WTPS32 PGTW 040900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 17P (IRIS) WARNING NR 021 02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 040600Z --- NEAR 19.3S 151.0E MOVEMENT PAST SIX HOURS - 100 DEGREES AT 05 KTS POSITION ACCURATE TO WITHIN 015 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 145 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT REPEAT POSIT: 19.3S 151.0E --- FORECASTS: 12 HRS, VALID AT: 041800Z --- 19.4S 151.3E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 110 DEG/ 02 KTS --- 24 HRS, VALID AT: 050600Z --- 19.5S 151.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 120 DEG/ 01 KTS --- 36 HRS, VALID AT: 051800Z --- 19.6S 151.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 270 DEG/ 02 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 060600Z --- 19.6S 151.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 295 DEG/ 01 KTS --- 72 HRS, VALID AT: 070600Z --- 19.4S 150.9E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 040900Z POSITION NEAR 19.3S 151.1E. TROPICAL CYCLONE 17P (IRIS), LOCATED APPROXIMATELY 330 NM EAST- SOUTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED EASTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MSI SHOWS A MOSTLY-EXPOSED LLC WITH THE CENTRAL CONVECTION CONTINUING TO BE DISPLACED SOUTHWARD. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE VISIBLE LLC IN THE MSI LOOP THAT LINED UP WELL WITH A DEFINED LOW REFLECTIVITY CIRCULATION FEATURE IN THE 040435Z SSMIS MICROWAVE PASS. THE INITIAL INTENSITY IS BASED ON AN OVERALL ASSESSMENT OF AGENCY DVORAK ESTIMATES AND REFLECTS THE SUSTAINED CONVECTIVE SIGNATURE OF TC 17P. UPPER LEVEL ANALYSIS INDICATES THAT THE CYCLONE IS IN AN AREA OF MODERATE (15-20 KNOT) VWS THAT IS MOSTLY OFFSET BY AN EXCELLENT POLEWARD OUTFLOW. ALONG-TRACK SSTS AT 29C ARE ALSO CONDUCIVE. THE SYSTEM IS TRACKING SLOWLY INTO A COL ALONG THE SOUTHWESTERN PERIPHERY OF A WEAKENING NER TO THE NORTHEAST. IRIS IS EXPECTED TO ENTER INTO A QUASI-STATIONARY STATE IN THE COL BETWEEN THE NER AND THE STR TO THE SOUTHWEST. DURING THIS PHASE, THE CYCLONE WILL SLOWLY RECURVE NORTHWESTWARD AS THE STR EVENTUALLY DOMINATES AS THE PRIMARY STEERING MECHANISM. TC 17P IS FORECAST TO GRADUALLY WEAKEN AS VWS INCREASES. ADDITIONALLY, A MID-LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST WILL CAUSE SUBSIDENCE AND STEADILY ERODE THE ASSOCIATED CONVECTION. AVAILABLE NUMERICAL MODEL GUIDANCE REMAINS SIGNIFICANTLY SPREAD AND TRIFURCATED WITH COAMPS AND NAVGEM SOLUTIONS TRACKING TC 17P EASTWARD, SEVERAL MODELS INCLUDING GFS AND ECMWF RECURVING IT EQUATORWARD, AND THE HWRF PREDICTING A WESTWARD TRACK. IN VIEW OF THIS, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID SLIGHTLY SLOWER AND WESTWARD OF MODEL CONSENSUS TO OFFSET THE EASTWARD OUTLYING TRACKS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 040600Z IS 14 FEET. NEXT WARNINGS AT 041500Z, 042100Z, 050300Z, AND 050900Z.//