WTXS31 PGTW 041500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 03S (AVA) WARNING NR 008// RMKS/ 1. TROPICAL CYCLONE 03S (AVA) WARNING NR 008 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 041200Z --- NEAR 17.4S 51.4E MOVEMENT PAST SIX HOURS - 260 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 025 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 - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 17.4S 51.4E --- FORECASTS: 12 HRS, VALID AT: 050000Z --- 17.6S 50.3E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 235 DEG/ 04 KTS --- 24 HRS, VALID AT: 051200Z --- 18.1S 49.6E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 205 DEG/ 06 KTS --- 36 HRS, VALID AT: 060000Z --- 19.1S 49.1E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 185 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 190 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 061200Z --- 20.4S 48.9E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 185 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 180 DEG/ 07 KTS --- 72 HRS, VALID AT: 071200Z --- 23.0S 48.9E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 095 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 220 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 200 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 081200Z --- 24.9S 48.2E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 205 DEG/ 04 KTS --- 120 HRS, VALID AT: 091200Z --- 26.4S 47.4E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 135 NM NORTHEAST QUADRANT 135 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT --- REMARKS: 041500Z POSITION NEAR 17.5S 51.1E. TROPICAL CYCLONE 03S (AVA), LOCATED APPROXIMATELY 289 NM NORTHWEST OF ST DENIS, REUNION, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL (MSI) SATELLITE IMAGERY DEPICTS BANDING WRAPPING INTO AN ORGANIZED LOW LEVEL CIRCULATION CENTER (LLCC), WHICH IS COVERED BY A FLARING CENTRAL DENSE OVERCAST WITH AN INFLOW NOTCH TO THE NORTHWEST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 041142Z 89GHZ SSMI MICROWAVE IMAGE SHOWING DEEP CONVECTION PREDOMINANTLY TO THE NORTHEAST OF THE LLCC AND LOW LEVEL CURVED BANDING WRAPPING INTO THE LLCC. THE INITIAL INTENSITY OF 55 KNOTS IS BASED ON DVORAK ESTIMATES OF T3.5 (55 KNOTS) FROM ALL AGENCIES. ENVIRONMENTAL ANALYSIS REVEALS A MODERATELY FAVORABLE ENVIRONMENT WITH LOW (10 TO 15 KNOT) VERTICAL WIND SHEAR (VWS) AND WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES. UPPER LEVEL ANALYSIS SHOWS THE SYSTEM HAS MODERATE EQUATORWARD AND POLEWARD OUTFLOW CHANNELS, FUELING DEEP CONVECTION. TC 03S IS FORECAST TO CONTINUE TO TRACK WESTWARD THEN SOUTHWESTWARD TOWARD MADAGASCAR THROUGH TAU 24, BEING BLOCKED BY A BUILDING SUB-TROPICAL RIDGE (STR) LOCATED TO THE SOUTH. AFTER TAU 24, AS THE STR MOVES EASTWARD, THE SYSTEM WILL TRACK GENERALLY SOUTHWARD ALONG THE WESTERN PERIPHERY OF THE STR, TAKING IT DOWN THE EAST COAST OF MADAGASCAR. TC 03S IS FORECAST TO REACH A PEAK INTENSITY OF 70 KNOTS BY TAU 24. AFTER TAU 24, CONTINUED LAND INTERACTION BETWEEN THE WESTERN HALF OF TC 03S AND MADAGASCAR WILL PREVENT FURTHER INTENSIFICATION. AFTER TAU 48, THE SYSTEM WILL GAIN SLIGHTLY MORE SEPARATION FROM LAND AND BE ABLE TO MAINTAIN AROUND 65 KNOTS INTENSITY THROUGH TAU 96. AFTER TAU 96, DECREASING SEA SURFACE TEMPERATURES AND INCREASING VERTICAL WIND SHEAR WILL BEGIN TO WEAKEN TC 03S. A LONGWAVE TROUGH MOVING THROUGH THE AREA AROUND TAU 120 HAS THE POTENTIAL TO IMPROVE POLEWARD OUTFLOW, BUT WILL ALSO BRING COLD TEMPERATURE ADVECTION AND INCREASED VERTICAL WIND SHEAR UNFAVORABLE FOR SUSTAINING INTENSITIES OVER 60 KTS PAST THE END OF THE FORECAST PERIOD. AT LATER TAUS, THE STR WILL BUILD BACK WESTWARD, SHIFTING THE TRACK SLIGHTLY WESTWARD. AT THIS TIME IT IS UNCLEAR WHETHER THE PASSING TROUGH WILL REACH SUFFICIENTLY EQUATORWARD ENOUGH TO BREAK THE BUILDING RIDGE MAKING THE EXTENDED TRACK BEYOND TAU 120 UNCERTAIN. DYNAMIC MODEL GUIDANCE SHOWS RELATIVELY GOOD AGREEMENT THROUGH TAU 72. AFTERWARD, SOLUTIONS BEGIN TO SPREAD SIGNIFICANTLY IN BOTH SPEED AND DIRECTION RELATED TO THE COMPLEX TROUGH AND SHIFTING RIDGE INTERACTION. NOTABLE MODEL OUTLIERS ARE THE NAVGEM AND JGSM SOLUTIONS SHOWING A MUCH MORE PRONOUNCED SOUTHWARD TURN OCCURRING SOONER AND FURTHER EAST AS A RESULT OF A NEAR-EQUATORIAL RIDGE EXERTING MORE INFLUENCE OVER STEERING. NAVGEM AND THE GFS ENSEMBLE AT LATER TAUS EXHIBIT A DRAMATIC TURN TO THE WEST, OVERLAND MADAGASCAR, DUE TO THE STRENGTHENING STR TO THE EAST. DUE TO THE LARGE SPREAD IN MODEL GUIDANCE, THERE IS OVERALL LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 041200Z IS 17 FEET. NEXT WARNINGS AT 042100Z, 050300Z, 050900Z AND 051500Z.//