ABPW10 PGTW 160600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS 160600Z-170600ZJUL2021//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/152021ZJUL2021//
REF A IS A TROPICAL FORMATION ALERT.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED 
NEAR 17.4N 132.2E IS NOW LOCATED NEAR 17.7N 134.4E, APPROXIMATELY 
582 NM SOUTH-SOUTHEAST OF KADENA AB. ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY (MSI) DEPICTS PERSISTENT CONVECTION OBSCURING A 
LOW LEVEL CIRUCLATION CENTER (LLCC). THE CONVECTION HAS IMPROVED 
CONSIDERABLY OVER THE PAST 12 HOURS. ENVIRONMENTAL ANALYSIS 
INDICATES FAVORABLE CONDITIONS FOR DEVELOPMENT WITH GOOD POLEWARD 
OUTFLOW ALOFT, WARM (30-31C) SEA SURFACE TEMPERATURES, AND LOW (05-
10 KTS) VERTICAL WIND SHEAR (VWS). IN THE UPPER LEVELS, THE PATTERN 
IS COMPLEX WITH MULTIPLE STEERING FORCES. THE FAVORABLE POLEWARD 
POSITIONING OF AN UPPER LEVEL LOW IS ENHANCING OUTFLOW AND 
DIVERGENCE ALOFT, WHILE IN THE LOWER LEVELS A STRONG WESTERLY 
COMPONENT WILL ENHANCE CONSOLIDATION. THIS COMPLEX UPPER LEVEL 
PATTERN IS DRIVING DIVERGENCE IN NUMERICAL MODELS SOLUTIONS IN BOTH 
THE TRACK AND INTENSIFICATION GUIDANCE. GLOBAL AND ENSEMBLE GFS 
SOLTUIONS DEPICT 98W INTENSIFYING WITHIN 18-36 HOURS AND TRACKING 
WEST-NORTHWEST AT A HIGHER SPEED OF ADVANCE TO THE RYUKYU ISLANDS, 
WHILE GLOBAL AND ENSEMBLE ECMWF HAVE A GRADUAL INTENSIFICATION 
PATTERN WITH A SLOWER SPEED OF ADVANCE TO KYUSHU, JAPAN. CURRENT 
ANALYSIS INDICATES THAT ECMWF HAS BEEN THE MORE CONSISTENT MODEL AT 
HANDLING THE COMPLEXITIES OF 98W OVER THE LAST 48 HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR 
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 
HOURS REMAINS HIGH. SEE REF A (WTPN21 PGTW 152030) FOR FURTHER 
DETAILS.
      (2) 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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