WDXS32 PGTW 192100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 06S (ANGGREK)
WARNING NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.7S 92.4E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 263 NM WEST OF COCOS ISLANDS
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 21 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
CYCLONE (TC) 06S (ANGGREK) SLOWLY TRACKING WEST-SOUTHWESTWARD AT 3
KNOTS OVER THE PAST 12 HOURS. WARMING CLOUD TOP TEMPERATURES OF
CENTRALIZED CONVECTION AND A GENERAL DECREASE IN HORIZONTAL EXTENT
OF THE CIRRUS CANOPY ARE INDICATIVE OF DECREASED CONVECTION AND
MARK THE BEGINNING OF A GRADUAL WEAKENING TREND. FAVORABLE VERTICAL
WIND SHEAR (VWS) IS ANTICIPATED TO REMAIN LOW (10-15KTS) THROUGHOUT
THE FORECAST INTERVAL, WITH CONDUCIVE SEA SURFACE TEMPERATURE
(27-28 C). HOWEVER, DRY AIR MASSES TO THE WEST AND SOUTHEAST OF
THE LLCC HAVE BEGUN TO ENTRAIN THE SYSTEM AND ARE ANTICIPATED TO
TRANSPIRE INTO THE AFOREMENTIONED WEAKENING PHASE. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON 191514Z METOP-C
SCATTEROMETRY IMAGE AND A 191800Z CIRA PROXYVIS SATELLITE IMAGE.
THE INITIAL INTENSITY OF 55 KTS IS ASSESSED WITH HIGH CONFIDENCE
BASED ON THE AFOREMENTIONED SCATTEROMETRY IMAGE, AS WELL AS THE
SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) POSITIONED TO
THE SOUTHWEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   APRF: T3.0 - 45 KTS
   CIMSS SATCON: 51 KTS AT 191800Z
   CIMSS ADT: 53 KTS AT 191800Z
   CIMSS DPRINT: 57 KTS AT 191800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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: TC 06S (ANGGREK) IS FORECAST TO TRACK
WEST-NORTHWEST TO NORTHWESTWARD THROUGH TAU 60 AS IT EXPERIENCES
THE STEERING INFLUENCE OF A STR SOUTHWEST OF THE LLCC. DURING THIS
TIME, DRY AIR ENTRAINMENT IS ANTICIPATED TO GRADUALLY IMPACT THE
SYSTEM. BETWEEN TAU 60 AND TAU 72, THE TC IS FORECAST TO TURN ONTO
A NEAR RECIPROCAL HEADING DUE TO THE EXTENSION OF THE AFOREMENTIONED
STR. SLOW TRACK SPEEDS (1-3 KTS) MAY CAUSE UPWELLING OF COOLER SEA
WATER (26C AND LOWER) TO INTERACT WITH THE SYSTEM, FURTHERING THE
FORECAST INTENSITY DOWNTREND.

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN FAIR
AGREEMENT UP TO TAU 60, WITH MOST MEMBERS OF THE JTWC CONSENSUS
PRESENTING A SLOW NORTHWESTWARD TRACK.  INTENSITY GUIDANCE SUGGESTS
A GRADUAL DECAY HAS BEGUN AND WILL CONTINUE THROUGH AT LEAST TAU 60
TO NEAR 45KTS. AFTER TAU 60, HOWEVER, THERE IS HIGH DISAGREEMENT
AMONG CONSENSUS MEMBERS.  ALL MEMBERS, WITH THE EXCEPTION OF
NAVGEM, STEER THE SYSTEM OFF OF THE NORTHWESTWARD TRACK AND SHARPLY
TURN SYSTEM BETWEEN TAU 60 AND TAU 72. THE TIMING AND DIRECTION OF
TURN VARIES GREATLY THROUGHOUT MODEL SOLUTIONS PRESENTED, LEADING TO 
A FORECAST CONFIDENCE OF LOW AFTER TAU 72.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: MEDIUM
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: LOW//
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