136 
 WTPA45 PHFO 200246
 TCDCP5
 
 TROPICAL DEPRESSION FIVE-C DISCUSSION NUMBER   5
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP052015
 500 PM HST SAT SEP 19 2015
  
 THE SATELLITE PRESENTATION OF THE DEPRESSION HAS DEGRADED SLIGHTLY 
 TODAY. LOW CLOUD VORTICES HAVE BEEN OBSERVED ROTATING AROUND A MEAN 
 ELONGATED CENTER WITH A SHARP LOW LEVEL TROUGH EXTENDING SEVERAL 
 HUNDRED MILES TO THE SOUTHWEST. DUE TO CONTINUED SOUTHWESTERLY 
 VERTICAL WIND SHEAR...DEEP CONVECTION HAS BECOME CONFINED TO THE 
 EAST AND SOUTH OF THE EXPOSED LOW LEVEL CENTER...AND A 2041 UTC 
 ASCAT PASS DETECTED NUMEROUS AREAS OF 30 KT WINDS WITHIN THIS BAND. 
 DVORAK CURRENT INTENSITY ESTIMATES WERE UNCHANGED FROM SIX HOURS 
 AGO...WITH HFO AND SAB COMING IN AT 2.0/30 KT AND JTWC AT 2.5/35
 KT. THE INITIAL INTENSITY WILL AGAIN BE HELD AT 30 KT.
 
 THE INITIAL MOTION IS TOWARD THE NORTH-NORTHEAST...OR 15 DEGREES... 
 AT 7 KT. THIS MOTION REPRESENTS THE OVERALL MOVEMENT OF THE MEAN 
 CENTER...WHICH HAS HAD INDIVIDUAL LOW CLOUD VORTICES BRIEFLY 
 ROTATING AROUND THE PERIPHERY THEN DISSIPATING. THE DEPRESSION IS 
 MOVING TOWARD THE NORTH-NORTHEAST BETWEEN A BROAD...DEEP AND SLOWLY 
 DIGGING TROUGH CENTERED TO THE NORTHWEST AND A LOW TO MID LEVEL 
 RIDGE LOCATED FAR TO THE NORTHEAST. THE CYCLONE IS EXPECTED TO 
 CONTINUE ON THE SAME GENERAL TRACK AND SLOWLY GAIN FORWARD SPEED 
 THROUGH SUNDAY AS INTERACTION WITH THE DEEP TROUGH INCREASES. A
 TURN TOWARD THE NORTH-NORTHWEST IS EXPECTED LATE MONDAY AND BEYOND
 AS THE SYSTEM BECOMES DRAWN INTO THE DEEP TROUGH. THE DYNAMICAL AND 
 CONSENSUS GUIDANCE ARE RATHER TIGHTLY CLUSTERED ALONG THE TRACK... 
 ESPECIALLY THROUGH 48 HOURS...BUT THERE IS CONSIDERABLE VARIABILITY 
 IN FORWARD SPEED OF THE INDIVIDUAL GUIDANCE MEMBERS. THE OFFICIAL 
 FORECAST IS NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE AND IS CLOSE
 TO THE GFEX AND TVCN.
 
 UNCERTAINTY IN THE INTENSITY FORECAST IS HIGH. THE LATEST CIMSS 
 ANALYSIS AND THE SHIPS INDICATE THAT SOUTHWESTERLY VERTICAL WIND 
 SHEAR REMAINS NEAR 25 KT. VERTICAL WIND SHEAR WILL HOLD AROUND THIS 
 LEVEL THROUGH ROUGHLY THE NEXT 24 HOURS THEN INCREASE SIGNIFICANTLY 
 AS THE CYCLONE MOVES CLOSER TO THE TROUGH TO THE NORTHWEST. AS A 
 RESULT...THE WINDOW FOR FIVE-C TO STRENGTHEN IS LIMITED...AND THE 
 LATEST SHIPS GUIDANCE STOPPED PREDICTING FURTHER INTENSIFICATION. 
 THE OFFICIAL FORECAST BRINGS THE CYCLONE TO TROPICAL STORM STRENGTH 
 BY 24 HOURS...THEN HOLDS THE SYSTEM STEADY STATE AS IT IS EXPECTED 
 TO BEGIN TRANSITION TO AN EXTRATROPICAL LOW ON MONDAY...POSSIBLY
 SOONER. THE INTENSITY FORECAST IS HIGHER THAN SHIPS BUT IS SLIGHTLY
 WEAKER THAN ICON IN THE 36 TO 48 HOUR TIME RANGE...MAINLY DUE TO THE
 INFLUENCE OF THE HWRF AND GFDL WHICH INTENSIFY THE SYSTEM
 AGGRESSIVELY.
 
 THERE ARE NO CHANGES TO THE WATCHES AND WARNINGS. A TROPICAL STORM 
 WARNING REMAINS IN EFFECT FOR CENTRAL PORTIONS OF THE 
 PAPAHANAUMOKUAKEA MARINE NATIONAL MONUMENT FROM FRENCH FRIGATE 
 SHOALS TO MARO REEF TO LISIANSKI ISLAND AND A TROPICAL STORM WATCH 
 REMAINS POSTED FROM LISIANSKI ISLAND TO PEARL AND HERMES.
  
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  20/0300Z 19.6N 174.2W   30 KT  35 MPH
  12H  20/1200Z 21.2N 173.7W   30 KT  35 MPH
  24H  21/0000Z 23.6N 173.0W   35 KT  40 MPH
  36H  21/1200Z 26.1N 172.2W   35 KT  40 MPH
  48H  22/0000Z 28.6N 172.0W   35 KT  40 MPH
  72H  23/0000Z 33.7N 173.2W   35 KT  40 MPH...POST-TROP/EXTRATROP
  96H  24/0000Z 39.6N 177.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
 120H  25/0000Z...DISSIPATED
  
 $$
 FORECASTER WROE