563  
FXPQ60 PGUM 232124  
AFDPQ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE TIYAN GU  
638 AM CHST FRI NOV 24 2017  
   
MARIANAS SYNOPSIS
 
EAST TRADE-WINDS AND ISOLATED SHOWERS PREVAIL  
ACROSS THE MARIANAS THIS MORNING.  
 

 
   
DISCUSSION
 
 
LITTLE CHANGE MADE TO THE FORECAST. DID UPDATE WINDS WITH NEW MODEL  
DATA. AN AREA OF HIGH PRESSURE IS NOW MOVING OFF OF ASIA AND WILL  
MOVE ACROSS THE WESTERN NORTH PACIFIC THE NEXT SEVERAL DAYS. THE  
PRESSURE GRADIENT BETWEEN THIS HIGH PRESSURE AND LOWER PRESSURE SOUTH  
OF 10N WILL PRODUCE BREEZY EAST TO NORTHEAST WINDS OF BETWEEN 10 TO  
25 MPH THROUGH THE WEEKEND.  
 
DEEP-LAYER MOISTURE WILL BE LOW THIS WEEKEND AND SKIES WILL BE PARTLY  
CLOUDY. TRADE-WIND CONVERGENCE WILL INCREASE THE MOISTURE WITH MOSTLY  
CLOUDY SKIES PREVAILING FOR AT LEAST THE FIRST HALF OF THE COMING  
WEEK.  
 

 
   
MARINE
 
 
IPAN...TANAPAG AND RITIDIAN BUOYS SHOW SEA HEIGHTS BETWEEN 6 AND 7  
FEET. SATELLITE ALTIMETRY DATA ALSO SHOWS 6 TO 7 FOOT SEAS OVER THE  
LOCAL AREA. TANAPAG AND RITIDIAN SHOW JUST A NORTHEAST SWELL. MODEL  
DATA KEEPS A NORTHERLY SWELL OVER THE AREA AND THERE IS A FAINT HINT  
OF IT IN THE RITIDIAN BUOY DATA. THE NORTHEAST SWELL WILL PERSIST  
THROUGH THE FORECAST. MODEL DATA KEEP THE NORTH SWELL THROUGH  
SATURDAY NIGHT. IT WILL BRIEFLY BE REPLACED BY A NORTHWEST SWELL THAT  
WILL OCCUR SUNDAY THROUGH MONDAY.  
 
AS MENTIONED ABOVE...WINDS WILL INCREASE OVER THE WEEKEND AND MOST  
LIKELY WILL REACH SMALL CRAFT CRITERIA. SEA HEIGHTS WILL ALSO  
INCREASE ENOUGH THAT SMALL CRAFT ADVISORY CONDITIONS OF 10 FEET ARE  
POSSIBLE FOR PART OF THE WEEKEND. THIS INCREASE IN SEA HEIGHTS AND  
WIND WAVES COMBINED WITH A SLIGHT INCREASE IN SWELL HEIGHTS MAY ALSO  
GENERATE HAZARDOUS SURF CONDITIONS ON NORTH AND EAST FACING REEFS BY  
SUNDAY AND CONTINUING THROUGH EARLY NEXT WEEK.  
 

 
   
EASTERN MICRONESIA
 
 
A FEW SHOWERS AND THUNDERSTORMS PERSIST JUST SOUTH OF POHNPEI AND  
EAST OF MAJURO, BUT DRY WEATHER IS OTHERWISE SEEN ACROSS THE AREA.  
WHILE FAIRLY DRY WEATHER IS EXPECTED TO CONTINUE FOR THE REGION,  
ISOLATED THUNDERSTORMS WILL MOVE INTO MAJURO WATERS LATER TODAY.  
SHOWERS WILL INCREASE OVER THE WEEKEND. INCREASING TRADE-WIND  
CONVERGENCE WILL MAINTAIN WET CONDITIONS THERE INTO EARLY NEXT WEEK,  
WHILE ALSO BRINGING WETTER WEATHER TO KOSRAE AND POHNPEI AROUND  
TUESDAY.  
 
WINDS AND SEAS WILL RISE IN THE MARSHALLS LATE IN THE WEEKEND AND  
EARLY NEXT WEEK, AND COULD APPROACH LEVELS HAZARDOUS TO SMALL CRAFT  
OPERATIONS AND PRODUCE HAZARDOUS SURF CONDITIONS. SEAS, WINDS AND  
SURF WILL ALSO BUILD SOME AT POHNPEI AND KOSRAE.  
 

 
   
WESTERN MICRONESIA
 
 
OVERNIGHT SURFACE ANALYSIS INDICATED A WEAK CIRCULATION SOUTH OF  
KOROR NEAR 4N134E WITH A TROUGH EXTENDING TO THE WEST AND THE  
NORTHEAST. LITTLE CONVECTION IS SEEN NEAR THESE FEATURES, BUT A THICK  
BAND OF SHOWERS AND THUNDERSTORMS HAS PERSISTED WITHIN CONVERGENT  
TRADE-WIND FLOW TO THE NORTH. SCATTERED SHOWERS AND ISOLATED  
THUNDERSTORMS EAST OF KOROR WILL MOVE INTO THE AREA LATER THIS  
MORNING AND CONTINUE THROUGH SATURDAY NIGHT. YAP IS JUST ON THE  
NORTHERN EDGE OF CONVECTION SO HAVE GONE WITH A SPLIT FORECAST FOR  
TODAY WITH HEAVIER SHOWERS AND THUNDERSTORMS OVER THE SOUTHERN WATERS  
WITH SLIGHTLY DRIER CONDITIONS NORTH OF YAP. INCREASING NORTHEAST  
TRADES ARE EXPECTED TO PUSH CONVECTION SOUTHWEST THIS EVENING. DRIER  
WEATHER IS EXPECTED FOR BOTH YAP AND KOROR LATER IN THE WEEKEND.  
 
AT CHUUK, SHOWERS AND THUNDERSTORMS WILL SLOWLY SHIFT TO THE WEST AND  
SOUTHWEST THIS AFTERNOON AND EVENING. A DRIER TRADE-WIND PATTERN WILL  
DOMINATE THROUGH THE WEEKEND WITH A FEW MORE CLOUDS AND SHOWERS  
EXPECTED BY TUESDAY.  
 
FRESH TO STRONG TRADE WINDS AT YAP WILL BE HAZARDOUS TO SMALL CRAFT  
OPERATIONS THE NEXT FEW DAYS. IN ADDITION, WINDS AT KOROR WILL  
INCREASE TO NEAR ADVISORY LEVELS THE NEXT FEW DAYS. SEAS ARE  
CURRENTLY FORECAST TO STAY BELOW SMALL CRAFT CRITERIA AT ALL THREE  
FORECAST POINTS FOR NOW, HOWEVER, SEAS WILL BE MONITORED FOR POSSIBLE  
SMALL CRAFT CRITERIA OVER THE NEXT COUPLE OF DAYS. SURF ALONG NORTH  
AND EAST SHORES WILL ALSO RISE AND COULD REACH HAZARDOUS SURF HEIGHTS  
OVER THE WEEKEND.  
 

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

 
 

 
 
ZIOBRO/W. AYDLETT  
 
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