WDPS31 PGTW 061500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 30P (MAILA) WARNING NR 007// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 9.7S 155.5E INITIAL INTENSITY: 95 KTS GEOGRAPHIC REFERENCE: 712 NM NORTHEAST OF CAIRNS, AUSTRALIA MOVEMENT PAST 6 HOURS: EASTWARD AT 02 KTS SIGNIFICANT WAVE HEIGHT: 32 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A COMPACT, SYMMETRICAL SYSTEM MEANDERING SLOWLY ABOUT THE NORTHERN SOLOMON SEA. CONVECTIVE HOT TOWER ACTIVITY HAS DECREASED OVER THE PAST SIX HOURS, AND THE DEEPEST CONVECTION REMAINS FIRMLY ENTRENCHED ALONG THE WESTERN THROUGH NORTHERN QUADRANTS OF THE CIRCULATION. PERSISTENT EASTERLY WIND SHEAR, WITH INDICATIONS OF HIGHER MID-LEVEL SHEAR, IS KEEPING THE CONVECTION FROM FULLY WRAPPING UPSHEAR ON THE EASTERN SIDE OF THE CIRCULATION, OR FROM PERSISTING THERE IF IT DOES MANAGE TO WRAP. WHILE THE EYE IN THE EIR IS FLEETING AND TRANSIENT, IN THE LOWER LEVELS IT IS VERY WELL-FORMED AS DEPICTED IN A 060800Z RCM-3 SAR PASS AS WELL AS A 061301Z GMI COLOR-ENHANCED 37GHZ MICROWAVE IMAGE. THE MICROWAVE IMAGE REVEALS A SOLID WESTERN EYEWALL WITH A MUCH WEAKER EASTERN EYEWALL. THE SAR DATA REVEALED A VERY SYMMETRICAL EYE OF ABOUT 18NM IN DIAMETER, WITH A MEAN VMAX OF 92 KNOTS. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON AN EXTRAPOLATION BETWEEN THE GMI MICROWAVE EYE AND THE SAR EYE FEATURE. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON A BLEND OF THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES NOTED BELOW, SUPPORTED BY THE SAR VMAX DATA. ENVIRONMENTAL CONDITIONS REMAIN OVERALL FAVORABLE, HOWEVER THE MID-LEVEL SHEAR IS IN THE NEGATIVE COLUMN AND THE LATEST SST AND OHC ANALYSES INDICATE COOLER WATERS ARE BEGINNING TO REACH THE SURFACE, A LARGE INHIBITING FACTOR. INITIAL WIND RADII BASIS: SCATTEROMETER AND SAR DATA. CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN, WITH STRONG WEST-NORTHWEST GRADIENT FLOW JUST SOUTH OF EQUATOR AND A DEEP LAYER SUBTROPICAL RIDGE (STR) OVER NORTHERN AUSTRALIA. THE WESTERLY GRADIENT FLOW IS CURRENTLY ASSESSED AS SLIGHTLY PREDOMINATE. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS KNES: T6.0 - 115 KTS ABRF: T5.5 - 102 KTS CIMSS ADT: 65 KTS AT 061150Z CIMSS AIDT: 75 KTS AT 061150Z CIMSS D-MINT: 90 KTS AT 060734Z CIMSS D-PRINT: 89 KTS AT 061230Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE WESTWARD OTHER FACTORS: UPWELLING OF COOL OCEANIC WATERS. ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: HIGH 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 30P (MAILA) CONTINUES TO MEANDER SLOWLY EASTWARD, ENSCONCED IN A COMPETING STEERING PATTERN. FOR THE MOMENT, THE WESTERLY GRADIENT FLOW ALONG THE EQUATOR APPEARS TO HAVE THE SLIGHT UPPER-HAND AND IS INFLUENCING TC 30P EASTWARD. OVER THE NEXT 24 TO 36 HOURS, THE GRADIENT IS EXPECTED TO WEAKEN, ALLOWING TC 30P TO PERFORM A SLOW LOOP NORTH TO THE NORTH-NORTHWEST. BY TAU 48, RIDGING WILL BUILD IN FROM THE EAST AFTER PASSAGE OF TC 31P TO THE SOUTH, WHILE SIMULTANEOUSLY THE STR OVER AUSTRALIA MOVES EASTWARD WHILE BUILDING INTO THE CORAL SEA. THESE PATTERN CHANGES WILL KICK THE SYSTEM WESTWARD. THROUGH TAU 72, THE STR TO THE SOUTH CONTINUES TO STRENGTHEN AND MOVE EASTWARD, PUSHING TC 30P ONTO A WEST-SOUTHWEST TRAJECTORY THROUGH THE REMAINDER OF THE FORECAST PERIOD. THE SYSTEM IS EXPECTED TO CLIP THE SOUTHEASTERN TIP OF PAPUA NEW GUINEA, PASSING OVER THE EASTERN APPROACHES TO THE MILNE BAY PRIOR TO TAU 96. THE SYSTEM THEN MOVES INTO THE NORTHERN CORAL SEA BY TAU 120. REGARDING INTENSITY, A PEAK INTENSITY OF 100-105 KNOTS IS FORECAST BY TAU 12, BEFORE SIGNIFICANTLY COOLER WATERS UPWELL TO THE SURFACE AND CUT OFF THE ENERGY SOURCE FOR THE SYSTEM. A FAIRLY RAPID WEAKENING PHASE BEGINS IMMEDIATELY AFTER TAU 12, REDUCING THE SYSTEM TO 75 KNOTS OR POTENTIALLY LOWER BY TAU 48. BY TAU 48, TC 30P WILL BE FAR ENOUGH AWAY FROM THE UPWELLED COLD POOL TO REINTENSIFY. THE FORECAST CALLS FOR A SECOND PEAK OF 90 KNOTS, BUT HOW STRONG THE SYSTEM GETS DURING THIS REINTENSIFICATION PHASE DEPENDS ON HOW WEAK IT GETS DURING THE WEAKENING PHASE. AS THE SYSTEM APPROACHES MILNE BAY, DISRUPTION OF THE LOW-LEVEL INFLOW THROUGH TERRAIN INTERACTIONS WILL SEVERELY DISRUPT THE CORE AND WEAKEN THE SYSTEM AS IT CROSSES THE PENINSULA. THROUGH THE FINAL HOURS OF THE FORECAST, TC 30P IS LIKELY TO ATTEMPT ANOTHER ROUND OF INTENSIFICATION BUT DRY AIR ENTRAINMENT, REDUCED OUTFLOW ALOFT AND MODERATE SHEAR WILL INHIBIT SIGNIFICANT REINTENSIFICATION. MODEL DISCUSSION: TRACK GUIDANCE CONTINUES TO IMPROVE IN TERMS OF OVERALL AGREEMENT WITH THE TRACK SCENARIO. THROUGH TAU 48, THE CONSENSUS PACKAGE, WITH THE EXCEPTION OF THE AI MODELS AND THE NAVGEM, AGREE ON A EASTWARD TRACK WHICH TURNS SLOWLY BUT SHARPLY IN A COUNTER-CLOCKWISE LOOP. WITH THE EXCEPTIONS NOTED ABOVE, THE REMAINDER OF THE GUIDANCE IS VERY TIGHTLY PACKED, LENDING MEDIUM TO HIGH CONFIDENCE THROUGH THIS POINT IN THE FORECAST. BY TAU 72, THE PREVIOUSLY MENTIONED OUTLIERS BEGIN TO MAKE AN ATTEMPT TO REJOIN THE PACK BUT ARE STILL OUTLIERS TO THE NORTH. THE REMAINDER OF THE PACKAGE IS STILL TIGHTLY CONSTRAINED IN A 60NM WIDE ENVELOPE THAT PRESENTING A SOUTHWESTWARD TRAJECTORY. ALONG-TRACK SPREAD BEGINS TO INCREASE BY TAU 72, WITH THE ECWMF BEING THE FASTEST MODEL AND THE NAVGEM THE SLOWEST. BY TAU 120, CROSS-TRACK SPREAD INCREASES TO ABOUT 200NM, BETWEEN THE FNV3 ON THE NORTH SIDE AND NAVGEM ON THE SOUTH SIDE OF THE ENVELOPE. MORE SIGNIFICANT IS THE INCREASING ALONG-TRACK SPREAD, WHICH INCREASES TO MORE THAN 300NM BY TAU 120 WITH ECMWF CONTINUING TO OUTPACE ALL THE OTHER MODELS. THE AI MODELS (AICN AND EC-AIFS IN PARTICULAR) ARE SIGNIFICANT OUTLIERS IN THE EXTENDED FORECAST, TRACKING THE SYSTEM FURTHER EQUATORWARD THROUGH THE END OF THE FORECAST. THE JTWC FORECAST IS PLACED NEAR, AND SLIGHTLY FASTER, THAN THE CONSENSUS MEAN FROM TAU 72 TO 120, WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE IS SPLIT INTO TWO CAMPS, THE COUPLED AND THE UNCOUPLED MODELS. IN THIS FORECAST, THE COUPLED MODELS HAVE THE UPPER-HAND, AND INDICATE A FLAT INTENSITY THROUGH TAU 12, THEN RAPID WEAKENING, BOTTOMING OUT BETWEEN 70-75 KNOTS BY TAU 36 BEFORE RAPIDLY RECOVERING AND REINTENSIFYING TO A PEAK BETWEEN 85-95 KNOTS BY TAU 72. THEREAFTER THE TWO CAMPS REJOIN AND AGREE ON A SLOW WEAKENING TREND THROUGH TAU 120. THE JTWC FORECAST IS PLACED NEAR THE HAFS-A GUIDANCE, ESPECIALLY AFTER TAU 24. FORECAST CONFIDENCE: TRACK 00-72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN