WDXS31 PGTW 210300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 05S (FINA) WARNING NR 012// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 10.3S 132.5E INITIAL INTENSITY: 65 KTS GEOGRAPHIC REFERENCE: 162 NM NORTHEAST OF DARWIN, AUSTRALIA MOVEMENT PAST 6 HOURS: WESTWARD AT 05 KTS SIGNIFICANT WAVE HEIGHT: 21 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI), ANIMATED RADAR DATA AND REANALYSIS OF EARLIER MICROWAVE IMAGERY SUGGESTS THAT TC 05S HAS TRACED A RATHER ERRATIC TRACK OVER THE PAST 12 HOURS, AS THE VORTEX HAS SLOWLY BUT STEADILY ALIGNED. A 201844Z GMI PASS INDICATED A WELL-DEFINED MICROWAVE EYE FEATURE, AS DID A 202113Z SSMIS PASS, SUPPORTING A SHIFT IN THE TRACK FROM SOUTHWARD TO WESTWARD DURING THIS TIMEFRAME. RADAR IMAGERY UP TO 0000Z SHOWED A RAPIDLY CONSOLIDATING AND IMPROVING EYE STRUCTURE, WITH WELL-DEFINED SPIRAL BANDS OF DEEP CONVECTION WRAPPING UPSHEAR AND A NASCENT EYE BEGINNING TO FORM. HOWEVER, THE LAST COUPLE HOURS OF RADAR DATA SHOWS A MORE SLOPPY AND DEGRADED STRUCTURE, AND ALSO SUGGESTS THE LOW TO MID-LEVEL CIRCULATION CENTER (LLCC) MAY BE DRIFTING BACK TOWARDS THE EAST. ANIMATED WATER VAPOR IMAGERY AND CIMSS HIGH-RESOLUTION ATMOSPHERIC MOTION VECTORS (AMVS) SHOWS A STRONG OUTFLOW FRONT, ARC CLOUD PUSHING EAST AND NORTH FROM THE LLCC HOWEVER, THE MOST RECENT ENHANCED INFRARED IMAGERY SHOWS THE CENTRAL DENSE OVERCAST (CDO) BECOMING LESS ORGANIZED AND LESS SYMMETRICAL OVER THE PAST HOUR. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE RADAR DATA AND EXTRAPOLATION OF THE MICROWAVE IMAGERY NOTED ABOVE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE, HEDGED TOWARDS THE HIGHER PGTW FIX THAN THE BULK OF THE SUBJECTIVE AND OBJECTIVE ESTIMATES NOTED BELOW. ENVIRONMENTAL CONDITIONS HAVE IMPROVED, WITH DEEP-LAYER SHEAR NOW BELOW 15 KNOTS, IMPROVING OUTFLOW ALOFT AND VERY WARM SSTS. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: CURRENTLY THE SYSTEM IS IN THE MIDST OF A STEERING INFLUENCE SHIFT, FROM A WEAK AND COMPETING PATTERN TO THE SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST, CENTERED ALONG THE SOUTH COAST OF THE GULF OF CARPENTARIA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS ADRM: T3.5 - 55 KTS CIMSS SATCON: 46 KTS AT 202300Z CIMSS ADT: 59 KTS AT 210030Z CIMSS AIDT: 49 KTS AT 210030Z CIMSS D-MINT: 40 KTS AT 202113Z CIMSS D-PRINT: 54 KTS AT 210030Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 5-10 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE POLEWARD OTHER FACTORS: MODERATE MID-LEVEL SHEAR AND REMNANT DRY MID-LEVEL AIR ALONG THE EASTERN FLANK. ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: THE DEEP-LAYER STEERING PATTERN IS FINALLY STARTING TO EVOLVE AS PREDICTED OVER THE PAST COUPLE OF DAYS AND INDEPENDENT OF THE RECENT ERRATIC MOTION, TC 05S WILL ASSUME A SOUTHWESTWARD TRACK WITHIN THE NEXT SIX HOURS OR SO AS THE RIDGE TO THE SOUTHEAST CONTINUES TO BUILD AND ENTRENCH ITSELF JUST SOUTH OF THE GULF OF CARPENTARIA. THE RECENT MORE WESTWARD PUSH HOWEVER HAS RESULTED IN THE FORECAST TRACK MOVING A BIT MORE OFFSHORE, SKIRTING THE COAST OF MELVILLE ISLAND BY TAU 24 AND PASSING THROUGH THE CLARENCE STRAIT AND REMAINING OFFSHORE OF DARWIN THROUGH TAU 36. BY TAU 48, THE SYSTEM WILL BE MOVING INTO THE NORTHEASTERN PORTION OF THE JOSEPH BONAPARTE GULF AND WILL MAKE LANDFALL ALONG THE NORTHERN KIMBERLEY COAST AROUND TAU 96. IN TERMS OF INTENSITY, TC 05S IS ONCE MORE SHOWING THE SIGNS OF A POSSIBLE PERIOD OF INTENSIFICATION, POTENTIAL A BRIEF PERIOD OF RAPID INTENSIFICATION (RI). BASED ON THE MOST RECENT MICROWAVE IMAGERY, AND THE DRASTIC REDUCTION IN DEEP-LAYER SHEAR, THE SYSTEM APPEARS TO HAVE ACHIEVED VORTEX ALIGNMENT AND THUS SHOULD BE ABLE START INTENSIFYING QUICKLY. CLOSE PASSAGE TO, OR PASSAGE OVER, MELVILLE ISLAND WILL RESULT IN A FLATTENING OF THE INTENSIFICATION TREND OR A SLIGHT WEAKENING, BUT THE PACE WILL PICK UP AGAIN AS THE SYSTEM PASSES BY DARWIN, WITH THE SYSTEM EXPECTED TO REACH 85 KNOTS BY TAU 48. NORTHWESTERLY SHEAR IS FORECAST TO QUICKLY INCREASE AFTER TAU 48, USHERING IN AN INFLUX OF DRY AIR AS WELL, AND WILL LEAD TO A SHARP WEAKENING AS THE SYSTEM CROSSES THE BONAPARTE GULF. AFTER LANDFALL, THE SYSTEM WILL RAPIDLY DISSIPATE BY TAU 120 OVER THE KIMBERLEY COAST. MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE, WITH THE CONTINUED EXCEPTION OF GALWEM AND EGRR, REMAIN IN TIGHT AGREEMENT, THOUGH THE ENTIRE TRACK ENVELOPE HAS SHIFTED NORTHWARD DUE TO THE RECENT WESTWARD PUSH OF THE BEST TRACK. THE CONSENSUS MEMBERS ARE EVENLY SPREAD ACROSS AN ENVELOPE OF 35NM AT TAU 36, DOUBLING TO 70NM BY TAU 72. THE GEFS MEAN MARKS THE NORTHERNMOST MEMBER, WHILE THE NAVGEM IS THE SOUTHERNMOST. AFTER TAU 72, THE MODELS DISPERSE, OPENING UP THE ENVELOPE TO 380NM BY TAU 120, WITH THE ECMWF, ECEPS, GEFS AND GFS NOW INDICATING A TRACK THAT REMAINS OFFSHORE OF THE KIMBERLEY COAST FROM TAU 72 TO TAU 120, WHILE THE NAVGEM TRACKS ASHORE EAST OF WYNDHAM. THE JTWC FORECAST IS PLACED ALONG THE SOUTHERN EDGE OF THE ENVELOPE, CLOSE TO THE GFS AND GDM FGN TRACKERS THROUGH TAU 72, THEN IS GENERALLY CONSISTENT WITH THE GDM FGN THROUGH THE REMAINDER OF THE FORECAST. INTENSITY GUIDANCE CONTINUES TO SHOW HIGH UNCERTAINTY, PARTICULARLY AFTER TAU 24. THE HAFS-A AND COTC CONTINUE TO INDICATE EXTREME RI AFTER TAU 24, REACHING A PEAK BETWEEN 115-135 KNOTS BY TAU 60, WHILE THE HWRF AND CTCX WEAKEN THE SYSTEM FROM THE START OF THE FORECAST AND THE SHIPS GUIDANCE LIES IN THE MIDDLE. THE JTWC FORECAST IS POSITIONED CLOSE TO THE HAFS-A TO TAU 48, THEN FOLLOWS THE INTENSITY CONSENSUS MEAN THROUGH THE REMAINDER OF THE FORECAST PERIOD. FORECAST CONFIDENCE: TRACK 00-72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN