TC 05S(DARIAN): displayed a 3rd intensity peak as a CAT4 US, now embarked on a weakening trend //Invest 98B//Invest 95W// 2615utc

JTWC IS ISSUING 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 05S(DARIAN). 3HOURLY SATELLITE BULLETINS ARE ISSUED ON INVEST 98B.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TIGHTLY WRAPPED DEEP CONVECTION SURROUNDING A 19 NM DIAMETER EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A CLEAR DEPICTION OF THE EYE IN RECENT MICROWAVE SATELLITE IMAGERY, INCLUDING 260819Z AMSR2 AND 261022Z SSMIS PASSES. THE INITIAL INTENSITY OF 110 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON SUBJECTIVE DVORAK CURRENT INTENSITY ESTIMATES FROM PGTW, KNES, FMEE, AND FIMP AS WELL AS AUTOMATED INTENSITY ESTIMATES FROM UW-CIMSS INDICATING A NARROW RANGE OF POSSIBLE VALUES FROM APPROXIMATELY 102 TO 116 KNOTS. TC 05S HAS WEAKENED SLIGHTLY OVER THE PAST SIX HOURS AFTER COMPLETING A THIRD ROUND OF RAPID INTENSIFICATION TO APPROXIMATELY 115 KNOTS AT 260600Z. PASSAGE OVER A PATCH OF RELATIVELY WARMER WATER AND EXCEPTIONAL OUTFLOW BOTH POLEWARD AND TOWARD AN UPPER-LEVEL LOW SITUATED TO THE WEST AIDED THE RECENTLY OBSERVED INTENSIFICATION TREND.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 05S WILL ACCELERATE SOUTHWESTWARD IN THE NEAR TO MEDIUM TERM AS THE SUBTROPICAL STEERING RIDGE CONTINUES TO BUILD TO THE SOUTHEAST. AFTER TAU 72, THE SYSTEM WILL GRADUALLY TURN POLEWARD AS IT REACHES AND ROUNDS THE WESTERN PERIPHERY OF THE STEERING RIDGE AXIS. THE UPPER-LEVEL PATTERN IS EXPECTED TO REMAIN GENERALLY FAVORABLE THROUGH TAU 72, WITH LOW TO MODERATE VERTICAL WIND SHEAR AND SUPPORTIVE OUTFLOW. HOWEVER, THE SYSTEM WILL WEAKEN AS IT TRACKS ACROSS PROGRESSIVELY COOLER WATER. TC 05S IS EXPECTED TO CROSS THE 26C ISOTHERM WITHIN 24 HOURS. THE WEAKENING TREND WILL MODERATE IN THE EXTENDED PERIOD AS THE SYSTEM ENCOUNTERS AN UPPER-LEVEL TROUGH NEAR THE STEERING RIDGE AXIS, WHICH WILL PROVIDE BAROCLINIC ENERGY AND SUPPORT TRANSITION TO A SUBTROPICAL CYCLONE.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT REGARDING THE TRACK FORECAST, WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE. INTENSITY GUIDANCE IS ALSO IN GOOD OVERALL AGREEMENT. THERE IS SOME UNCERTAINTY IN THE RATE OF WEAKENING PRIOR TO SUBTROPICAL TRANSITION, BUT A LEVELING AROUND 40 TO 50 KNOTS IN THE EXTENDED RANGE IS HIGHLY PROBABLE.