939
FXPQ50 PGUM 091917
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
517 AM CHST SAT JAN 10 2026
MARIANAS UPDATE
NO FORECAST UPDATES WERE NEEDED, AS THE GOING FORECAST LOOKS GOOD.
PARTLY CLOUDY SKIES AND JUST A FEW BRIEF/LIGHT SHOWERS CONTINUE TO
CROSS THE MARIANAS IN THIS DRY TRADE- WIND FLOW. THE RITIDIAN AND
TANAPAG BUOYS ARE NO LONGER TRANSMITTING, AND THE OVERNIGHT ALTIMETRY
DIDN'T COME IN, MAKING ANALYSIS OF SEA HEIGHTS A CHALLENGE. STILL,
TABULAR WAVE DATA FOR RITINIAN SUGGESTS GRADUALLY BUILDING SEAS WILL
CONTINUE FOR THE WEEKEND, WITH RIP RISK AND SURF HEADLINE ISSUANCE IN
FUTURE FORECAST PACKAGES NOT OUT OF THE QUESTION.
EASTERN MICRONESIA UPDATE
NO FORECAST UPDATES WERE NEEDED AS THE FORECAST REMAINS ON TRACK.
DESPITE A DECENT UPPER-LEVEL LOW SITUATED OVER POHNPEI, WHICH IS
MOVING WEST, SOMEWHAT LACK- LUSTER SURFACE CONVERGENCE AND PWATS
(PRECIPITABLE WATER VALUES) OF ~1.3-1.8 INCHES IS ALLOWING FOR ONLY
ISOLATED SHOWER DEVELOPMENT BETWEEN CHUUK AND POHNPEI TO CONTINUE.
WESTERN MICRONESIA UPDATE
NO CHANGES WERE NEEDED THIS FORECAST CYCLE, AS THE CURRENT FORECAST
LOOKS GREAT. IN GENERAL, HIGH SURF CONCERNS REMAIN FOR PALAU AND
YAP, WITH A SMALL CRAFT ADVISORY REMAINING IN PLACE AT YAP, WHERE THE
PRESSURE GRADIENT IS TIGHTER, ALLOWING FOR HIGHER WINDS TO PERSIST.
PREV DISCUSSION
/ISSUED 541 PM CHST FRI JAN 9 2026/
MARIANAS SYNOPSIS...
THERE IS A SMALL CRAFT ADVISORY IN EFFECT.
SATELLITE IMAGERY SHOWS PARTLY CLOUDY TO MOSTLY CLOUDY SKIES, WHILE
RADAR IMAGERY SHOWS A FEW ISOLATED SHOWERS WITHIN THE REGION.
ALTIMETRY SHOWS COMBINED SEAS OF 6 TO 8 FEET AND IPAN BUOY DATA SHOWS
HEIGHTS OF ABOUT 5 TO 6 FEET AND 6 SECOND PERIODS.
DISCUSSION...
THE MARIANA ISLANDS ARE EXPECTED TO REMAIN UNDER THE INFLUENCES OF
THE CONVERGENCE BETWEEN THE TRADE-WINDS AND WINDS MOVING SOUTH FROM
THE MAIN LAND OF ASIA. THIS CONVERGENCE IS PRODUCING 15 TO 25 MPH
WINDS WITH GUSTS TO 30 MPH. WINDS MAY BEGIN TO DIMINISH AS SOON AS
MONDAY. OVERALL, A DRY TRADE-WIND PATTERN IS EXPECTED THROUGH MOST
OF NEXT WEEK.
MARINE/SURF...
MODERATE TO STRONG NORTHEAST WINDS WITH NEAR-GALE GUSTS WILL
CONTINUE THROUGH THE WEEKEND. SEAS WILL BUILD TO 7 TO 9 FEET TONIGHT,
AND WILL CONTINUE TO BUILD TO 8 TO 10 FEET OVER THE WEEKEND. A SMALL
CRAFT ADVISORY DUE TO WINDS OF 22 KNOTS AND SEAS REACHING 10 FEET
HAS BEEN ISSUED FOR THE WEEKEND. SEAS AND WINDS ARE ANTICIPATED TO
FALL BELOW SMALL CRAFT ADVISORY CONDITIONS AROUND SUNDAY NIGHT, AND
CONTINUE TO FALL OVER THE BEGINNING OF NEXT WEEK.
THERE IS A MODERATE RISK OF RIP CURRENTS ALONG WEST, NORTH AND EAST
FACING REEFS. THE PRIMARY SWELL IS EXPECTED TO TRANSITION FROM THE
NORTHEAST TO EAST. THE SECONDARY SWELL IS EXPECTED TO BUILD TOO. THE
EAST FACING REEFS ARE EXPECTED TO BUILD THE MOST, THEN NORTH FACING
REEFS, AND SOME ALONG WEST FACING REEFS. SURF MAY REACH UP TO 11 FEET
ALONG EAST FACING REEFS AND 9 ALONG NORTH AND ALLOWING FOR THE RISK
TO BECOME HIGH ALONG NORTH AND EAST FACING REEFS. SURF MAY START
FALLING AROUND THE BEGINNING OF NEXT WEEK.
EASTERN MICRONESIA...
LATEST SATELLITE DATA SHOWS MOSTLY CLOUDY SKIES WITH SCATTERED
SHOWERS OVER MAJURO AND ISOLATED SHOWERS OVER POHNPEI. PARTLY CLOUDY
SKIES WITH SPOTTY LIGHT SHOWERS IS SEEN OVER KOSRAE. BUOYS AND
ALTIMETRY SHOW SEAS BETWEEN 4 AND 6 FEET.
AN OVERALL DRY PATTERN IS SEEN ACROSS EASTERN MICRONESIA THIS
AFTERNOON. THE ONLY EXCEPTION TO THIS IS MAJURO. A STRONG UPPER-
LEVEL LOW IS SEEN TO THE NORTHWEST OF MAJURO. DIVERGENCE TO THE
SOUTHEAST OF THIS LOW IS PRODUCING LOW-END SCATTERED SHOWERS OVER
MAJURO THIS AFTERNOON. THESE SHOWERS ARE EXPECTED TO DECREASE TO
ISOLATED DURING THE EVENING AS THE INFLUENCE OF THE LOW MOVES
NORTHWEST. MAJURO WILL THEN SEE A DRY PATTERN THROUGH THE WEEKEND.
OTHER THAN AN INCREASE IN THE CHANCE OF THUNDERSTORMS SATURDAY NIGHT
AND SUNDAY, KOSRAE CAN EXPECT DRY CONDITIONS TO CONTINUE THROUGH
SUNDAY. BY SUNDAY NIGHT, MOISTURE CONTENT LOOKS TO INCREASE. THIS IS
SHOWN ON THE CIMSS MIMIC PRECIPITABLE WATER (PWAT) PRODUCT, WITH A
BAND OF HIGHER PWATS SEEN TO THE SOUTH OF MAJURO APPROACHING THE
ISLAND. WITH THE NEAR-EQUATORIAL TROUGH (NET) MEANDERING ACROSS THE
REGION, THIS INCREASE IN PWAT WILL RESULT IN INCREASED CONVECTION AT
KOSRAE. FOR POHNPEI, LOW-END SCATTERED SHOWERS SHOULD MOVE INTO THE
AREA A BIT EARLIER SUNDAY AS THE BAND OF MOISTURE CURRENTLY OVER
MAJURO MOVES OVER THE STATE. THEN ON SUNDAY NIGHT, THE SAME MOISTURE
AND THE NET AFFECTING KOSRAE WILL MAINTAIN CONVECTION AT POHNPEI. ALL
THREE LOCATIONS CAN THEN EXPECT TO SEE PERIODS OF INCREASED POPS
(PROBABILITY OF PRECIPITATION) THROUGH THE MIDDLE OF NEXT WEEK.
NOT MUCH GOING ON IN THE MARINE FORECAST THROUGH THE WEEKEND. CURRENT
BUOYS AND ALTIMETRY DATA SHOW SEAS BETWEEN 4 AND 6 FEET. THIS LOOKS
TO BE THE RULE THROUGH THE WEEKEND. THEN, EARLY NEXT WEEK, A
BUILDING MID-LATITUDE HIGH PRESSURE SYSTEM WILL RESULT IN INCREASING
TRADE-WIND SWELL AND MODERATE TO FRESH WINDS ACROSS THE REGION.
MAJURO CAN EXPECT NEAR-GALE GUSTS WHILE POHNPEI AND KOSRAE CAN
EXPECT STRONG GUSTS. COMBINED SEAS ARE ALSO EXPECTED TO REACH AROUND
10 FEET AT POHNPEI AND KOSRAE BY TUESDAY, AND UP TO 11 FEET AT
MAJURO. THIS WILL BE MONITORED FOR THE NEXT FEW DAYS FOR ANY CHANGES
THAT MAY BE NEEDED.
WESTERN MICRONESIA...
SATELLITE OBSERVATIONS SHOW SCATTERED SHOWERS MOVING INTO PALAU'S
COASTAL WATERS AND ISOLATED SHOWERS ELSEWHERE ACROSS THE REGION.
ALTIMETRY DATA SHOWS COMBINED SEAS OF 5 TO 7 FEET ACROSS THE REGION.
THE FORECAST FOR WESTERN MICRONESIA GENERALLY REMAINS CONSISTENT
WITH ONLY MINOR ADJUSTMENTS FROM THE PREVIOUS PACKAGES. POPS WERE
INCREASED SLIGHTLY FOR PALAU TONIGHT BASED ON SCATTERED SHOWERS SEEN
ON VISIBLE SATELLITE TO THE NORTHEAST AND MOVING SOUTHWEST TOWARDS
PALAU. SHOWERS REMAIN ISOLATED OVER WENO AT THIS TIME, BUT INCREASED
COVERAGE TO SCATTERED IS EXPECTED OVER THE NEXT COUPLE OF HOURS AND
THROUGH THE NIGHT. A BRIEF LULL IN SHOWERS IS EXPECTED ON SATURDAY
BEFORE A GRADUAL INCREASE IN ACTIVITY BEGINS SATURDAY NIGHT. MODEL
GUIDANCE CONTINUES TO DEPICT A CONVERGENCE BETWEEN THE TRADE-WINDS
AND WINDS MOVING SOUTH FROM THE MAIN LAND OF ASIA ARE PRODUCING WINDS
OF 15 TO 20 KT WITH FREQUENT GUSTS TO 30 KT. BROAD CIRCULATION
EMANATING FROM A BUFFER CIRCULATION NEAR THE EQUATOR TO MOVE JUST
SOUTH OF PALAU EARLY NEXT WEEK AND BRING UNSETTLED WEATHER. AT THIS
TIME, ANY ORGANIZATION OF THE SYSTEM LOOKS TO OCCUR WELL WEST OF OUR
REGION. REGARDLESS OF ORGANIZATION, HEAVY RAINFALL WILL BE POSSIBLE
EARLY NEXT WEEK FOR PALAU AND YAP.
MARINE CONDITIONS ARE EXPECTED TO DETERIORATE ACROSS YAP AND PALAU
TONIGHT. A SMALL CRAFT ADVISORY WAS ISSUED FOR YAP TONIGHT THROUGH
EARLY MONDAY MORNING. A HIGH SURF ADVISORY WAS ALSO ISSUED ALONG
NORTH AND EAST FACING REEFS OF PALAU AND YAP BEGINNING EARLY
SATURDAY MORNING AND LASTING THROUGH EARLY MONDAY MORNING. A TRADE-
WIND SURGE ASSOCIATED WITH A DECAYING SHEAR LINE WILL LEAD TO A
RAPID RISE IN COMBINED SEAS OVERNIGHT. STRONG WINDS ARE EXPECTED FOR
YAP WITH FRESH WINDS EXPECTED FOR PALAU. SMALL CRAFT ADVISORY
CONDITIONS COULD BE FELT ACROSS PALAU LATE THIS WEEKEND AS THE SHEAR
LINE MAKES ITS CLOSEST APPROACH BEFORE DECAYING. BOTH THE SMALL
CRAFT ADVISORY AND HIGH SURF ADVISORY MAY NEED TO BE EXTENDED INTO
EARLY NEXT WEEK AS THE ELEVATED WINDS AND SEAS CONTINUE.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...SMALL CRAFT ADVISORY UNTIL 6 AM CHST SUNDAY FOR MPZ001>003.
MARIANAS WATERS...SMALL CRAFT ADVISORY UNTIL 6 AM CHST SUNDAY FOR PMZ151>154.
MARIANAS/EAST AND WEST MICRONESIA UPDATE: DOLL
MARIANAS: BOWSHER
EAST MICRONESIA: KLEESCHULTE
WEST MICRONESIA: WILLIAMS
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