TC 13S(DINGANI) CAT 1 US peaking within 24h//TC 11S(FREDDY ) peaked at CAT 4 US//12P(GABRIELLE) subtropical//Invest 91P//1209utc

JTWC IS ISSUING 12HOURLY WARNINGS ON TC 11S(FREDDY) AND TC 13S(DINGANI).3HOURLY SATELLITE BULLETINS ARE ISSUED ON TC 11S, TC 13S AND STS 12P(GABRIELLE).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPACT SYSTEM WITH A DEVELOPING 15NM DIAMETER EYE AND IMPROVED ORGANIZATION, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. A 120326Z MHS 89GHZ MICROWAVE IMAGE REVEALS A MICROWAVE EYE FEATURE ON THE EASTERN EDGE OF THE CORE CONVECTION WITH LIMITED CONVECTIVE BANDING DISPLACED OVER THE NORTHEAST QUADRANT. ANIMATED WATER VAPOR IMAGERY INDICATES ENHANCED POLEWARD OUTFLOW INTO A SHARP UPPER-LEVEL SHORTWAVE TROUGH AND STJ POSITIONED TO THE SOUTHWEST. THE INITIAL INTENSITY OF 65 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE KNES AND FMEE DVORAK INTENSITY ESTIMATES, CONSISTENT WITH THE VISIBLE EYE.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN FAVORABLE WITH ENHANCED POLEWARD OUTFLOW AND LOW VERTICAL WIND SHEAR (VWS) THROUGH TAU 24, CONSEQUENTLY, TROPICAL CYCLONE (TC) 13S IS EXPECTED TO INTENSIFY SLIGHTLY TO 70 KNOTS BY TAU 12 AND MAINTAIN THAT INTENSITY THROUGH TAU 24. AFTER TAU 24, TC 13S WILL WEAKEN STEADILY AS IT TRACKS SOUTHWESTWARD UNDER INCREASING VWS AND COOLING SST WITH DISSIPATION ANTICIPATED BY TAU 120.

MODEL DISCUSSION: DETERMINISTIC AND PROBABILISTIC MODEL GUIDANCE CONTINUES TO INDICATE A LARGE SPREAD IN TRACK SOLUTIONS AFTER TAU 36. THERE IS CURRENTLY A 200 TO 400NM SPREAD IN DETERMINISTIC SOLUTIONS FROM TAU 72 TO TAU 120, THEREFORE, THERE IS MEDIUM CONFIDENCE IN THE JTWC TRACK FORECAST THROUGH TAU 72 AND LOW CONFIDENCE IN THE EXTENDED PERIOD. RELIABLE INTENSITY GUIDANCE IS IN IMPROVED AGREEMENT WITH ALL MODELS INDICATING STEADY WEAKENING AFTER TAU 24. HWRF DOES PEAK SLIGHTLY HIGHER (75 KNOTS) THAN THE JTWC PEAK (70 KNOTS), WHICH IS CERTAINLY POSSIBLE, BUT SHOWS A SHARP DECREASE TO 35 KNOTS BY TAU 72. THE BULK OF THE INTENSITY GUIDANCE INDICATES DISSIPATION NEAR TAU 120.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A COMPACT SYSTEM WITH A SYMMETRICAL CENTRAL DENSE OVERCAST THAT HAS DEEPENED OVER THE LAST 12 HOURS AND MAINTAINED A SINCE-FILLED PINHOLE EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE DIMPLED EYE FEATURE IN THE MSI LOOP. THE INITIAL INTENSITY IS ALSO PLACED WITH HIGH CONFIDENCE BASED ON CLOSELY CLUSTERED AND EQUALLY ESTIMATED AGENCY DVORAK ESTIMATES AND REFLECTS THE 12-HR INTENSIFICATION. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH MODERATE TO STRONG VWS OFFSET BY WARM SST AND STRONG RADIAL OUTFLOW.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC FREDDY WILL CONTINUE ON A GENERALLY WESTWARD TO WEST-SOUTHWESTWARD TRACK UNDER THE STEERING STR. THE ENVIRONMENT WILL BECOME LESS FAVORABLE WITH THE INCURSION OF DRY AIR IN THE MID- LEVELS CAUSING A GRADUAL WEAKENING TO 75KTS BY TAU 48. AFTERWARD, THE DIMINISHING DRY AIR AND INCREASING POLEWARD OUTFLOW WILL FUEL ANOTHER RE-INTENSIFICATION PHASE, ALBEIT MORE GRADUAL, TO 90KTS BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT WITH AN EVEN AND GRADUAL SPREAD TO 222NM BY TAU 120, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. THE INTENSITY FORECAST IS AT MEDIUM CONFIDENCE FOR THE DURATION OF THE FORECAST DUE TO THE UP-AND-DOWN INTENSITY CHANGES.

THE AREA OF CONVECTION (SUBTROPICAL STORM 12P) PREVIOUSLY LOCATED NEAR 28.3S 166.3E IS NOW LOCATED NEAR 32.0S 173.3E, APPROXIMATELY 300 NM NORTH-NORTHWEST OF AUCKLAND, NEW ZEALAND. THE SYSTEM IS CURRENTLY CLASSIFIED AS A SUBTROPICAL STORM (SS), GENERALLY CHARACTERIZED AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A FULLY EXPOSED, WELL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION SHEARED OVER THE SOUTHERN SEMICIRCLE. A 120138Z AMSR2 WINDSPEED IMAGE REVEALS 55-57 KNOT WINDS ALONG THE NORTHERN COAST OF NORTH ISLAND. ADDITIONALLY, SURFACE OBSERVATIONS FROM CAPE REINGA (93004) AND MOKOHINAU (93069) INDICATE STORM-FORCE EASTERLY WINDS RANGING FROM 50 TO 61 KNOTS. THE SYSTEM IS CURRENTLY EMBEDDED UNDER STRONG UPPER-LEVEL WESTERLIES IN HIGH (30-40KT) VWS. SST IS UNFAVORABLE AT 23C. MODEL ANALYSES INDICATE MODERATE BAROCLINICITY WITH SIGNIFICANT DRY AIR ENTRAINMENT. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT SS 12P WILL TRACK SOUTHEASTWARD OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 50 TO 55 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 971 MB. FOR HAZARDS AND WARNINGS, REFERENCE THE FLEET WEATHER CENTER SAN DIEGO HIGH WINDS AND SEAS PRODUCT OR REFER TO LOCAL WMO DESIGNATED FORECAST AUTHORITY. THE POTENTIAL FOR TRANSITION INTO A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

THE AREA OF CONVECTION (INVEST 91P) PREVIOUSLY LOCATED NEAR 13.3S 137.6E IS NOW LOCATED NEAR 13.8S 138.6E, APPROXIMATELY 176 NM NORTH-NORTHWEST OF MORNINGTON ISLAND, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND RADAR IMAGERY DEPICT A BROAD, ILL-DEFINED, AND ELONGATED LOW-LEVEL CIRCULATION (LLC) WITH DISORGANIZED CONVECTION SHEARED TO THE NORTHERN SEMICIRCLE. RECENT SURFACE OBSERVATIONS INDICATE 25 KNOT WINDS ALONG THE NORTHERN AND SOUTHERN PERIPHERIES OF THE LLC. INVEST 91P IS CURRENTLY IN A MARGINALLY FAVORABLE ENVIRONMENT WITH MODERATE POLEWARD OUTFLOW ALOFT AND VERY WARM (29-30C) SST OFFSET BY STRONG (30-40KT) VWS. GLOBAL MODELS ARE IN STRONG AGREEMENT THAT 91P WILL GRADUALLY INTENSIFY AS IT DANCES AROUND THE GULF OF CARPENTARIA NEAR THE CAPE YORK PENINSULA OVER THE NEXT 48-72 HOURS BEFORE ULTIMATELY TRACKING SOUTHWARD OVERLAND. 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 REMAINS LOW.