEGIN TO FALL AS EARLY AS FRIDAY. CHUUK ON THE OTHER HAND HAS FALLEN
TO JUST BELOW 9 FOOT SURF ALONG WEST AND NORTH FACING REEFS AND IS
EXPECTED TO CONTINUE TO FALL FOR THE NEXT SEVERAL DAYS.
GUM WATCHES/WARNINGS/ADVISORIES
GU...COASTAL FLOOD ADVISORY UNTIL 5 PM CHST SATURDAY FOR GUZ001.
HIGH RIP CURRENT RISK THROUGH SATURDAY AFTERNOON FOR GUZ001.
HIGH SURF WARNING UNTIL 5 PM CHST THIS AFTERNOON FOR GUZ001.
HIGH SURF ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM CHST SATURDAY
FOR GUZ001.
MP...COASTAL FLOOD ADVISORY UNTIL 5 PM CHST SATURDAY FOR MPZ001.
HIGH RIP CURRENT RISK THROUGH SATURDAY AFTERNOON FOR MPZ001>003.
HIGH SURF WARNING UNTIL 5 PM CHST THIS AFTERNOON FOR MPZ001>003.
HIGH SURF ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM CHST SATURDAY
FOR MPZ001>003.
COASTAL FLOOD WARNING UNTIL NOON CHST TODAY FOR MPZ002-003.
TYPHOON WARNING FOR MPZ002-003.
COASTAL FLOOD ADVISORY FROM NOON TODAY TO 5 PM CHST SATURDAY FOR
MPZ002-003.
MARIANAS WATERS...TYPHOON WARNING FOR PMZ153-154.
SMALL CRAFT ADVISORY UNTIL 5 PM CHST SATURDAY FOR PMZ151-152.
HAZARDOUS SEAS WARNING UNTIL 5 PM CHST THIS AFTERNOON FOR PMZ151-
152.
MARIANAS/EAST AND WEST MICRONESIA/TROPICAL UPDATE: WILLIAMS
MARIANAS/EAST AND WEST MICRONESIA/TROPICAL UPDATE: STANKO
MARIANAS: KLEESCHULTE
EAST/WEST MICRONESIA: BOWSHER
TROPICAL: DECOU
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