ABPW10 PGTW 080600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS/080600Z-090600ZOCT2021//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/080151ZOCT2021//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 08OCT21 0000Z, TROPICAL STORM 22W (LIONROCK) WAS 
LOCATED NEAR 17.8N 110.8E, APPROXIMATELY 180 NM NORTHEAST OF DA 
NANG, VIETNAM, AND HAD TRACKED NORTH-NORTHWESTWARD AT 06 KNOTS OVER 
THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED 
AT 35 KNOTS GUSTING TO 45 KNOTS. SEE REF A (WTPN31 PGTW 080300) FOR 
FURTHER DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED 
NEAR 13.1N 131.4E IS NOW LOCATED NEAR 12.4N 131.3E, APPROXIMATELY  
617NM EAST OF MANILA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
DEPICTS AN EXPOSED, BROAD LOW-LEVEL CIRCULATION (LLC) WITH EXTENSIVE 
CONVECTION OVER THE SOUTHERN SEMICIRCLE ASSOCIATED WITH CONVERGENT 
LOW-LEVEL WESTERLIES. A 080036Z ASCAT-B IMAGE REVEALS A DEFINED, 
ELONGATED CIRCULATION WITH 25-30 KNOT WESTERLIES AND WEAKER WINDS 
(05-20 KNOTS) ELSEWHERE. A 080444Z AMSR2 89GHZ COMPOSITE IMAGE SHOWS 
FRAGMENTED BANDING OVER THE WESTERN AND SOUTHERN PERIPHERIES BUT 
LITTLE EVIDENCE OF A DEFINED LLC. UPPER-LEVEL ANALYSIS INDICATES A 
MARGINAL ENVIRONMENT WITH CONVERGENT NORTHERLY FLOW OVER THE LLC AND 
LOW TO MODERATE (10-20 KTS) VERTICAL WIND SHEAR. GLOBAL MODELS 
INDICATE INVEST 93W WILL MERGE WITH INVEST 94W IN THE NEXT FEW DAYS. 
THERE IS SIGNIFICANT UNCERTAINTY IN HOW THESE TWO SYSTEMS WILL 
DEVELOP AND MERGE WITH HIGH UNCERTAINTY IN TRACK MOTION AS WELL. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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 IS UPGRADED TO MEDIUM.
      (2) THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED 
NEAR 15.5N 137.7E IS NOW LOCATED NEAR 15.6N 137.1E, APPROXIMATELY  
460NM WEST-NORTHWEST OF GUAM. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY DEPICTS A BROAD, EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH 
STRONG LOW-LEVEL CONVERGENCE FUELING EXTENSIVE DEEP CONVECTION OVER 
THE EASTERN SEMICIRCLE. RECENT MICROWAVE IMAGERY REVEALS STRONG 
CONVECTIVE BANDS OVER THE EASTERN AND SOUTHERN PERIPHERIES BUT 
LITTLE EVIDENCE OF A DISTINCT LLC. A 072318Z ASCAT-A IMAGE REVEALS 
SHARP TURNING WITH A SWATH OF 25-30 KNOT WINDS OVER THE EASTERN 
SEMICIRCLE BUT NO CLOSED CIRCULATION YET. GLOBAL MODELS INDICATE 
THAT INVEST 93W WILL MERGE WITH INVEST 94W OVER THE NEXT FEW DAYS. 
THERE IS SIGNIFICANT UNCERTAINTY IN HOW THESE TWO SYSTEMS WILL 
DEVELOP AND MERGE WITH HIGH UNCERTAINTY IN TRACK MOTION AS WELL.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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 IS UPGRADED TO MEDIUM.
      (3) THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED 
NEAR 14.5N 166.5E IS NOW LOCATED NEAR 14.8N 166.0E, APPROXIMATELY 
272NM SOUTH OF WAKE ISLAND. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY DEPICTS A DISORGANIZED DISTURBANCE WITH WANING CONVECTION. A 
072253 ASCAT-B IMAGE SHOWS A TIGHTENING LOW LEVEL CIRCULATION WITH 
HIGHER WINDS (20 KNOTS) OFFSET OVER THE EASTERN SEMICIRCLE. 
ENVIRONMENTAL ANALYSIS INDICATES FAVORABLE CONDITIONS FOR 
DEVELOPMENT, WITH ROBUST POLEWARD OUTFLOW, ENHANCED BY UPPER LOWS TO 
THE NORTHWEST AND NORTHEAST, LOW (5-10 KTS) VERTICAL WIND SHEAR 
(VWS), AND WARM (30C) SEA SURFACE TEMPERATURES (SST). NUMERICAL 
MODELS ARE IN GENERAL AGREEMENT THAT INVEST 95W WILL TRACK WEST-
NORTHWESTWARD AND INTENSIFY OVER THE NEXT 24 TO 48 HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL FOR 
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 
HOURS REMAINS MEDIUM.
      (4) 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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