Tropical Cyclone ERROL (29S)

WTXS31 PGTW 252100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04S (CHENGE) WARNING NR 020//
RMKS/
1. TROPICAL CYCLONE 04S (CHENGE) WARNING NR 020    
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   251800Z --- NEAR 8.1S 49.9E
     MOVEMENT PAST SIX HOURS - 260 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 020 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   REPEAT POSIT: 8.1S 49.9E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   260600Z --- 7.7S 48.2E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
    ---
REMARKS:
252100Z POSITION NEAR 8.0S 49.5E.
25OCT25. TROPICAL CYCLONE (TC) 04S (CHENGE), LOCATED APPROXIMATELY
635 NM EAST OF DAR ES SALAAM, TANZANIA, HAS TRACKED WESTWARD AT 06
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL IMAGERY
REVEALS A SHALLOW AND FULLY EXPOSED LOW-LEVEL CIRCULATION CENTER
AS DEEP CONVECTION HAS COMPLETELY COLLAPSED OVER THE LAST 12
HOURS. THE CURRENT ENVIRONMENT IS HIGHLY UNFAVORABLE WITH VERTICAL
WIND SHEAR ABOVE 30KTS AND STRAIGHT-LINE FLOW ALOFT. OVER THE NEXT
12 HOURS, THE REMNANTS OF TC 04S WILL CONTINUE TO DRIFT WEST-
NORTHWESTWARD AS THE SYSTEM CONTINUES TO WEAKEN IN AN ADVERSE
ENVIRONMENT. DETERMINISTIC MODEL GUIDANCE IS SUPPORTIVE OF THE
TRACK AND IS IN STRONG LINEAR AGREEMENT. THE INTENSITY GUIDANCE
VARIES SLIGHTLY BETWEEN STAGNATION AT 30KTS OVER THE NEXT 12 HOURS
OR CONTINUED WEAKENING. EITHER WAY, THE GUIDANCE DOES NOT INDICATE
RE-INTENSIFICATION. THIS IS THE FINAL WARNING ON THIS SYSTEM BY
THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE
CLOSELY MONITORED FOR SIGNS OF REGENERATION. MINIMUM CENTRAL
PRESSURE AT 251800Z IS 1003 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
251800Z IS 12 FEET.//
NNNN

WDXS31 PGTW 250900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04S (CHENGE) WARNING 
NR 019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 7.8S 51.5E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 706 NM NORTH-NORTHEAST OF ANTANANARIVO,
MADAGASCAR
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 04S (CHENGE) IS BEING HEAVILY SHEARED WITH
ASSOCIATED CONVECTION DISPLACED TO THE SOUTHWEST AS DEPICTED IN
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY. ENVIRONMENTAL
CONDITIONS REMAIN UNFAVORABLE WITH HIGH VERTICAL WIND SHEAR (25-30
KTS), SEA SURFACE TEMPERATURES OF 26 C TO 27 C, AND MODERATE
EQUATORWARD OUTFLOW. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON A 250612Z METOP-B ASCAT DATA AND A 250204Z
RCM-3 SAR PASS. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH
HIGH CONFIDENCE BASED ON THE AFOREMENTIONED ASCAT AND SAR PASSES.

INITIAL WIND RADII BASIS: 250204Z RCM-3 SAR DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   DEMS: T3.0 - 45 KTS
   CIMSS ADT: 49 KTS AT 250300Z
   CIMSS AIDT: 43 KTS AT 250500Z
   CIMSS D-MINT: 31 KTS AT 250200Z
   CIMSS D-PRINT: 30 KTS AT 250500Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 25-30 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: HIGH

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TS CHENGE WILL REMAIN ON A WEST-NORTHWESTWARD
TRACK FOR THE REMAINDER OF THE FORECAST PERIOD UNDER THE INFLUENCE
OF A SUBTROPICAL RIDGE TO THE SOUTH. LITTLE CHANGE IS EXPECTED IN
THE CIRCULATION TILL AFTER TAU 12 AT WHICH TIME PROLONGED EXPOSURE
TO HIGH WIND SHEAR WILL START TO WEAKEN TS CHENGE BELOW TROPICAL
STORM INTENSITY. BY TAU 36 TS CHENGE WILL HAVE FULLY DISSIPATED
OVER WATER.

MODEL DISCUSSION: CROSS TRACK SPREAD IS UNDER 45 NM FOR THE ENTIRE
FORECAST PERIOD SIGNIFYING GOOD CONSENSUS BETWEEN THE MODELS. THE
OFFICIAL JTWC TRACK IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS
WITH HIGH CONFIDENCE. THE INTENSITY SPREAD IS AROUND 10 KNOTS WITH
HAFS-A DROPPING THE STORM BELOW WARNING CRITERIA BEFORE THE REST OF
THE GUIDANCE. THE OFFICIAL JTWC INTENSITY FORECAST REFLECTS THE
MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
NNNN