114  
WTPA41 PHFO 131458  
TCDCP1  
 
TROPICAL STORM HECTOR DISCUSSION NUMBER 53  
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP102018  
500 AM HST MON AUG 13 2018  
 
THE CORE OF HECTOR HAS BEEN NEARLY DEVOID OF DEEP CONVECTION SINCE  
LATE SUNDAY AFTERNOON. THE MOST RECENT ESTIMATE OF VERTICAL WIND  
SHEAR FROM SHIPS IS ABOUT 16 KNOTS FROM THE SOUTHWEST. A FEW  
THUNDERSTORMS HAVE RECENTLY DEVELOPED IN THE NORTHWEST SEMICIRCLE  
FAR FROM THE EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). HOWEVER,  
THIS DOES NOT APPEAR TO BE ENOUGH TO REVIVE HECTOR IN THE NEAR  
FUTURE. THE LATEST SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE  
T3.0/45 KNOTS FROM PHFO, SAB, AND JTWC. THE UW-CIMSS ADT ESTIMATE  
IS T2.0/30 KNOTS. BASED ON ALL OF THIS GUIDANCE, WE ARE LOWERING  
THE INITIAL INTENSITY TO 45 KNOTS, WHICH MAY BE GENEROUS, FOR THIS  
ADVISORY.  
 
SINCE WE CAN EASILY MONITOR THE MOVEMENT OF THE EXPOSED LLCC IN  
SATELLITE IMAGERY, THE INITIAL MOTION IS SET AT 290/15 KNOTS. THE  
TRACK FORECAST HAS BEEN ADJUSTED ONLY SLIGHTLY FROM THE PREVIOUS  
ONE. AGAIN, THE LATEST MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED  
THROUGH 72 HOURS, WITH THE SPREAD IN THE FORECAST TRACKS INCREASING  
ON DAYS 4 AND 5. HECTOR IS EXPECTED TO CONTINUE ON A WEST-NORTHWEST  
TRACK ALONG THE EASTERN PERIPHERY OF A RETROGRADING UPPER-LEVEL LOW  
LOCATED WEST OF THE INTERNATIONAL DATE LINE NEAR LONGITUDE 171E. AS  
THIS LOW ALOFT CONTINUES TO MOVE WEST, AN UPPER LEVEL RIDGE IS  
FORECAST TO BUILD NORTH OF THE HECTOR. THIS WILL LIKELY STEER THE  
TROPICAL STORM TOWARD THE WEST-NORTHWEST DURING THE NEXT 48 HOURS. A  
GRADUAL TURN TOWARD THE NORTHWEST IS EXPECTED AROUND 72 HOURS,  
FOLLOWED BY A TURN TOWARD THE NORTH ON DAYS 4 AND 5, AS HECTOR  
ROUNDS THE WESTERN END OF THE RIDGE. THE LATEST FORECAST TRACK  
REMAINS VERY CLOSE TO THE CONSENSUS GUIDANCE. NOTE THAT SINCE THE  
SYSTEM IS SHEARED, THE FORECAST TRACK IS ALSO CLOSE TO THE TABS  
THROUGH 48 HOURS.  
 
THE LATEST INTENSITY FORECAST IS ADJUSTED DOWNWARD DUE TO THE  
CONTINUED RELATIVELY RAPID WEAKENING OF HECTOR. THE FORECAST  
GUIDANCE SHOWS THE SHEAR MAY RELAX WITHIN 12 TO 24 HOURS, BUT THE  
SYSTEM WILL LIKELY BE WEAKER BY THIS TIME. IN ADDITION, IT WILL BE  
MOVING OVER COOLER SEA SURFACE TEMPERATURES. THE INTENSITY GUIDANCE  
IS IN FAIRLY GOOD AGREEMENT THROUGH 36 HOURS, SO CONFIDENCE DURING  
THIS PORTION OF THE FORECAST IS FAIRLY GOOD. MOST OF THE INTENSITY  
GUIDANCE LEVELS OFF DURING THE 36 THROUGH 48 HOUR TIME FRAME, WHILE  
THE SHIPS GUIDANCE AND GFS INDICATE SOME UNREALISTIC STRENGTHENING.  
THE MAIN WEAKENING TREND IS DURING DAYS 3 THROUGH 5. IN ADDITION,  
HECTOR IS FORECAST TO TRANSITION TO AN EXTRATROPICAL SYSTEM IN ABOUT  
96 HOURS.  
 
NOTE THAT LARGE BREAKING WAVES WILL LIKELY PERSIST THIS MORNING  
ALONG PORTIONS OF THE NORTHWESTERN HAWAIIAN ISLANDS, ESPECIALLY  
IN THE VICINITY OF KURE ATOLL AND MIDWAY ATOLL, DUE TO SOUTH AND  
SOUTHEAST SWELLS GENERATED BY HECTOR.  
 
THIS WILL BE THE FINAL ADVISORY FROM THE CENTRAL PACIFIC HURRICANE  
CENTER ON THIS SYSTEM. THE NEXT BULLETIN WILL BE ISSUED BY RSMC  
TOKYO JAPAN. FOR U.S. INTERESTS, SEE DEPARTMENT OF DEFENSE WARNINGS  
ISSUED BY THE JOINT TYPHOON WARNING CENTER IN HONOLULU, HAWAII.  
 
FORECAST POSITIONS AND MAX WINDS  
 
INIT 13/1500Z 25.3N 179.8E 45 KT 50 MPH  
12H 14/0000Z 26.2N 177.4E 40 KT 45 MPH  
24H 14/1200Z 27.4N 174.2E 40 KT 45 MPH  
36H 15/0000Z 28.5N 171.1E 35 KT 40 MPH  
48H 15/1200Z 29.9N 168.1E 35 KT 40 MPH  
72H 16/1200Z 33.0N 164.0E 30 KT 35 MPH  
96H 17/1200Z 37.5N 163.5E 30 KT 35 MPH...POST-TROP/EXTRATROP  
120H 18/1200Z 43.5N 166.5E 25 KT 30 MPH...POST-TROP/EXTRATROP  
 

 
FORECASTER HOUSTON  
 
 
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