240
FXPQ50 PGUM 160759
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
559 PM CHST TUE JUN 16 2026
MARIANAS SYNOPSIS
VISIBLE SATELLITE IMAGERY DEPICTS AN AREA OF WEST-MOVING SCATTERED
SHOWERS JUST EAST OF SAIPAN AND TINIAN. BUOY AND ALTIMETRY DATA
SUPPORT COMBINED SEAS OF 3 TO 4 FEET. INVEST 92W CONTINUES TO SHOW
SLOW DEVELOPMENT WITH POSSIBLE TRACKS ANYWHERE FROM S OF GUAM TO NEAR
ANATAHAN LATER THIS WEEK.
DISCUSSION
AN UNSETTLED ATMOSPHERE HAS PRODUCED SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS FOR THE MARIANAS THROUGHOUT THE COURSE OF THE DAY.
GUAM APPEARS TO BE IN A DRYING TREND DUE TO LOWER PRECIPITABLE WATER
(PWAT) VALUES THAN THE CNMI, SO SHOWER COVERAGE IS EXPECTED TO
DIMINISH TO ISOLATED AFTER MIDNIGHT. SCATTERED SHOWERS WILL RETURN IN
THE MORNING DUE TO THE PROXIMITY OF UNSETTLED WEATHER AHEAD OF INVEST
92W. THE CNMI, HOWEVER, WILL REMAIN IN A MOIST ENVIRONMENT WITH
UPPER-LEVEL SUPPORT FOR CONVECTION, SO SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED FOR THE NEXT FEW DAYS AS THE
TROUGH EXTENDING FROM INVEST 92W ORIENTS TO THE NORTHWEST. AS
DISCUSSED IN THE TROPICAL SYSTEMS SECTION BELOW, INVEST 92W REMAINS
UNLIKELY TO PASS THROUGH THE MARIANAS AS A TYPHOON. HOWEVER, THE
MARIANAS SHOULD STILL EXPECT INCREASING SHOWERS, ISOLATED
THUNDERSTORMS, BUILDING SEAS AND SURF, AND STRONGER WINDS. AS
REFLECTED IN THE FORECAST, THESE IMPACTS WILL POSSIBLY REACH THE
REGION AS EARLY AS THURSDAY AFTERNOON AND PEAKING ON FRIDAY.
AFTERWARDS, A RIDGE OF HIGH PRESSURE WILL FILL IN ONCE 92W PASSES,
BRINGING DRIER CONDITIONS TO THE MARIANAS.
MARINE
AS INVEST 92W CONTINUES APPROACHING THE MARIANAS, THE EAST SWELL IS
EXPECTED TO CONTINUE BUILDING, POSSIBLY PEAKING WITH COMBINED SEAS
OF UP TO 6 FT ON FRIDAY. DUE TO THE UNSETTLED PATTERN, THERE IS A
MODERATE RISK OF LIGHTNING FOR THE CNMI, AND A MODERATE RISK OF RIP
CURRENTS ALONG ALL EAST-FACING REEFS THAT WILL CONTINUE THROUGHOUT
THE WEEK. SEAS AND SURF ARE NOT EXPECTED TO REACH ANY HAZARD
CRITERIA AT THIS TIME, HOWEVER, THIS WILL CONTINUE TO BE MONITORED
AS INVEST 92W SLOWLY DEVELOPS.
TROPICAL SYSTEMS
INVEST 92W CONTINUES TO ADVANCE TOWARD THE MARIANAS. 92W IS
CURRENTLY CENTERED NORTH-NORTHWEST OF POHNPEI NEAR 10.1N 157.1E,
MOVING WSW AT AROUND 12 MPH. INVEST 92W REMAINS LOW, MEANING
DEVELOPMENT IS NOT EXPECTED WITHIN THE NEXT 24 HOURS. 92W IS
BEGINNING TO SHOW BETTER ORGANIZATION, WITH INCREASING CONVECTION
NORTHWEST THROUGH EAST OF THE LOW-LEVEL CIRCULATION CENTER (LLCC).
92W WILL CONTINUE TO MOVE WEST TO WEST-NORTHWEST, APPROACHING THE
MARIANAS SOMETIME BETWEEN THURSDAY AFTERNOON AND FRIDAY EVENING.
LATEST MODEL GUIDANCE ARE ALL IN FAIRLY GOOD AGREEMENT THAT INVEST
92W WILL REMAIN FAIRLY WEAK AS IT MOVES THROUGH THE MARIANAS. BASED
ON MODEL GUIDANCE AND LATEST SATELLITE TRENDS, 92W COULD MOVE THROUGH
AS A DISTURBANCE, A TROPICAL DEPRESSION OR POSSIBLY A TROPICAL STORM
(LEAST LIKELY), STRENGTHENING MORE AFTER MOVING WEST OF THE ISLANDS.
MODELS ARE NOT IN VERY GOOD AGREEMENT WITH DIRECTION OF MOVEMENT,
WITH VARIATIONS BEING FROM SOUTH OF GUAM TO NEAR ANATAHAN. STAY TUNED
AS WE MONITOR INVEST 92W FOR SIGNS OF STRENGTHENING FASTER THAN
CURRENTLY EXPECTED.
FOR MORE INFORMATION ON INVEST 92W, SEE BULLETINS ISSUED BY JTWC
UNDER WMO HEADER ABPW10 PGTW.
EASTERN MICRONESIA
THE NEAR-EQUATORIAL TROUGH (NET) IS NOW THE PRIMARY WEATHER PRODUCER
ACROSS EASTERN MICRONESIA AS INVEST 92W MOVES NORTH OF 10N. LATEST
SATELLITE DATA SHOWS MOST OF THE CONVECTION ASSOCIATED WITH THE NET
IS SOUTH OF THE TROUGH, WITH THE NET EAST OF 153E DRIFTING NORTHWARD
OVER THE NEXT FEW DAYS. CURRENTLY, SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED THUNDERSTORMS ARE SEEN SOUTH OF THE TROUGH. AS THE NET
DRIFTS NORTH, THIS CONVECTION IS EXPECTED TO HOLD TOGETHER, BRINGING
INCREASED POPS (PROBABILITY OF PRECIPITATION) TO KOSRAE FIRST ON
WEDNESDAY EVENING, THEN TO POHNPEI THURSDAY, AND FINALLY TO MAJURO
THURSDAY NIGHT. THE NET WILL BE SLOW TO DRIFT NORTH, MAINTAINING POPS
OF 40 PERCENT OR MORE OVER ALL THREE LOCATIONS THROUGH THE WEEKEND.
POHNPEI AND KOSRAE WILL SEE THE HIGHEST POPS, WITH SHOWERS LIKELY
FRIDAY. FOR MAJURO, INCREASING SHOWERS AND ISOLATED THUNDERSTORMS ARE
SEEN TO THE EAST OF THE ATOLL THIS EVENING THAT ARE ASSOCIATED WITH
A BAND OF CONVERGENCE THAT LOOKS TO MOVE INTO THE MARSHALLS WEDNESDAY,
BRINGING LOW-END (POPS OF 30 PERCENT) SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS TO MAJURO WEDNESDAY THROUGH THURSDAY, BEFORE THE NET
AFFECTS THE ATOLL.
MARINE CONDITIONS LOOK TO REMAIN FAIRLY BENIGN, WITH COMBINED SEAS OF
3 TO 5 FEET THROUGH THE WEEKEND AND LIGHT TO GENTLE WINDS.
WESTERN MICRONESIA
DOLDRUM-LIKE CONDITIONS WILL CONTINUE THROUGH THE REST OF THE WEEK
FOR MUCH OF THE REGION. SATELLITE IMAGERY SHOWS ISOLATED SHOWERS NEAR
YAP PROPER. THESE SHOWERS ARE THE PRODUCT OF THE INTERACTION BETWEEN
A UPPER-LEVEL LOW, THE WEAK DOLDRUM ROTATION AND PASSING WEAK TRADE-
WIND TROUGHS.
FOR PALAU, PARTLY CLOUDY SKIES ARE EXPECTED THROUGH THE WEEKEND.
SHOWERS ARE EXPECTED TO BE MINIMAL, ONLY A FEW SHORT-LIVED SHOWERS
ARE EXPECTED THROUGH THE WEEKEND.
TO THE EAST, CHUUK IS SITUATED WITHIN AN AREA OF WEAK TRADE-WIND
CONVERGENCE, AND SATELLITE TRENDS HAVE SHOWN AN INCREASE IN SHOWERS
ACROSS THE AREA THIS AFTERNOON. THIS AGREES WITH LATEST MODEL TRENDS,
AND SHOWERS WERE INCREASED TO HIGH-END ISOLATED (20 PERCENT CHANCE)
IN THE FORECAST FOR CHUUK TONIGHT. A GENERALLY QUIET PATTERN WILL
CONTINUE THROUGH WEDNESDAY, BUT SHOWERS INCREASE TO SCATTERED FROM
WEDNESDAY NIGHT ONWARD FOR CHUUK, AS AN UNSETTLED PATTERN BUILDS IN
FROM THE EAST.
BENIGN SEA CONDITIONS ARE EXPECTED TO CONTINUE. LATEST ALTIMETRY
SHOWS COMBINED SEAS BETWEEN 2 AND 4 FEET ACROSS THE REGION. PALAU AND
YAP WILL CONTINUE TO SEE A LIGHT PRIMARY NORTHEAST TO EAST SWELL
THROUGHOUT THE WEEK. THE PRIMARY SWELL IS FROM THE SOUTHEAST ACROSS
CHUUK, WITH A LIGHT SECONDARY SWELL OUT OF THE EAST-NORTHEAST.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: MESA
EAST MICRONESIA: KLEESCHULTE
WEST MICRONESIA: BOWSHER
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