TC 15P(JUDY) intensifying to CAT 1 US by 24h approaching Port Vila//TC 14S(ENALA) surviving//TC 11S(FREDDY)over-land remnants//2709utc

JTWC IS ISSUING 6HOURLY WARNINGS ON TC 15P(JUDY) AND 12HOURLY WARNINGS ON TC 14S(ENALA). 3HOURLY SATELLTE BULLETINS ARE ISSUED ON 15P,14S AND ON THE OVER-LAND REMNANTS OF TC 11S(FREDDY).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) A LARGE CONSOLIDATING SYSTEM WITH DEEPENING CENTRAL CONVECTION THAT IS OFFSET NORTHWESTWARD FROM BUT ALSO OBSCURING THE LOW LEVEL CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE 270238Z AMSR2 MICROWAVE LLC FEATURE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE HIGHER END OF AGENCY AND AUTOMATED DVORAK ESTIMATES TO REFLECT THE 6-HR IMPROVEMENT. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH LIGHT TO MODERATE VWS, WARM SST, AND MODERATE RADIAL OUTFLOW.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC JUDY WILL TRACK SOUTHWESTWARD, SOUTHWARD, THEN ACCELERATE SOUTHEASTWARD AS IT ROUNDS THE WESTERN EDGE OF THE STEERING STR. THE FAVORABLE ENVIRONMENT WILL FUEL A STEADY INTENSIFICATION TO A PEAK OF 80KTS BY TAU 48. AFTERWARD, INCREASING VWS AND COOLING SST WILL GRADUALLY WEAKEN THE CYCLONE, AND BY TAU 120, WILL BE REDUCED TO 45KTS AS IT PASSES NORTHEAST OF NEW ZEALAND. CONCURRENTLY BY TAU 96, THE SYSTEM WILL BEGIN SUBTROPICAL TRANSITION AND BY TAU 120 WILL TRANSFORM INTO A SUBTROPICAL LOW.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH AN EVEN AND GRADUAL SPREAD TO 321NM BY TAU 120; HOWEVER, GIVEN THE FORMATIVE STAGE OF THE SYSTEM, THERE IS ONLY MEDIUM CONFIDENCE TO THE JTWC TRACK AND INTENSITY FORECASTS.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A DETERIORATING SYSTEM INUNDATED BY MODERATE TO STRONG NORTHWESTERLY VWS, PARTLY EXPOSING THE LOW LEVEL CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PARTLY EXPOSED LLC IN THE MSI LOOP AND LINED UP WITH A DEFINED LLC IN THE 270421Z ASCAT BULLSEYE PASS. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE ASCAT IMAGE AND OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND CONSISTENT WITH THE DETERIORATED CONVECTIVE SIGNATURE. THE ENVIRONMENT IS MARGINAL WITH THE STRONG RADIAL OUTFLOW OFFSET BY THE MODERATE TO STRONG VWS AND COOL SST.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THE FORECAST HAS BEEN EXTENDED TO TAU 72, OTHERWISE, THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC ENALA WILL LOOP COUNTER-CLOCKWISE AS THE STR TO THE WEST INITIALLY ASSUMES STEERING. AFTER TAU 48, THE STR TO THE EAST WILL ASSUME STEERING AND DRIVE THE CYCLONE SOUTHWESTWARD. THE MARGINAL ENVIRONMENT WILL SLIGHTLY WEAKEN THE SYSTEM THEN SUSTAIN IT AT ABOUT 35KTS UP TO TAU 48. AFTERWARD, DISSIPATION WILL OCCUR BY TAU 72, POSSIBLY SOONER.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL AGREEMENT WITH THE LOOPING MOTION; HOWEVER, GIVEN THE UNCERTAINTY OF THE STEERING MECHANISMS AND THE MARGINAL ENVIRONMENT, THERE IS LOW CONFIDENCE IN THE JTWC TRACK AND INTENSITY FORECASTS.