02/15UTC. INVEST 98W WAS UP-GRADED TO TD 12W AT 02/09UTC. A TROPICAL CYCLONE FORMATION ALERT WAS ISSUED AT 02/13UTC FOR INVEST 90W. INVEST 97W IS MEDIUM WHEREAS DEVELOPMENT IS STILL DEEMED UNLIKELY FOR INVEST 96W. JTWC IS ISSUING 6HOURLY WARNINGS ON 12W AND 3HOURLY SATELLITE BULLETINS ON 12W AND 90W.
TD 12W. WARNING 2 ISSUED AT 02/15UTC.THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TD 12W IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD THROUGH 24H ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE TO THE NORTH. OVER THE NEXT 24 HOURS, INVEST AREA 99W IS EXPECTED TO CONSOLIDATE AND TRACK RAPIDLY NORTHWARD, MOVING TO WITHIN 1100 KM OF TD 12W BY 24H. THEREAFTER THE TWO SYSTEMS WILL MOVE STEADILY CLOSER TO ONE ANOTHER AND TD 12W IS EXPECTED TO BE CAPTURED BY 99W BY 36H, AND BEGIN BINARY INTERACATION. TD 12W WILL BEGIN TRACKING WEST OR EVEN SOUTHWEST AFTER 36H AS IT SPIRALS STEADILY CLOSER TOWARDS 99W, ULTIMATELY MERGING WITH 99W AT OR SLIGHTLY AFTER 48H. THE UPPER-LEVEL ENVIRONMENT HAS SLOWLY IMPROVED OVER THE PAST SIX HOURS, WITH THE TUTT CELL CONTINUING TO MOVE OFF TOWARDS THE WEST, ALLOWING FOR THE SYSTEM TO TAP INTO A BIT OF DIFFLUENT OUTFLOW, RESULTING IN THE ENHANCED CONVECTIVE ACTIVTY CURRENTLY ONGOING. AS THE ORIENTATION OF THE TUTT SHIFTS SLIGHTLY OVER THE NEXT 24 HOURS, SHEAR SHOULD DECREASE TO MORE MODERATE LEVELS ALLOWING FOR A SLIGHT INTENSIFICATION THROUGH 24H. THEREAFTER, THE COMBINATION OF DISRUPTION ON THE LOW-LEVEL INFLOW PATTERN DUE TO INTERACTION WITH 99W AND THE INFLUENCE OF THE MASS CONVERGENCE ALOFT FROM THE OUTFLOW ASSOCIATED WITH THE DEVELOPMENT OF 99W, WILL SERVE TO RAPIDLY WEAKEN AND DISSIPATE TD 12W BY 48H.
TD 12W. 08/1430UTC.SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) ON THE WESTERN EDGE OF A BLOOM OF DEEP CONVECTION. A 020737UTC SSMIS 91 GHZ MICROWAVE PASS SHOWED THE SHALLOW SPIRAL BANDS WRAPPING INTO THE WELL DEFINED LLCC AND THE BEGINNINGS OF THE FLARE UP IN CONVECTION. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 021130UTC ASCAT-B SCATTEROMETER BULLSEYE WHICH SHOWED THE IMPROVED WIND FIELD, WITH 25-30 KNOT WINDS NOW EXTENDING FROM THE SOUTHERN TO NORTHWESTERN QUADRANTS AND THE HIGHEST WINDS EVIDENT IN THE NORTHEAST SECTOR. THE INITIAL INTENSITY IS ALSO ASSESSED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED ASCAT-B PASS. TD 12W LIES IN A STEADILY IMPROVING ENVIRONMENT CHARACTERIZED BY WARM SEA SURFACE TEMPERATURES (SSTS) AND MODERATE EQUATORWARD OUTFLOW, COMPETING WITH MODERATE WESTERLY VERTICAL WIND SHEAR (VWS).
TD 12W. GUIDANCE.MODEL DISCUSSION: AS WITH THE PREVIOUS FORECAST, MODEL TRACK GUIDANCE IS JUMPING VORTEXES FROM TD 12W TO INVEST 99W AFTER 48H. HOWEVER THE GUIDANCE THROUGH 48H IS IS GOOD AGREEMENT THROUGH THE DURATION OF THE CURRENT FORECAST. THE JTWC FORECAST TRACK TRACKS CLOSE TO THE PREVIOUS FORECAST AND ON THE SOUTHERN EDGE OF THE TRACK ENVELOPE THROUGH 36H. BY 48H, THE JTWC FORECAST TRACK DEVIATES TO THE SOUTH OF THE GUIDANCE ENVELOPE, WHICH DOES NOT REFLECT THE BINARY INTERACTION WTIH 99W DUE TO THE VORTEX JUMP. THE JTWC INTENSITY FORECAST LIES ABOVE THE CONSENSUS MEAN AND CLOSELY TRACKS THE HWRF SOLUTION THROUGH 24H, AND THEN DEVIATES LOWER THAN THE MAJORITY OF THE GUIDANCE THROUGH 48H AS THE SYSTEM UNDERGOES BINARY INTERACTION AND EVENTUALLY MERGES WITH 99W.
INVEST 90W. TROPICAL CYCLONE FORMATION ALERT ISSUED AT 02/13UTC.THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR 20.7N 110.4E IS NOW LOCATED NEAR 20.9N 111.8E, APPROXIMATELY 285 KM WEST-SOUTHWEST OF HONG KONG. ANIMATED ENHANCED INFRARED (EIR) IMAGERY DEPICTS FLARING CONVECTION FORMING TO THE SOUTHEAST OF A LOW LEVEL CIRCULATION CENTER (LLCC). ANIMATED RADAR IMAGERY AND A 021100UTC SSMIS 91GHZ MICROWAVE IMAGE SHOW WELL DEFINED CONVECTIVE WRAPPING FEATURE AROUND THE LLCC. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT FOR DEVELOPMENT CHARACTERIZED BY WARM (29-30C) SEA SURFACE TEMPERATURES (SST), LOW VERTICAL WIND SHEAR (VWS), AND EQUATORWARD OUTFLOW ALOFT.MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 996 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH.
INVEST 90W. GLOBAL MODELS GENERALLY AGREE THAT INVEST 90W WILL CONSOLIDATE AND STRENGTHEN AS IT TRACKS EAST- NORTHEAST ACROSS THE SOUTH CHINA SEA.
INVEST 97W.THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED NEAR 27.2N 125.1E IS NOW LOCATED NEAR 27.0N 124.8E, APPROXIMATELY 290 KM WEST-NORTHWEST OF KADENA AB. ANIMATED MSI DEPICTS AN ILL- DEFINED LOW LEVEL CIRCULATION WITH FLARING CONVECTION IN THE SOUTHERN PERIPHERY. A 020758UTC SSMIS 85GHZ MICROWAVE IMAGE REVEALS AN OVERALL LACK OF CONVECTIVE STRUCTURE ASSOCIATED WITH INVEST 97W. INVEST 97W IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT CHARACTERIZED BY POLEWARD OUTFLOW ALOFT, AND WARM (29-30C) SST OFFSET BY LOW TO MODERATE (10- 20 KT) VWS. GLOBAL MODELS GENERALLY AGREE THAT INVEST 97W WILL REMAIN QUASI-STATIONARY AS IT CONSOLIDATES AND STRENGTHENS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 996 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.
INVEST 96W.THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED NEAR 26.8N 143.4E IS NOW LOCATED NEAR 30.1N 140.8E, APPROXIMATELY 575 KM SOUTH OF YOKOSUKA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). A 022201UTC SSMIS 91GHZ MICROWAVE IMAGE REVEALS THE CONVECTION ASSOCIATED WITH THE SYSTEM IS DISPLACED TO THE SOUTH OF THE LLCC. A 020109UTC ASCAT-C PARTIAL PASS REVEALS AN ELONGATED LLCC AND 15-20 KNOT WINDS IN THE NORTHERN PERIPHERY. ANALYSIS INDICATES AN ENVIRONMENT THAT IS MARGINALLY CONDUCIVE FOR DEVELOPMENT CHARACTERIZED BY WARM (29-30C) SEA SURFACE TEMPERATURES (SST) OFFSET BY LIMITED POLEWARD OUTFLOW ALOFT, AND MODERATE (15-25 KT VERTICAL WIND SHEAR (VWS). GLOBAL MODELS AGREE THAT INVEST 96W WILL UNDERGO MINIMAL, IF ANY, CONSOLIDATION AS IT PROPAGATES NORTHWESTWARD TOWARDS JAPAN. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.
