015  
FXPQ50 PGUM 200752  
AFDGUM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TIYAN GU  
552 PM CHST SUN SEP 20 2026  
   
MARIANAS SYNOPSIS  
 
MOSTLY CLOUDY SKIES WITH ISOLATED SHOWERS AND LIGHT TO GENTLE WINDS  
PREVAIL ACROSS THE MARIANAS. ALTIMETRY SHOWS SEAS OF 4 TO 6 FEET  
WEST OF THE WATERS.  
 
 
   
DISCUSSION  
 
LATEST SATELLITE AND RADAR DATA SHOW MOSTLY CLOUDY SKIES WITH  
ISOLATED SHOWERS ACROSS THE REGION. INCREASING CONVECTION IS SEEN  
EAST OF THE COASTAL WATERS AND WILL APPROACH THE ISLANDS DURING THE  
EVENING, USHERING IN INCREASED SHOWERS AND THUNDERSTORMS LATER THIS  
EVENING, NEAR MIDNIGHT. OVERALL, AN UNSETTLED PATTERN LOOKS TO  
CONTINUE ACROSS THE MARIANAS THROUGH THE NEXT SEVERAL DAYS, WITH  
THE ISLANDS SEEING MOSTLY POPS (PROBABILITY OF PRECIPITATION) IN THE  
30 TO 50 PERCENT RANGE THROUGH THE WEEK. TINIAN AND SAIPAN WILL SEE  
SOME BRIEF PERIODS OF 20 PERCENT POPS EARLY IN THE WEEK. MEANWHILE,  
GUAM AND ROTA WILL SEE PERIODS OF LOCALLY HEAVY SHOWERS TUESDAY  
INTO TUESDAY NIGHT AS A WEAK DISTURBANCE DRIFTS BY SOUTH OF GUAM.  
 
 
   
MARINE  
 
NOT MUCH CHANGE IN THE MARINE FORECAST. A MIX OF SWELLS FROM VARYING  
DIRECTIONS ALONG WITH SMALL WIND WAVES WILL MAKE FOR SOME CHOPPY  
SEAS, THOUGH SEAS WILL SLOWLY FALL THROUGH THE WEEK FROM 4 TO 6 FEET  
DOWN TO AROUND 3 TO 4 FEET LATER IN THE WEEK. WINDS WILL REMAIN  
MOSTLY LIGHT TO GENTLE THROUGH THE WEEK.  
 
 
   
EASTERN MICRONESIA  
 
A WEAK, LOW PRESSURE SYSTEM IS STILL LOCATED NORTH OF KWAJALEIN THIS  
EVENING WITH GENTLE TO MODERATE WESTERLIES ACROSS POHNPEI AND KOSRAE,  
BECOMING LIGHT TO GENTLE UPON REACHING MAJURO. SCATTERED SHOWERS AND  
ISOLATED THUNDERSTORMS WILL BE POSSIBLE AT ALL FORECAST POINTS  
TONIGHT. A DRYER TREND WILL BEGIN FOR KOSRAE TOMORROW AND BY TUESDAY  
NIGHT FOR POHNPEI WITH ONLY ISOLATED SHOWERS EXPECTED. GENTLE TO  
MODERATE WEST WINDS WILL CONTINUE INTO MONDAY AT POHNPEI AND KOSRAE  
WITH WINDS EASING TO LIGHT TO GENTLE BY TUESDAY AS THE MONSOON FLOW  
LIFTS NORTHWARD. SOUTHWEST TO WEST WINDS AT MAJURO MAY BRIEFLY  
INCREASE TO GENTLE TO MODERATE TOMORROW BEFORE DROPPING BACK DOWN AND  
BECOMING LIGHT AND VARIABLE TOWARDS THE END OF THE WEEK. COMBINED  
SEAS OF 4 TO 6 FEET WILL CONTINUE THROUGH EARLY THIS WEEK AT ALL  
FORECAST POINTS BEFORE POSSIBLY DECREASING.  
 
 
   
WESTERN MICRONESIA  
 
A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED FOR YAP STATE. HEAVY  
SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THE MIDDLE OF NEXT  
WEEK, AND GUSTY WINDS AT TIMES NEAR THESE HEAVY SHOWERS.  
 
FOR PALAU, SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL PERSIST  
FOR THE NEXT FEW DAYS. THE MONSOON PATTERN THAT IS CURRENTLY OVER  
YAP STATE IS EXPECTED TO MOVE IN TO PALAU AROUND WEDNESDAY. SHOWERS  
ARE EXPECTED TO BE SCATTERED THROUGH THURSDAY AS THE MONSOON PATTERN  
MOVES INTO THE PHILIPPINE SEA. SEAS ARE EXPECTED TO REMAIN 3 TO 5  
FEET WITH WINDS LIGHT TO MODERATE.  
 
FOR YAP, THERE WILL BE WIDESPREAD LOCALLY HEAVY SHOWERS AND ISOLATED  
THUNDERSTORMS. WINDS NEAR THESE HEAVIER SHOWERS MAY BE GUSTY AT  
TIMES. MODELS INDICATE A POTENTIAL CIRCULATION THAT MAY DEVELOP AS  
THE PATTERN MOVES WESTWARD. SHOWERS MAY BEGIN TO WANE AS EARLY AS  
WEDNESDAY. RAIN TOTALS ARE ANTICIPATED TO BE 1 TO 2 INCHES A DAY.  
SEAS ARE EXPECTED TO BE 5 TO 6 FEET THROUGH WEDNESDAY BEFORE  
TAPERING DOWN TO 3 TO 5 FEET FOR THE LATTER HALF OF THE WEEK.  
 
FOR CHUUK, A SURFACE TROUGH INTERACTING WITH SOME MID-LEVEL  
CONVERGENCE IS PRODUCING SPORADIC SCATTERED SHOWERS AROUND THE  
COASTAL WATERS. THESE SHOWERS ARE ANTICIPATED TO FILL IN AND BRING  
RAIN TO THE ISLAND THROUGH TUESDAY. ONCE THIS TROUGH MOVE WESTWARDS,  
FAIRLY BENIGN WEATHER CONDITIONS ARE EXPECTED TO RETURN FOR THE  
REMAINDER OF THE WEEK. SEAS ARE EXPECTED TO BE 4 TO 6 FEET THROUGH  
ABOUT WEDNESDAY, THEN DROP BY A FOOT FOR THE LATER HALF OF THE WEEK.  
 
 
   
GUM WATCHES/WARNINGS/ADVISORIES  
 
GU...NONE.  
MP...NONE.  
MARIANAS WATERS...NONE.  
 
 
 
 
MARIANAS: KLEESCHULTE  
EAST MICRONESIA: OGLE  
WEST MICRONESIA: BOWSHER  
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