WDPS31 PGTW 280900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 15P (JUDY) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 14.6S 168.3E INITIAL INTENSITY: 65 KTS GEOGRAPHIC REFERENCE: 186 NM NORTH OF PORT VILA, VANUATU MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 07 KTS SIGNIFICANT WAVE HEIGHT: 22 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FAIRLY SYMMETRICAL SYSTEM WITH THICK CONVECTIVE BANDS WRAPPING INTO AN ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC). THE ABOVE MSI ALSO REVEALS HINTS OF AN EYE TRYING TO MAKE ITS PRESENCE KNOWN. ANALYSIS OF THE 280457Z SSMIS 91GHZ AND THE 280249Z ATMS 183GHZ IMAGES INDICATE A MICROWAVE EYE IS NOW TAKING SHAPE, FURTHER INDICATING THE SYSTEM IS INTENSIFYING AND BECOMING BETTER ORGANIZED. ENVIRONMENTAL ANALYSIS INDICATES TC JUDY TO BE IN FAVORABLE CONDITIONS FOR CONTINUAL TROPICAL DEVELOPMENT. THESE CONDITIONS ARE CHARACTERIZED BY CONSISTENT POLEWARD OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), A STRONG 850 MB VORTICITY SIGNATURE, AND VERY WARM (30-31 C) SEA SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED MSI, MICROWAVE IMAGERY AND SURFACE OBSERVATIONS FROM SOLA (VANUA LAVA) AND SARATMATA WHICH INDICATE AN ABRUPT CHANGE IN WIND DIRECTION FROM EASTWARD TO WESTWARD RESPECTIVELY OVER APPROXIMATELY A 65 NM SPAN. THE INITIAL INTENSITY OF 65 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON PREVIOUS MULTI-AGENCY AND AUTOMATED DVORAK ESTIMATES. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS KNES: T3.5 - 55 KTS PHFO: T4.5 - 77 KTS CIMSS SATCON: 60 KTS AT 280245Z CIMSS ADT: 59 KTS AT 280730Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 30-31 CELSIUS OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC JUDY CONTINUES ITS SOUTHWARD TRACK AS IT CROSSES THE STR AXIS TO THE EAST. AFTER TAU 12, THE SYSTEM WILL SHIFT SOUTH-SOUTHEASTWARD AND INCREASE IN INTENSITY TO 85 KNOTS. TC JUDY WILL MAINTAIN THIS INTENSITY AS IT MAKES A FURTHER SHIFT SOUTHEASTWARD BY TAU 24. BY TAU 36, TC 15P WILL PICK-UP IN TRACK SPEED AND DECREASE IN INTENSITY TO 80 KNOTS AS IT WILL BEGIN TO ENTER A MORE HOSTILE ENVIRONMENT CHARACTERIZED BY STRONGER VWS AND CONTINUAL DRY AIR FROM THE WEST BEING WRAPPED INTO THE SYSTEM. BY TAU 72, TC JUDY WILL CROSS OVER RELATIVELY COOLER (25-26 C) SSTS AND BEGIN TO MAKE ITS TRANSITION TO A SUBTROPICAL SYSTEM. BY TAU 96, TC 15P WILL BECOME FULLY SUBTROPICAL. MODEL DISCUSSION: THE JTWC TRACK CONSENSUS MEMBERS ARE IN RELATIVELY GOOD AGREEMENT WITH A CONTINUAL SOUTHWARD TRACK, FOLLOWED BY A SOUTHEASTWARD TRACK. THE FORECAST MODEL ENVELOPE HAS A 95 NM SPREAD BY TAU 24 WHICH SLIGHTLY INCREASES TO 105 NM BY TAU 96. BECAUSE THIS THIS, THE JTWC FORECAST TRACK TO SET WITH HIGH CONFIDENCE. THE JTWC INTENSITY CONSENSUS MEMBERS ARE ALSO IN GOOD AGREEMENT SHOWING AN INCREASE IN INTENSITY UP TO TAUS 24 AND 36, THEN A GRADUAL DECREASE THROUGHOUT THE FORECAST PERIOD. RAPID INTENSIFICATION MODEL GUIDANCE DID TRIGGER, HOWEVER THE COAMPS-TC INTENSITY GUIDANCE DID NOT SHOW ANY INDICATIONS OF RI DURING THIS FORECAST PERIOD. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN