656  
FXPQ50 PGUM 271944  
AFDGUM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TIYAN GU  
544 AM CHST WED OCT 28 2026  
   
MARIANAS UPDATE
 
 
SCATTERED SHOWERS WILL LINGER THIS MORNING FOR TINIAN AND SAIPAN AS  
A TROUGH CONTINUES TO MOVES ACROSS THE REGION WITH SHOWER COVERAGE  
LIKELY DROPPING TO ISOLATED THIS AFTERNOON. ISOLATED SHOWERS ARE  
EXPECTED FOR GUAM AND ROTA THIS MORNING WITH SOME ISLAND-EFFECT  
SHOWERS AND A STRAY THUNDERSTORMS OR TWO POSSIBLE THIS AFTERNOON DUE  
TO LIGHTER WINDS, PARTICULARLY FOR GUAM. SHOWER COVERAGE WILL LIKELY  
REMAIN ISOLATED TONIGHT THROUGH THURSDAY FOR GUAM AND ROTA WITH  
ANOTHER ROUND OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS  
POSSIBLE AGAIN TONIGHT FOR TINIAN AND SAIPAN. GENTLE NORTHEAST WINDS  
WILL CONTINUE FOR SAIPAN AND TINIAN THROUGH TONIGHT AND POSSIBLY INTO  
THURSDAY WITH LIGHT WINDS PREVAILING FOR GUAM AND ROTA. COMBINED  
SEAS OF 5 TO 6 FEET WILL CONTINUE THROUGH THURSDAY, BEFORE A SHARPLY  
INCREASING FOR TINIAN AND SAIPAN STARTING LATE THURSDAY AHEAD OF  
TYPHOON IN-FA PASSING THROUGH THE FAR NORTHERN MARIANAS. A MARINE  
WEATHER STATEMENT REMAINS IN EFFECT FOR THE EXPECTED RAPIDLY BUILDING  
SEAS. OTHERWISE, A MODERATE RISK OF RIP CURRENTS WILL CONTINUE  
THROUGH THE WEEK ALONG NORTH AND EAST-FACING REEFS.  
 

 
   
TROPICAL SYSTEMS UPDATE
 
 
TYPHOON IN-FA IS MOVING WESTWARD THIS MORNING AROUND 6 MILES PER  
HOUR AND IS LOCATED NEAR 14.7N 160.8E. IN-FA IS EXPECTED TO MAINTAIN  
THIS GENERAL COURSE WITH AN INCREASE IN FORWARD SPEED THROUGH  
THURSDAY, WITH A PASSAGE THROUGH THE FAR NORTHERN MARIANAS EXPECTED  
ON FRIDAY. THE MAXIMUM SUSTAINED WINDS REMAIN AT 120 MPH. IN-FA IS  
FORECAST TO INTENSIFY THROUGH THURSDAY. TYPHOON FORCE WINDS EXTEND  
OUTWARD FROM THE CENTER UP TO 35 MILES. TROPICAL STORM FORCE WINDS  
EXTEND OUTWARD FROM THE CENTER UP TO 90 MILES.  
 
FOR MORE INFORMATION ON TYPHOON IN-FA, PLEASE REFER TO BULLETINS  
FROM THE JOINT TYPHOON WARNING CENTER UNDER WMO HEADER WTPN31 PGTW  
AND FROM THE NATIONAL WEATHER SERVICE UNDER WMO HEADER WTPQ31 PGUM.  
 

 
   
EASTERN MICRONESIA UPDATE
 
 
MOSTLY ISOLATED SHOWERS ARE EXPECTED TO PREVAIL THROUGH AT LEAST  
TODAY AT ALL FORECAST POINTS WITH SHOWER COVERAGE RAMPING UP TO  
SCATTERED ON THURSDAY AT MAJURO AS THE MONSOON TROUGH DRIFTS IN THE  
VICINITY OF THE ATOLL. GENTLE TO MODERATE WEST-SOUTHWEST WINDS WILL  
WEAKEN TODAY AT POHNPEI, AND BECOMING LIGHT TO GENTLE TONIGHT. WINDS  
WILL THEN BE LIGHT TO GENTLE AT ALL FORECAST POINTS FOR THE NEXT  
SEVERAL DAYS. COMBINED SEAS OF 4 TO 6 FEET WILL CONTINUE AT ALL  
FORECAST POINTS TODAY AND INTO THURSDAY, BEFORE DROPPING TO 4 TO 5  
FEET BY FRIDAY.  
 

 
   
WESTERN MICRONESIA UPDATE
 
 
GENERALLY DRIER WEATHER IS EXPECTED OVER THE NEXT DAY OR SO ACROSS  
MUCH OF WESTERN MICRONESIA. SHOWER CHANCES WILL TOP OUT AROUND 30  
PERCENT AT PALAU AND CHUUK TODAY. LIGHT TO GENTLE WINDS WILL PREVAIL  
AT PALAU AND YAP WITH GENTLE TO MODERATE SOUTHWEST WINDS EXPECTED  
STARTING TONIGHT AT CHUUK. COMBINED SEAS OF 3 TO 5 WILL CONTINUE AT  
ALL SITES THROUGH THURSDAY.  
 

 
   
PREV DISCUSSION
 
/ISSUED 624 PM CHST TUE OCT 27 2026/  
 
MARIANAS SYNOPSIS...  
LIGHT TO GENTLE NORTH WINDS ARE VISIBLE OVER GUAM AND ROTA THIS  
EVENING WITH GENTLE TO MODERATE EAST-NORTHEASTERLIES OVER TINIAN AND  
SAIPAN. ISOLATED SHOWERS REMAIN OVER GUAM AND ROTA WITH HIGH-END  
SCATTERED SHOWERS OVER TINIAN AND SAIPAN AS A TROUGH MOVES THROUGH  
SLOWLY. MODEL AND OBSERVATION DATA INDICATE COMBINED SEAS OF 5 TO 6  
FEET.  
 
DISCUSSION...  
ISOLATED SHOWERS TONIGHT ACROSS GUAM AND ROTA ARE EXPECTED TO  
CONTINUE FOR THE WHOLE FORECAST PERIOD WITH THE EXCEPTION OF  
SCATTERED ISLAND EFFECT SHOWERS IN THE AFTERNOON WEDNESDAY. FOR THE  
TINIAN AND SAIPAN, A TROUGH WILL CONTINUE TO MOVE THROUGH THE REGION  
AND BRING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TONIGHT,  
BECOMING ISOLATED WEDNESDAY. SHOWERS WILL LIKELY REMAIN ISOLATED  
UNTIL FRIDAY WHEN SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS RETURN  
UPON THE PASSAGE OF TYPHOON IN-FA SOMEWHERE TO THE NORTH THROUGH THE  
FAR NORTHERN CNMI ANYWHERE FROM JUST NORTH OF SAIPAN TO MAUG ISLAND.  
SHOWERS FOR TINIAN AND SAIPAN WILL LIKELY RETURN TO ISOLATED FOR THE  
REST OF THE FORECAST PERIOD BY SATURDAY. CURRENT TYPHOON IN-FA IS  
EXPECTED TO MAKE IT'S CLOSEST POINT OF APPROACH SOMETIME FRIDAY.  
BREEZY CONDITIONS CAN BE EXPECTED FOR TINIAN AND SAIPAN FRIDAY WITH  
SUSTAINED WINDS UP TO 30 MPH AND GUSTS TO 45 MPH. THE CURRENT JTWC  
TRACK PUTS ONLY A 10-20% CHANCE OF TROPICAL STORM SUSTAINED WINDS FOR  
TINIAN AND SAIPAN. THIS SITUATION REMAINS HIGHLY UNCERTAIN AND WILL  
CONTINUE TO BE MONITORED CLOSELY FOR ANY POTENTIAL CHANGES. SEE THE  
"TROPICAL SYSTEMS" SECTION FOR MORE DETAILS.  
 
MARINE...  
GENTLE NORTHEAST WINDS WILL PREVAIL ACROSS TINIAN AND SAIPAN  
THROUGH AT LEAST WEDNESDAY NIGHT, WHILE MOSTLY LIGHT WINDS PREVAIL  
OVER ROTA AND GUAM. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS  
WILL BE POSSIBLE FOR TINIAN AND SAIPAN TONIGHT AS A TROUGH MOVES  
THROUGH THE REGION, WITH ISOLATED THUNDERSTORMS POSSIBLE FOR ALL  
ISLANDS WEDNESDAY. THEREFORE, THERE IS A MODERATE RISK OF LIGHTNING  
ALONG THE COASTLINES TONIGHT FOR TINIAN AND SAIPAN, AND ALL ISLANDS  
WEDNESDAY. THERE WILL BE A MODERATE RISK OF RIP CURRENTS ALL WEEK FOR NORTH-  
AND EAST-FACING REEFS DUE TO A PRIMARY EAST-NORTHEAST SWELL AND A  
SECONDARY WEST-NORTHWEST SWELL THAT WILL BECOME NEGLIGIBLE BY  
WEDNESDAY. COMBINED SEAS ARE EXPECTED TO WAVER BETWEEN 5 AND 6 FEET  
THROUGH THURSDAY. BY LATE THURSDAY, SEAS ARE EXPECTED TO INCREASE  
SIGNIFICANTLY AND BECOME HAZARDOUS AHEAD OF TYPHOON IN-FA THAT IS  
ANTICIPATED TO PASS SOMEWHERE THROUGH THE FAR NORTHERN CNMI BETWEEN  
JUST NORTH OF SAIPAN TO MAUG ISLAND. WIDESPREAD SEAS OF 10 TO 15 FEET  
ARE EXPECTED FOR TINIAN AND SAIPAN WITH SEAS POTENTIALLY UP TO 20  
FEET POSSIBLE IF IN-FA TAKES A MORE SOUTHERN TRACK. SEAS OF 10+ FEET  
ARE ALSO POSSIBLE FOR GUAM AND ROTA. THEREFORE, THE SURF WILL ALSO BE  
HAZARDOUS ON ALL ISLANDS, PARTICULARITY FOR NORTH AND EAST FACING  
REEFS.  
 
TROPICAL SYSTEMS...  
AT 1 PM CHST, TYPHOON IN-FA WAS LOCATED 205 MILES NORTH OF ENEWETAK,  
ABOUT 1265 MILES EAST OF GUAM, NEAR 14N162E. IN-FA IS NEARLY  
STATIONARY, MOVING WEST AT ONLY 1 MPH. MAXIMUM SUSTAINED WINDS WERE  
125 MPH. TY IN-FA IS EXPECTED TO MOVE WEST THROUGH THURSDAY, THEN  
BEGIN TO TURN WEST-NORTHWEST BY FRIDAY, HEADING TOWARD THE ISLAND OF  
PAGAN IN THE FAR NORTHERN CNMI. IN-FA IS EXPECTED TO WEAKEN SLIGHTLY  
THROUGH TONIGHT, THEN BEGIN TO STRENGTHEN AGAIN WEDNESDAY. TY IN-FA  
COULD BECOME A SUPER TYPHOON AS EARLY AS THURSDAY, AND REACH THE  
NORTHERN CNMI AT THAT INTENSITY FRIDAY AFTERNOON. RESIDENTS OF  
TINIAN, SAIPAN AND THE FAR NORTHERN CNMI SHOULD CONTINUE TO MONITOR  
FORECASTS FOR ANY UPDATES OR CHANGES AND THE POSSIBILITY OF ANY  
WATCHES OR WARNINGS, AS CHANGES IN INTENSITY, TRACK AND TIMING WILL  
OCCUR OVER THE NEXT FEW DAYS. A SIGNIFICANT SHIFT SOUTH COULD BRING  
TC CONDITIONS TO TINIAN AND SAIPAN, THOUGH THIS IS NOT EXPECTED AT  
THIS TIME.  
 
FOR MORE INFORMATION ON TY IN-FA, SEE BULLETINS ISSUED BY THE JOINT  
TYPHOON WARNING CENTER UNDER WMO HEADER WTPN31 PGTW AND BY THE  
NATIONAL WEATHER SERVICE UNDER WMO HEADER WTPQ31 PGUM.  
 
EASTERN MICRONESIA...  
A FAIRLY DRY PATTERN IS IN STORE FOR EASTERN MICRONESIA THROUGH THE  
WEEKEND. MOSTLY CLEAR SKIES ARE EXPECTED AT MAJURO AND KOSRAE  
TONIGHT, CONTINUING AT KOSRAE THROUGH WEDNESDAY NIGHT. THE MOST THAT  
CAN BE EXPECTED FOR POHNPEI AND KOSRAE IS ONLY ISOLATED SHOWERS  
THROUGH THE WEEKEND. FOR MAJURO, THE MONSOON TROUGH LOOKS TO DRIFT  
WEST OVER THE NEXT COUPLE DAYS, WITH A BAND OF WEAK CONVERGENCE  
SETTING UP BRIEFLY OVER MAJURO. THIS IS EXPECTED TO BRING SCATTERED  
SHOWERS TO THE ATOLL WEDNESDAY THROUGH WEDNESDAY NIGHT. BY THURSDAY,  
THE DRY PATTERN LOOKS TO RETURN TO MAJURO.  
 
FOR THE MARINE FORECAST, NOTHING HAS REALLY CHANGED. STILL LOOKS LIKE  
COMBINED SEAS AT OR BELOW 6 FEET THROUGH THE WEEKEND. GENTLE TO  
MODERATE WINDS AT POHNPEI WILL SUBSIDE TO LIGHT TO GENTLE BY  
THURSDAY, WHILE LIGHT TO GENTLE WINDS WILL PREVAIL AT KOSRAE AND  
MAJURO THROUGH THE WEEKEND.  
 
WESTERN MICRONESIA...  
THE MAIN FORECAST CHALLENGE CONTINUES TO BE ANY RAINFALL FOR PALAU  
AND YAP IN THE SHORT TERM, AS THE MONSOON TROUGH REMAINS OVERHEAD OR  
VERY NEAR HERE. HOWEVER, THE LATEST INFRARED SATELLITE IMAGERY SHOWS  
RAPIDLY WARMING CLOUD TOPS. A WEAK CIRCULATION THAT WAS NEAR THERE  
THE LAST 48 HRS HAS DISSOLVED. AS SUCH, OPTED FOR JUST ISOLATED  
SHOWERS THROUGH THURSDAY NIGHT. THEREAFTER, THE SOUTHWEST MONSOON  
FLOW WILL BRIEFLY STRENGTHEN AT CHUUK THURSDAY, ASSOCIATED WITH  
TYPHOON IN-FA. THEN, IT QUICKLY (THE MONSOON TROUGH AND AREA OF  
INCREASED WINDS/SURFACE CONVERGENCE) PEELS WEST THURSDAY NIGHT,  
ARRIVING AND PALAU AND YAP FRIDAY INTO SATURDAY. THIS WILL NEED TO BE  
WATCHED THOUGH (IN-FA AND THE MONSOON TROUGH) AS THERE'S SOME  
CONCERNS THAT IN-FA COULD TAKE A MORE SOUTHERLY TRACK THEN CURRENTLY  
FORECAST, WHICH COULD IN TURN PROLONG INFLOW-RELATED CONVECTION.  
 
OTHERWISE, SEAS OF 3 TO 5 FEET WILL BRIEFLY INCREASE A FOOT FRIDAY,  
INTO SATURDAY, MAINLY NEAR YAP, AS IN-FA PASSES THROUGH THE NORTHERN  
CNMI, THE WINDS WILL GENERALLY BE LIGHT TO GENTLE, ALBEIT BRIEFLY  
HIGHER AT CHUUK THURSDAY AS THE SOUTHWESTERLY INFLOW INTO IN-FA  
BRIEFLY STRENGTHENS.  
 

 
   
GUM WATCHES/WARNINGS/ADVISORIES
 
 
GU...NONE.  
MP...NONE.  
MARIANAS WATERS...NONE.  

 
 

 
 
MARIANAS/EAST AND WEST MICRONESIA/TROPICAL UPDATE: WHISNANT  
MARIANAS: OGLE  
EAST MICRONESIA/TROPICAL: KLEESCHULTE  
WEST MICRONESIA: DOLL  
 
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