ABPW10 PGTW 170600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH 
PACIFIC OCEANS/170600Z-180600ZSEP2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/170151ZSEP2025//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 17SEP25 0000Z, TROPICAL DEPRESSION 23W (TWENTYTHREE) WAS 
LOCATED NEAR 16.9N 121.8E, APPROXIMATELY 146 NM NORTH-NORTHEAST OF 
MANILA, PHILIPPINES, AND HAD TRACKED NORTH-NORTHWESTWARD AT 09 KNOTS 
OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE 
ESTIMATED AT 30 KNOTS GUSTING TO 40 KNOTS. SEE REF A (WTPN31 PGTW 
170300) FOR FURTHER DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR 
13.4N 137.1E IS NOW LOCATED NEAR 13.6N 136.6E, APPROXIMATELY 262 NM 
NORTH-NORTHWEST OF YAP. ANIMATED MULTISPECTRAL IMAGERY (MSI) DEPICTS 
A POORLY ORGANIZED BROAD CIRCULATION CENTER WITH DISSIPATING CENTRAL 
CONVECTION. ENVIRONMENTAL ANALYSIS REVEALS MARGINAL TO FAVORABLE 
CONDITIONS FOR DEVELOPMENT WITH LOW TO MODERATE VERTICAL WIND SHEAR 
(15-20 KNOTS), POLEWARD UPPER-LEVEL OUTFLOW ALOFT, AND WARM SEA 
SURFACE (28-29 C) TEMPERATURES. GLOBAL MODELS ARE IN AGREEMENT THAT 
INVEST 9OW WILL STEADILY DEVELOP ALONG A GENERALLY WEST-NORTHWESTWARD 
TRACK OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE 
ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED 
TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
      (2) THE AREA OF CONVECTION (INVEST 91W) PREVIOUSLY LOCATED NEAR 
22.8N 167.7E IS NOW LOCATED NEAR 22.9N 167.1E, APPROXIMATELY 219 NM 
NORTH OF WAKE. ANIMATED MULTISPECTRAL IMAGERY (MSI) DEPICTS AN ILL-
DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION 
WRAPPING ALONG THE WESTERN PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS 
A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW VERTICAL WIND SHEAR 
(15 KNOTS OR LESS), GOOD POLEWARD OUTFLOW ALOFT, AND WARM SEA SURFACE 
(30-31 C) TEMPERATURES.  DETERMINISTIC MODELS ARE IN AGREEMENT THAT 
INVEST 91W WILL HAVE A WEST-NORTHWESTWARD TRACK, BUT DISAGREE ON 
DEVELOPMENT TIMELINE. PRIMARILY, ECMWF DEVELOPS INVEST 91W THE 
STRONGEST COMPARED TO THE OTHER DETERMINISTIC MODELS. HOWEVER, BOTH 
ECENS AND GEFS ENSEMBLE SOLUTIONS SHOWS STRONGER INTENSIFICATION 
COMPARED TO THE DETERMINISTIC MODELS. MAXIMUM SUSTAINED SURFACE WINDS 
ARE ESTIMATED AT 13 TO 18 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 1013 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.
      (3) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
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