829
FXPQ50 PGUM 240901
AFDGUM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
701 PM CHST WED JUN 24 2026
MARIANAS SYNOPSIS
THE TRAILING SOUTHEAST EDGE OF TROPICAL DEPRESSION HIGOS (08W) IS
BRINGING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO THE MARIANAS
THROUGH TONIGHT. A DRYER TRADE WIND PATTERN IS EXPECTED TO MOVE IN BY
TOMORROW MORNING. COMBINED SEAS HAVE DROPPED BACK DOWN TO AROUND 5
FEET.
DISCUSSION
AS TROPICAL DEPRESSION HIGOS (08W) CONTINUES ITS WNW TREK AWAY FROM
THE MARIANAS. CONDITIONS WILL START TO IMPROVE LATE TONIGHT, WITH
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM THE TRAILING
CONVERGENCE AND SOUTHERLY FLOW INTO TD HIGOS BEING REPLACED BY
ISOLATED SHOWERS TOMORROW MORNING. THIS DRYER, MORE STABLE AIR WILL
REMAIN THROUGH THURSDAY NIGHT BEFORE A SURFACE TROUGH AND A POTENTIAL
TRADE-WIND SURGE ENVELOP THE MARIANAS FRIDAY. THIS SYSTEM IS EXPECTED
TO BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THROUGH FRIDAY
NIGHT. ANOTHER DRYER PERIOD IS EXPECTED TO MOVE IN BY THE WEEKEND AND
CONTINUE THROUGH NEXT WEEK. MODELS INDICATE A WEAK UPPER-LEVEL LOW
MAY ALSO SET ITS EYES ON THE MARIANAS AROUND MONDAY, POTENTIALLY
ALLOWING FOR THUNDERSTORM DEVELOPMENT. HOWEVER, SHEAR LOOKS TO REMAIN
LOW AND MOISTURE APPEARS LIMITED SO KEEPING THE FORECAST AS ISOLATED
SHOWERS FOR NOW.
MARINE
COMBINED SEAS HAVE DROPPED BACK DOWN TO AROUND 5 FEET ARE EXPECTED
THROUGH TOMORROW BEFORE POSSIBLY INCREASING FRIDAY WITH THE ARRIVAL
OF A WEAK TRADE WIND SURGE. MODERATE TO FRESH WINDS MAY BECOME
MODERATE FRIDAY BUT WILL OTHERWISE REMAIN STEADY THROUGH THE FORECAST
PERIOD. THERE WILL BE A MODERATE RISK OF RIP CURRENTS ALONG EAST
FACING REEFS OF THE MARIANAS THROUGH THE WEEKEND. THERE WILL BE A
MODERATE RISK OF LIGHTNING TONIGHT AND POSSIBLY FRIDAY. THE WEST
SWELL FROM DISTANT TYPHOON MEKKHALA BUILD IN AND PEAK BY FRIDAY, BUT
REMAINS FAIRLY SMALL.
TROPICAL SYSTEMS
TROPICAL DEPRESSION HIGOS (08W) CONTINUES TO STIFLE THE NUMERICAL
MODELS (GIVING US A CHALLENGE AS FORECASTERS). 12 HOURS AGO, IT
WAS FORECAST TO CONTINUE STRENGTHENING TO 60 KNOTS AND HAD GOOD
POLEWARD OUTFLOW ALOFT IN A FAVORABLE ENVIRONMENT. SIMILAR TO
YESTERDAY (WHEN IT STRENGTHENED FASTER THAN EXPECTED AND DEVIATED
~100 MILES SOUTH OF THE MEAN ENSEMBLE FORECAST TRACK), IT
CONTINUES TO "DO WHAT IT WANTS", HAVING WEAKENED TO A DEPRESSION
OVERNIGHT, WITH THE CENTER ALSO HAVING TO BE REPOSITIONED. NOW, A
CONVECTIVE BLOSSOM HAS COMMENCED WITH GOOD POLEWARD OUTFLOW ALOFT
AND RAPID CLOUD TOP COOLING, INDICATING IT'S STRENGTHENING AGAIN,
AS FORECAST. WHAT WILL IT DO NEXT? WELL, WE EXPECT IT TO GRADUALLY
STRENGTHEN WHILE MAINTAINING CURRENT MOVEMENT OF WEST AT 10 MPH,
WITH A TURN MORE TO THE WEST-NORTHWEST OR NORTHWEST EXPECTED OVER THE
NEXT FEW DAYS, AS IT CROSSES THE OPEN PHILIPPINE SEA.
FARTHER SOUTHEAST, AN AREA OF DISTURBED WEATHER EAST-SOUTHEAST OF
MAJURO, INVEST 95W (CURRENTLY RATED AS "SUB-LOW", MEANING
TROPICAL CYCLONE DEVELOPMENT MAY OCCUR, BUT WELL BEYOND 24 HOURS)
HAS FORMED AT 5N178E. HERE, WIDESPREAD CONVECTION, SOME LOCALLY
INTENSE AS EVIDENT BY CLOUD TOP TEMPERATURES SURPASSING -80 DEG.
C, BETWEEN THE EQUATOR AND 10N. ALL MODEL GUIDANCE (GEFS, ECENS, AND
GOOGLE DEEPMIND ESPECIALLY), LIFT THE DISTURBANCE SLOWLY NORTHWEST
THROUGH THE RMI DURING THE FIRST HALF OF NEXT WEEK, BEFORE A MORE
WESTERLY TRACK COMMENCES. HOWEVER, THIS IS STILL WAY TO EARLY TO SAY
WHERE IT'LL GO, WHEN, AND AT WHAT STRENGTH. NORMALLY, WE WOULDN'T
MENTION IT YET AS IT'S A DAY 6-8 FORECAST RANGE. WITH THAT SAID, IT'S
BEEN FORECAST WITH THIS GENERAL THEME EVERY MODEL RUN FOR DAYS NOW.
ADDITIONALLY, THE ATMOSPHERE IN THIS REGION IS CONDUCIVE FOR FURTHER
DEVELOPMENT BY THIS TIME, AS THE MJO (MADDEN- JULIAN OSCILLATION)
MOVES INTO A FAVORABLE POSITION, WHICH WOULD LIKELY AID IN ITS
DEVELOPMENT. STAY TUNED!
FOR MORE INFORMATION PLEASE REFER TO BULLETINS FROM THE JOINT
TYPHOON WARNING CENTER UNDER WMO HEADER WTPN32 PGTW AND FROM
THE NATIONAL WEATHER SERVICE UNDER WMO HEADER WTPQ32 PGUM.
EASTERN MICRONESIA
MAJURO:
THE MAIN FOCUS WAS ON INCREASING RAINFALL COVERAGE TO NUMEROUS
SHOWERS, WHICH WE DID WITH THE MORNING UPDATE AND THEN CARRIED THEM
INTO THURSDAY. RAINFALL COVERAGE COULD INCREASE TO NUMEROUS OR
WIDESPREAD SHOWERS WITH LATER FORECASTS, DEPENDENT ON HOW THINGS
UNFOLD WITH INVEST 95W, WHICH IS CURRENTLY IN THE INITIAL STAGES OF A
SLOW DEVELOPMENT. MARINERS CAN EXPECT LIGHT TO OCCASIONALLY MODERATE
WINDS, WITH SEAS OF 4 TO 6 FEET. FOR MORE INFORMATION ON 95W, PLEASE
REFERENCE THE TROPICAL SECTION ABOVE.
KOSRAE:
SCATTERED SHOWERS (OCCASIONALLY NUMEROUS) WILL REMAIN IN YOUR
FORECAST FUTURE THROUGH EARLY NEXT WEEK, AS A NEAR-EQUATORIAL TROUGH
IS NEARBY. ADDITIONALLY, KOSRAE MAY BECOME LOCATED INTO A DEVELOPING
SOUTHWESTERLY WEAK WIND FLOW AS INVEST 95 DEVELOPS EAST AND NORTH OF
THE AREA EARLY NEXT WEEK, WHICH ALSO ARGUED FOR KEEPING AT LEAST
SCATTERED SHOWERS (IN THE FORECAST TO START NEXT WEEK. WINDS WILL BE
VARIABLE (LIGHT TO GENTLE) WITH SEAS OF 3 TO 5 FEET THROUGH THE
FORECAST PERIOD.
POHNPEI:
YOU ALSO REMAIN NEAR THE EASTERN EDGE OF A SURFACE TROUGH, AS IT'S
POSITIONED JUST TO YOUR SOUTH. EASTERLY FLOW (ALBEIT WEEK) TO THE
NORTH OF THIS AREA WILL CREATE ENOUGH SURFACE CONVERGENCE FOR
SCATTERED SHOWERS TO PERSIST THROUGH FRIDAY, BEFORE SHOWERS DROP
BACK TO ISOLATED COVERAGE. MAINLY VARIABLE LIGHT TO GENTLE WINDS WITH
SEAS OF 3 TO 5 FEET WILL CONTINUE HERE AS WELL.
WESTERN MICRONESIA
AN UNSETTLED PATTERN REMAINS OVER EASTERN YAP STATE. AN EDDY IN THE
NEAR-EQUATORIAL TROUGH (NET) IS PRODUCING NUMEROUS SHOWERS SOME OF
WHICH MAY BE HEAVY AT TIMES AND ISOLATED THUNDERSTORMS. THIS FEATURE
DOES HAVE UPPER-LEVEL SUPPORT AS AN INTERACTING BETWEEN A NEAR BY
HIGH AND AN NEAR BY LOW WILL PROVIDE THE VENTILATION NEEDED TO
SUSTAIN SHOWERS. DAILY RAIN RATES ARE EXPECTED TO BE ABOUT AN INCH A
DAY OVER THE NEXT SEVERAL DAYS. AS THIS SYSTEM MOVES WESTWARDS THE
SOUTHERN EXTENT IS ANTICIPATED INTERACT WITH THE TROUGH THAT IS OVER
PALAU.
FOR PALAU, A TROUGH HAS SETTLED OVER THE REGION. SCATTERED SHOWERS
ARE ANTICIPATED FOR THE REGION. THIS TROUGH IS ANTICIPATED INTERACT
WITH THE UNSETTLED PATTERN IN YAP STATE, AROUND THURSDAY NIGHT. DAILY
RAIN RATES ARE EXPECTED TO BE AROUND 0.75 TO 1 INCH A DAY. SHOWERS
ARE ANTICIPATED TO REMAIN IN THE FORECAST THROUGH THE BEGINNING OF
NEXT WEEK.
FOR CHUUK, THE NET IS JUST TO THE NORTH OF WENO AND BUILDING
SOUTHWARD. THIS TROUGH IS PRODUCING SCATTERED TO NUMEROUS SHOWERS
AND ISOLATED THUNDERSTORMS. RAIN RATES ARE EXPECTED TO BE AROUND 0.5
TO 0.75 INCHES A DAY. THIS FEATURE IS EXPECTED TO REMAIN OVER OR
NEAR BY CHUUK THROUGH THE NEXT BEGINNING OF NEXT WEEK.
COMBINED SEAS OF 3 TO 5 FEET ARE EXPECTED THROUGH THE BEGINNING OF
NEXT WEEK. WINDS ARE EXPECTED TO BE LIGHT TO GENTLE. OVERALL BENIGN
SEAS CONDITIONS ARE EXPECT.
GUM WATCHES/WARNINGS/ADVISORIES
GU...NONE.
MP...NONE.
MARIANAS WATERS...NONE.
MARIANAS: OGLE
EAST MICRONESIA: DOLL
WEST MICRONESIA: BOWSHER
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