TC 14S(VERNON) over improved OHC// Over-land TC 15S(ANIKA): Tropical Cyclone Formation Alert//Invests 94P & 95S, 01/03utc

JTWC IS ISSUING 12HOURLY WARNINGS ON TC 14S(VERNON). 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 14S, OVER-LAND TC 15S , INVEST 94P AND INVEST 95S.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 14S WILL CONTINUE GENERALLY SOUTH-SOUTHWESTWARD UNDER THE INFLUENCE OF THE SUBTROPICAL RIDGE TO THE SOUTHEAST. THE SYSTEM IS EXPECTED TO CONTINUE THIS DIRECTION FOR THE REMAINDER OF THE FORECAST PERIOD. OVER THE NEXT 24 HOURS, AS TC 14S MOVES AWAY FROM THE POOL OF LOW OCEAN HEAT CONTENT, IT MOVES INTO WARMER WATERS AND INCREASES SLIGHTLY IN INTENSITY. AROUND 36H, THE SYSTEM WILL REACH 55 KTS AND REMAIN AROUND THAT INTENSITY UNTIL 72H. BY THIS TIME, TC 14S WILL BEGIN SUBTROPICAL TRANSITION AS IT BEGINS TO EXPERIENCE HIGHER WIND SHEAR AND COOLER SEA SURFACE TEMPERATURES AS IT MOVES FARTHER SOUTH. IT IS EXPECTED TO COMPLETE SUBTROPICAL TRANSITION BY 96H.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAGGED CIRCULATION WITH CONVECTION BEING SHEARED TO THE SOUTHEAST. A 282211Z SSMIS 91GHZ IMAGE DEPICTS A SYSTEM WITH FRAGMENTED CONVECTION ON THE SOUTHERN SIDE OF THE CIRCULATION. THE INITIAL POSITION IS BASED ON AN EXTRAPOLATION FROM THE CENTER OF THE LOW LEVEL BANDING IN THE PREVIOUSLY MENTIONED SSMIS IMAGE. THE INITIAL INTENSITY OF 45 KTS IS HEDGED SLIGHTLY LOWER THAN AGENCY DVORAK CURRENT INTENSITY ESTIMATES BASED ON AN OBSERVED WEAKENING TREND IN THE DT AND ALSO SEEN IN THE RAW ADT. TC 14S IS CURRENTLY IN A MARGINAL ENVIRONMENT CHARACTERIZED BY MODERATE VERTICAL WIND SHEAR AND LOW OCEAN HEAT CONTENT DUE TO THE SYSTEM PASSING OVER ITS PREVIOUS TRACK.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT IN REGARDS TO TRACK FORECAST WITH ALL MODELS INDICATING A GENERALLY SOUTH-SOUTHWESTWARD TRACK FOR THE REMAINDER OF THE FORECAST PERIOD, BUT THERE IS A 425 KM CROSS-TRACK SPREAD AT 96H. THE JTWC FORECAST TRACK IS PLACED SLIGHTLY WEST OF CONSENSUS, FAVORING THE GFS AND ECMWF MODEL TRACKS. INTENSITY GUIDANCE IS IN GOOD AGREEMENT WITH ALL MODELS INDICATING MODERATE INTENSIFICATION TO ABOUT 55-60 KTS PEAKING AROUND 60H, AND THEN FOLLOWED BY A GRADUAL WEAKENING TREND AS THE SYSTEM MOVES SOUTH.

FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 110 NM EITHER SIDE OF A LINE FROM 17.5S 123.5E TO 18.5S 121.2E WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT IMAGERY AT 010000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 17.6S 123.3E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 19 KM/H. 2. REMARKS: THE AREA OF CONVECTION (REMNANTS OF TC 15S) PREVIOUSLY LOCATED NEAR 16.5S 125.0E IS NOW LOCATED NEAR 17.6S 123.3E, APPROXIMATELY 570 KM WEST-SOUTHWEST OF WYNDHAM. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY AND A 282216Z 91GHZ IMAGE DEPICT BROAD CONVECTION OVERHEAD A LOW LEVEL CIRCULATION (LLC) THAT IS CURRENTLY OVER LAND. ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS FOR DEVELOPMENT DEFINED BY ROBUST OUTFLOW ALOFT, LOW TO MODERATE (15-20KT) VERTICAL WIND SHEAR, AND THE POTENTIAL FOR WARM (29-30C) SEA SURFACE TEMPERATURES ONCE THE CENTER MOVES BACK OVER WATER. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT TC 15S WILL TRACK WESTWARD ALONG THE NORTHWESTERN COAST OF AUSTRALIA BEFORE EMERGING OVER THE INDIAN OCEAN AROUND 18H AND THEN REACH WARNING CRITERIA. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.

GLOBAL MODELS ARE IN GOOD AGREEMENT THAT TC 15S WILL TRACK WESTWARD ALONG THE NORTHWESTERN COAST OF AUSTRALIA BEFORE EMERGING OVER THE INDIAN OCEAN AROUND 18H AND THEN REACH WARNING CRITERIA.

AN AREA OF CONVECTION (INVEST 95S) HAS PERSISTED NEAR 10.4S 109.9E, APPROXIMATELY 450 KM EAST OF CHRISTMAS ISLAND. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 281358Z ASCAT B PASS DEPICT A WEAK BUT WELL DEFINED LOW LEVEL CIRCULATION WITH WINDS OF 15 KNOTS NEAR THE CENTER. ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY FAVORABLE CONDITIONS FOR DEVELOPMENT WITH POLEWARD OUTFLOW ALOFT AND WARM (29-30C) SEA SURFACE TEMPERATURES; OFFSET BY MODERATE TO HIGH (20-25KT) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN AGREEMENT THAT 95S WILL HAVE LITTLE DEVELOPMENT AS IS SLOWLY TRACKS SOUTHEASTWARD OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO LOW.

GLOBAL MODELS ARE IN AGREEMENT THAT 95S WILL HAVE LITTLE DEVELOPMENT AS IS SLOWLY TRACKS SOUTHEASTWARD OVER THE NEXT 24-48 HOURS.