TC 08S(BATSIRAI):re-intensifying a bit over the MOZ Channel//TC 10S(CLIFF): final warning//Invest 92P & Invest 93S: now Medium,07/06utc

JTWC IS ISSUING 12HOURLY WARNINGS ON TC 08S(BATSIRAI). WARNING 6/FINAL WAS ISSUED ON TC 10S(CLIFF) AT 06/21UTC. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 08S, 10S AND 93S.

07/02UTC.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: IN THE IMMEDIATE NEAR-TERM, TC 08S WILL CONTINUE TO DRIFT SLOWLY AS IT REMAINS IN THE COL REGION ALONG THE SUBTROPICAL RIDGE (STR) AXIS. GLOBAL MODELS ALL INDICATE THE RIDGE AXIS MOVING NORTHWARD OVER THE NEXT 12 TO 24 HOURS, AND AS THIS OCCURS, TC 08S WILL PROGRESSIVELY TAKE ON A MORE SOUTHWESTWARD TRACK. THE SYSTEM WILL ROUND THE RIDGE AXIS NO LATER THAN 24H AND BEGIN TO ACCELERATE ONTO A SOUTHEASTWARD TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD. AS THE SYSTEM MOVES FURTHER FROM LAND, IT WILL MOVE AWAY FROM THE WEDGE OF DRY AIR CURRENTLY BEING PULLED OFFSHORE AND INTO THE CORE OF THE SYSTEM, AND BECOME COCOONED IN SMALL POCKET OF MOISTURE. THE ENVIRONMENT WILL BE CONDUCIVE FOR INTENSIFICATION, WITH ENHANCED POLEWARD OUTFLOW, LOW SHEAR AND WARM (27-28C) AND THE SYSTEM IS FORECAST TO PEAK OUT AT 50 KNOTS BY 36H. THEREAFTER, INCREASING SHEAR AND DRY AIR ENTRAINMENT WILL INDUCE A WEAKENING TREND THROUGH THE REMAINDER OF THE FORECAST. THE SYSTEM WILL BEGIN SUBTROPICAL TRANSITION BY 48H AS IT STARTS TO INTERACT WITH A MID-LATITUDE TROUGH RAPIDLY APPROACHING FROM THE WEST, AND MOVES POLEWARD OF THE 26C ISOTHERM. THE SYSTEM IS FORECAST TO COMPLETE TRANSITION TO A GALE-FORCE SUBTROPICAL LOW NO LATER THAN 72H.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BROAD, RAGGED ROTATION, WITH SCATTERED, UNORGANIZED CONVECTION PRIMARILY TO THE SOUTH. A 062158Z AMSR2 37GHZ MICROWAVE IMAGE DEPICTED WEAK LOW LEVEL BANDING ON THE NORTH SIDE OF THE THE CONVECTION, WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC), AND LENT MEDIUM CONFIDENCE TO THE INITIAL POSITION. ANIMATED SHORTWAVE INFRARED IMAGERY SUGGESTS THAT THE LLCC MOVED OFFSHORE AROUND 061600Z, THEN TRACK NEARLY DUE WEST OR A BIT NORTH OF DUE WEST, BUT BASED ON THE MICROWAVE IMAGERY, APPEARS TO HAVE BECOME QUASI-STATIONARY NEAR THE INITIAL POSITION. THE INITIAL INTENSITY OF 40 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE, HEDGED HIGHER THAN A PGTW CURRENT INTENSITY ESTIMATE OF T2.0 BASED ON A BROAD SWATH OF 35-40 KNOT WINDS IN THE 062158Z AMSR2 PASSIVE MICROWAVE WIND FIELD ANALYSIS. THE SYSTEM IS DRIFTING RATHER AIMLESSLY AT THE MOMENT IN A WEAK STEERING PATTERN, AS IT APPROACHES THE SUBTROPICAL RIDGE (STR) SHEAR IS LOW AND SSTS ARE WARM, BUT OUTFLOW ALOFT IS SOMEWHAT LIMITED AND DRY AIR IS WRAPPING INTO THE CORE FROM THE EAST AND SOUTH.

MODEL DISCUSSION: TRACK GUIDANCE IS IN VERY GOOD AGREEMENT THROUGH THE FORECAST PERIOD WITH A MINIMAL SPREAD OF ABOUT 185KM AT 72H. HOWEVER IN LIGHT OF THE RATHER UNEXPECTED MOTION OVER THE PAST SIX HOURS, THERE IS ONLY MEDIUM CONFIDENCE IN THE FORECAST TRACK AS THE TRACK MOTION OVER THE NEXT 12 HOURS WILL HAVE A LARGE IMPACT ON THE ULTIMATE TRACK DIRECTION AND SPEED. INTENSITY GUIDANCE IS IN GOOD AGREEMENT THROUGH THE FORECAST PERIOD, AND SUPPORTS THE INTENSIFICATION THROUGH 36H FOLLOWED BY STEADY WEAKENING THROUGH THE SUBTROPICAL TRANSITION. THE JTWC FORECAST LIES ABOUT FIVE KNOTS ABOVE THE CONSENSUS MEAN THROUGH TAU 36 THEN TRACKS THE CONSENSUS MEAN THEREAFTER WITH MEDIUM CONFIDENCE.

062100Z POSITION NEAR 23.3S 78.2E. 06FEB22. TROPICAL CYCLONE 10S (CLIFF), LOCATED APPROXIMATELY 1900 KM SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 17 KM/H OVER THE PAST SIX HOURS. ANIMATED SHORTWAVE INFRARED SATELLITE IMAGERY DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC), WHICH IS DEVOID OF ANY SIGNIFICANT CONVECTION. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON A 061705Z MODIS TERRA INFRARED IMAGE, WHICH ELIMINATED THE LIMB ISSUES ASSOCIATED WITH THE METEOSAT-8 AND HIMWARI-8 IMAGERY. THE INITIAL INTENSITY IS SET WITH LOW CONFIDENCE AT A GENEROUS 35 KNOTS, IN LINE WITH EARLIER ASCAT DATA AND THE ADT ESTIMATE. THE SYSTEM IS TRACKING WEST-SOUTHWESTWARD ALONG THE NORTHERN SIDE OF A DEEP SUBTROPICAL RIDGE (STR) TO THE SOUTH. TC 10S IS STEADILY WEAKENING AS IT SPINS DOWN, HAVING BEEN OVERWHELMED BY DRY AIR AND STRONG VERTICAL WINDS SHEAR. THE SYSTEM IS EXPECTED TO WEAKEN TO 30 KNOTS WITHIN THE NEXT 12 HOURS. THE REMNANT CIRCULATION IS EXPECTED TO CONTINUE TRACKING WESTWARD FOR SEVERAL DAYS AFTER DIPPING BELOW THE 35 KNOT WARNING THRESHOLD. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI.

THE AREA OF CONVECTION (INVEST 92P) PREVIOUSLY LOCATED NEAR 18.4S 160.0E IS NOW LOCATED NEAR 19.7S 165.9E, APPROXIMATELY 330KM SOUTHWEST OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A SLOWLY-CONSOLIDATING, PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH FORMATIVE BANDING OVER THE NORTHERN SEMICIRCLE AND FLARING DEEP CONVECTION OBSCURING THE CENTER. A 070233Z ATMS 88.2GHZ MICROWAVE IMAGE REVEALS SHALLOW BANDING WRAPPING INTO A DEFINED CENTER WITH LIMITED DEEP CONVECTIVE BANDING OVER THE NORTHERN QUADRANT. UPPER-ANALYSIS REVEALS A POINT SOURCE TO THE SOUTHEAST, WHICH IS PRODUCING VIGOROUS EQUATORWARD OUTFLOW BUT MODERATE TO HIGH (20-30 KNOTS) VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES ARE FAVORABLE AT 28-29C. OVER THE NEXT TWO DAYS, GLOBAL MODELS SHOW AN INITIAL SOUTHEASTWARD TRACK THEN QUASI-STATIONARY PERIOD EAST OF NEW CALEDONIA WITH STEADY INTENSIFICATION AND DEVELOPMENT OF AN EXTENSIVE SWATH OF GALE-FORCE WINDS OVER THE EASTERN SEMICIRCLE. THIS REGION WILL BE MONITORED CLOSELY AS THE GLOBAL MODELS INDICATE ANOTHER TROPICAL DISTURBANCE DEVELOPING NEAR FIJI DURING THE NEXT TWO DAYS WITHIN THE SOUTH PACIFIC CONVERGENCE ZONE (SPCZ), WHICH EXTENDS EAST INTO THE TONGA AREA (THIS MAY PRODUCE SIGNIFICANT RAINFALL OVER THE TONGA REGION). MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

AN AREA OF CONVECTION (INVEST 93S) HAS PERSISTED NEAR 10.5S 105.1E, APPROXIMATELY 50 KM WEST OF CHRISTMAS ISLAND. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS AN EXPOSED, WELL-DEFINED LOW LEVEL CIRCULATION WITH PERSISTENT, DISORGANIZED DEEP CONVECTION IN THE SOUTHWESTERN SECTOR. A 070159Z METOP-B IMAGE REVEALS A CONSOLIDATING WIND FIELD WITH 25-30KT WINDS IN THE SOUTHWESTERN AND NORTHEASTERN QUADRANTS. OVER THE PAST 24 HOURS, CHRISTMAS ISLAND IS REPORTING INCREASING NORTHERLY SURFACE WINDS, CURRENTLY 15KTS SUSTAINED GUSTING TO 25KTS, WITH A 2 MB SEA LEVEL PRESSURE DROP. ENVIRONMENTAL ANALYSIS INDICATES THE INVEST IS IN A MARGINALLY FAVORABLE ENVIRONMENT WITH FAIR POLEWARD OUTFLOW AND HIGH (29-30C) SEA SURFACE TEMPERATURES OFFSET BY HIGH (30-40KT) VWS. ALTHOUGH GLOBAL MODELS INDICATE A SOUTHWARD TRACK AND SLOW DEVELOPMENT AS THE UPPER-LEVEL ENVIRONMENT IMPROVES OVER THE NEXT TWO DAYS, INVEST 93S IS A COMPACT, WELL-DEFINED AND SHALLOW SYSTEM WHICH MAY NOT BE RESOLVED WELL BY THE GLOBAL MODELS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.