WTXS31 PGTW 092100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (BONGOYO) WARNING NR 006// RMKS/ 1. TROPICAL CYCLONE 02S (BONGOYO) WARNING NR 006 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 091800Z --- NEAR 20.7S 75.9E MOVEMENT PAST SIX HOURS - 225 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT REPEAT POSIT: 20.7S 75.9E --- FORECASTS: 12 HRS, VALID AT: 100600Z --- 20.9S 75.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 260 DEG/ 07 KTS --- 24 HRS, VALID AT: 101800Z --- 21.1S 74.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 270 DEG/ 12 KTS --- 36 HRS, VALID AT: 110600Z --- 21.0S 71.5E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 48 HR POSIT: 270 DEG/ 14 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 111800Z --- 20.9S 68.5E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 092100Z POSITION NEAR 20.7S 75.8E. 09DEC20. TROPICAL CYCLONE 02S (BONGOYO), LOCATED APPROXIMATELY 840 NM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE IMPACT OF VERTICAL WIND SHEAR, WITH MODERATE CONVECTION SHEARED TOWARDS THE SOUTHEAST OF THE ASSESSED LOW-LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 091658Z PARTIAL ASCAT-C PASS, WHICH CAPTURED THE CENTER AND THE EASTERN HALF OF THE SYSTEM. THE INITIAL INTENSITY IS ASSESSED AT 40 KNOTS WITH MODERATE CONFIDENCE, AS AN OVERALL AVERAGE OF DVORAK AND SCATTEROMETER ESTIMATES INCLUDING A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T2.5 (35 KTS), AN AUTOMATED DVORAK TECHNIQUE (ADT) ESTIMATE OF ADT 3.8 AND A SATELLITE CONSENSUS ESTIMATE OF 57 KNOTS. THE PREVIOUSLY MENTIONED ASCAT-C PASS INDICATED MAXIMUM WINDS NEAR 35 KNOTS IN THE SOUTHWESTERN AND EASTERN QUADRANTS. TC BONGOYO IS CURRENTLY TRACKING VERY SLOWLY SOUTHWESTWARD, AS THE PRIMARY STEERING MECHANISM IS CURRENTLY UNDERGOING A SHIFT. THE STRONG STR LOCATED TO THE SOUTHEAST REMAINS IN PLACE, HOWEVER THE SYSTEM IS BEING DECAPITATED BY SHEAR, AND THE LOW-LEVEL CIRCULATION IS NOW COMING UNDER THE STEERING INFLUENCE OF THE STRONG SURFACE HIGH PRESSURE SYSTEM TO THE SOUTHWEST. ENVIRONMENTAL ANALYSIS SHOWS THAT THE SYSTEM IS TRACKIN THROUGH AN UNFAVORABLE ENVIRONMENT CHARACTERIZED BY MODERATE (20-25 KTS) VERTICAL WIND SHEAR (VWS), COOL (25-26 CELSIUS) SEA SURFACE TEMPERATURES (SST) THAT IS OFFSET SLIGHTLY BY CONTINUED ROBUST POLEWARD OUTFLOW. THROUGH TAU 12 THE SYSTEM WILL TRACK GENERALLY SOUTHWESTWARD ALONG THE STEERING RIDGE, THEREAFTER AS THE LOW-LEVEL FLOW BECOMES THE DOMINATE STEERING PATTERN, THE SYSTEM SHIFTS TO A NEARLY DUE WEST TRACK THROUGH THE REMAINDER OF THE FORECAST. ENVIRONMENTAL CONDITIONS CONTINUE TO DETERIORATE THROUGH TAU 48, AND AFTER THE LOW-LEVEL CIRCULATION DECOUPLES COMPLETELY FROM THE UPPER-LEVEL CORE, THE SYSTEM WILL STEADILY WEAKEN, FULLY DISSIPATING BY TAU 48. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK WHICH IS LAID CLOSE TO THE MULTI-MODEL CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 091800Z IS 16 FEET. NEXT WARNINGS AT 100900Z AND 102100Z. REFER TO TROPICAL CYCLONE 03S (THREE) WARNINGS (WTXS32 PGTW) FOR SIX-HOURLY UPDATES.// NNNN