WTXS31 PGTW 021500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 01S (DAHLIA) WARNING NR 011// RMKS/ 1. TROPICAL CYCLONE 01S (DAHLIA) WARNING NR 011 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 021200Z --- NEAR 11.2S 112.0E MOVEMENT PAST SIX HOURS - 105 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT REPEAT POSIT: 11.2S 112.0E --- FORECASTS: 12 HRS, VALID AT: 030000Z --- 12.6S 112.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 190 DEG/ 10 KTS --- 24 HRS, VALID AT: 031200Z --- 14.6S 111.8E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 195 DEG/ 12 KTS --- 36 HRS, VALID AT: 040000Z --- 16.9S 111.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 180 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 041200Z --- 17.9S 111.2E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 130 DEG/ 04 KTS --- 72 HRS, VALID AT: 051200Z --- 18.8S 112.4E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 021500Z POSITION NEAR 11.6S 112.0E. TROPICAL CYCLONE 01S (DAHLIA), LOCATED APPROXIMATELY 677 NM NORTH OF LEARMONTH, AUSTRALIA, HAS TRACKED EAST-SOUTHEASTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A RAPIDLY WEAKENING SYSTEM WITH CONVECTION NEARLY DIED OUT. THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION BASED ON A LOW REFLECTIVITY FEATURE OBSERVED IN A 021224Z 89GHZ AMSU IMAGE ALSO SHOWING A SIGNIFICANT PATCH OF DRY AIR BEGINNING TO WRAP AROUND THE SYSTEM FROM THE NORTHWEST. ANOTHER WEAK CIRCULATION CAN BE OBSERVED IN THE SATELLITE IMAGERY TO THE SOUTHWEST OF THE SYSTEM CENTER, IMPEDING THE LOW LEVEL WIND FLOW INTO TC 01S. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS WHICH IS BASED ON RECENT CURRENT INTENSITY DVORAK ESTIMATES RANGING FROM T2.0 TO 2.5 (30 TO 35 KNOTS), AND A 43 KNOT SATCON ESTIMATE FROM 021223Z. UPPER-LEVEL ANALYSIS SHOWS A RIDGE AXIS TO THE SOUTH OF THE SYSTEM WITH RELATIVELY LOW VERTICAL WIND SHEAR, MODERATE DIFFLUENCE, AND A DEGRADING EQUATORWARD OUTFLOW CHANNEL. SSTS IN THE REGION ARE CONDUCIVE FOR FURTHER DEVELOPMENT AROUND 28 TO 29 CELSIUS, HOWEVER, TEMPERATURES DECLINE SHARPLY POLEWARD OF 15 DEGREES SOUTH. COINCIDING WITH THE AFOREMENTIONED MICROWAVE IMAGE, THE CIMSS TOTAL PRECIPITABLE WATER ANIMATION SHOWS VERY DRY AIR WELL SOUTH OF THE SYSTEM WITH A BAND OF RELATIVELY DRY AIR BEGINNING TO FEED IN FROM THE NORTHWEST. TC 01S HAS TRACKED EAST-SOUTHEAST OVER THE LAST SIX HOURS AS A MID-TO-LOW LEVEL RIDGE IS BUILDING OVER THE AUSTRALIAN CONTINENT. THE RIDGE WILL BEGIN EXTENDING NORTHWARD AND STEER TC 01S TO THE SOUTH IN THE NEXT 6 TO 12 HOURS AND THIS TRACK WILL PERSIST THROUGH TAU 36. UPPER-LEVEL CONDITIONS ARE FORECAST TO IMPROVE SLIGHTLY WITH AN ANTICYCLONE DEVELOPING OVER THE SYSTEM, WHICH WILL ALLOW THE SYSTEM TO MAINTAIN TROPICAL CYCLONE STRENGTH BETWEEN 35 AND 40 KNOTS. SHORTLY AFTER TAU 48, THE SOUTHWARD TRACK WILL BRING TC 01S INTO AN INCREASINGLY UNFAVORABLE ENVIRONMENT. COOLER SSTS AND DRY AIR ENTRAINMENT WILL SIGNIFICANTLY WEAKEN THE SYSTEM, ONLY TO BE EXACERBATED BY A PASSING TROUGH INDUCING HIGH VERTICAL WIND SHEAR. THE STEERING RIDGE WILL RETROGRADE TO THE NORTHEAST AS THE PASSING TROUGH ERODES THE SOUTHERN PORTION OF THE RIDGE, CAUSING THE SYSTEM TO TURN ABRUPTLY TO THE EAST. TC 01S SHOULD FULLY DISSIPATE OVER WATER BY TAU 72. DYNAMIC MODEL GUIDANCE SHOWS FAIRLY GOOD AGREEMENT ON THE TRACK MOTION THROUGH TAU 48, BUT BEGINS TO DIVERGE THEREAFTER DUE TO THE RAPIDLY WEAKENING INTENSITY. THE FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH GOOD CONFIDENCE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 021200Z IS 12 FEET. NEXT WARNINGS AT 022100Z, 030300Z, 030900Z AND 031500Z.//