Powerful and compact TC 04S(CHIDO) tracked over AGALEGA islands now peaking at Super Typhoon Intensity//1209utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 04S(CHIDO). 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 90B AND 93S.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 04S (CHIDO) HAS BEEN OBSERVED TO UNDERGO EXTREME RAPID INTENSIFICATION OVER THE PREVIOUS 24 HOURS, INCREASING FROM AN INTENSITY OF 75 KTS TO 135 KTS OVER THE LAST DAY. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN IMPRESSIVE CYCLONE, WITH A 12 NM WIDE EYE-FEATURE, SURROUNDED BY CONTINUOUS DEEP CONVECTION WRAPPING VERY TIGHTLY AROUND THE LOW-LEVEL CIRCULATION CENTER (LLCC). EIR IMAGERY HAS CONTINUED TO SHOW A VERY SYMMETRIC AND MODERATELY SIZED TC, WITH MINIMAL CONVECTIVE BANDS OUTSIDE OF THE TIGHTLY WRAPPED STRUCTURE. ON ANIMATED WATER VAPOR (WV) IMAGERY, STRONG RADIAL OUTFLOW ALOFT HAS BEEN OBSERVED OVER THE LAST 12 HOURS, CHARACTERIZED BY VISIBLE CIRRIFORM STRIATIONS BURSTING OUTWARD FROM THE IMMEDIATE CENTER. WITH REGARD TO THE ENVIRONMENT, VERTICAL WIND SHEAR (VWS) HAS REMAINED LOW (10-15 KTS) OVER THE PREVIOUS SIX HOURS, WHILE SEA SURFACE TEMPERATURES (SST) MAINTAIN A SUPPORTIVE 27-28 C. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE WELL-DEFINED AND OBSERVABLE EYE-FEATURE ON ANIMATED EIR IMAGERY. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON SUBJECTIVE AGENCY ESTIMATES RANGING BETWEEN 127 KTS AND 140 KTS, WHILE CIMSS OBJECTIVE ESTIMATES HAVE SHOWN A CEILING OF 136 KTS AT 120600Z.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: CURRENT INTENSITY EXCEEDS PREVIOUSLY EXPECTED INTENSITY BY 10 KTS. THERE ARE NO OTHER SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST. FORECAST DISCUSSION: TC 04S IS FORECASTED TO CONTINUE TRACKING GENERALLY WEST-SOUTHWESTWARD ALONG THE NORTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE LOCATED DIRECTLY TO THE SOUTH. BETWEEN TAU 24 AND TAU 36, CHIDO IS EXPECTED TO MOVE JUST NORTH OF THE NORTHERN MOST TIP OF MADAGASCAR. FOLLOWING TAU 36, THE TC WILL CONTINUE WEST-SOUTHWESTWARD, ALONG THE WESTWARD EXTENT OF THE AFOREMENTIONED RIDGE BUILDING INTO SOUTHERN MOZAMBIQUE. AFTER TAU 48, TC CHIDO WILL MOVE ANTICYCLONICALLY TOWARD THE SUBTROPICAL RIDGE AXIS, MAKING LANDFALL JUST AFTER TAU 72 AND NORTH OF NACALA, MOZAMBIQUE. BETWEEN TAU 72 AND TAU 96, TC 04S IS EXPECTED TO DISSIPATE AS THE SYSTEM MOVES INLAND. WITH REGARD TO INTENSITY, THE SYSTEM IS EXPECTED TO HAVE REACHED MAXIMUM INTENSITY OVER THE LAST FEW HOURS, WITH ITS INITIAL WEAKENING PHASE BEGINNING IMMINENTLY. WITH THAT BEING SAID, THE TC 04S IS FORECASTED TO ENCOUNTER AN INCREASE IN VWS INTO TAU 48 (20-25 KTS FROM THE EAST), ERODING THE SYSTEM TO 95 KTS DURING ITS WEST-SOUTHWESTWARD TRACK WEST OF NORTHERN MADAGASCAR. ALTHOUGH VWS WILL INITIALLY WEAKEN THE SYSTEM, TC CHIDO IS EXPECTED TO MAINTAIN A RELATIVELY HIGH INTENSITY OF 60 KTS JUST BEFORE MAKING LANDFALL AFTER TAU 72. AFTER LANDFALL, THE OVERALL INTENSITY WILL WEAKEN TO 30 KTS BY TAU 96 DUE TO INTERACTION WITH THE LOCAL TERRAIN.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN RELATIVELY GOOD AGREEMENT FOR THE TRACK OF TC 04S, WITH A CROSS-TRACK SPREAD OF 167 NM BY TAU 72. FOLLOWING TAU 72, TRACK SOLUTIONS BEGIN TO DIVERGE AFTER LANDFALL AND AROUND THE SUBTROPICAL RIDGE AXIS THROUGH DISSIPATION. THE JTWC FORECAST TRACK HAS REMAINED STEADY AND ALIGNED VERY CLOSELY WITH THE MULTI-MODEL CONSENSUS, LENDING HIGH TRACK CONFIDENCE OVER THE NEXT 72 HOURS. FOLLOWING LANDFALL, CONFIDENCE DECREASES DUE TO DISSIPATION OVER THE RUGGED TERRAIN OF MOZAMBIQUE. IN REGARD TO INTENSITY, THE MULTI-MODEL INTENSITY CONSENSUS IS IN AGREEMENT THAT STEADY WEAKENING IS EXPECTED FROM THE MOST RECENT ANALYSIS (120600Z) THROUGH THE END OF THE FORECAST PERIOD, WITH GFS INDICATING A MUCH QUICKER DROP-OFF IN SURFACE INTENSITIES AND BEING THE MOST SIGNIFICANT OUTLIER. OVERALL, THE JTWC INTENSITY FORECAST REMAINS CLOSE TO THE NUMERICAL MODEL INTENSITY CONSENSUS, LENDING MEDIUM CONFIDENCE TO THE INTENSITY FORECAST.

Platform: RCM-2 Acquisition Date: 2024-12-12 01:56:25 UTC Storm Name: SH042025 / CHIDO Storm ID: SH04 Storm Center Longitude: 55.198 Storm Center Latitude: -10.522 Incidence Angle (Degrees): 41.961 Quadrant 1 NE VMax (kts): 128.52 Quadrant 2 SE VMax (kts): 125.50 Quadrant 3 SW VMax (kts): 125.28 Quadrant 4 NW VMax (kts): 131.09 RMax (nmi): 9.00 - 9.00