WDPS32 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 19P (RAE) WARNING NR 
005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.1S 179.3W
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 144 NM EAST-SOUTHEAST OF SUVA, FIJI
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP
CONVECTION WRAPPING AROUND THE LOW-LEVEL CIRCULATION CENTER (LLCC),
CLEARLY ATTEMPTING TO DEVELOP AN EYE BUT NOT QUITE THERE. THE CENTER
IS CLEARING SLIGHTLY, PARTIALLY REVEALING THE LLCC. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 24-615Z F-17
SSMIS COLOR-ENHANCED 37GHZ IMAGE HIGHLIGHTING A MICROWAVE EYE
FEATURE WITH A DRY SLOT TO THE SOUTHWEST. THE INITIAL INTENSITY OF
65 KTS IS ASSESSED WITH HIGH CONFIDENCE MEDIUM CONFIDENCE BASED ON
THE OBJECTIVE CIMSS INTENSITY DATA LISTED BELOW, LENDING HIGHER
INTENSITY VALUES THAN THE AGENCY FIXES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: WEAKLY STEERED BY AN EXTENSION OF A
NEAR EQUATORIAL RIDGE (NER) TO THE EAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   PHFO: T4.0 - 65 KTS
   NFFN: T3.5 - 55 KTS
   CIMSS SATCON: 66 KTS AT 240147Z
   CIMSS ADT: 74 KTS AT 240530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THE RATE OF INTENSIFICATION IS SLOWER
WITH A LOWER PEAK INTENSITY DUE TO MODERATE SHEAR THAT WILL
INCREASE AS THE TROPICAL CYCLONE APPROACHES THE SUBTROPICAL JET TO
THE SOUTH.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 19P WILL TRACK SLOWLY TO
THE SOUTH OVER THE NEXT 12 HOURS BEFORE CURVING SOUTHEASTWARD AS
THE SYSTEM ROUNDS THE WESTERN PERIPHERY OF THE NER. THE SYSTEM WILL
INTENSIFY SLIGHTLY TO A PEAK OF 70KTS OVER THE NEXT 12 HOURS WHILE
IN A FAVORABLE ENVIRONMENT WITH MODERATE VERTICAL WIND SHEAR, WARM
SEA SURFACE TEMPERATURES, AND A STRONG POLEWARD OUTFLOW CHANNEL.
HOWEVER, AS THE SYSTEM TRACKS POLEWARD TOWARDS THE SUBTROPICAL JET
TO THE SOUTH, VERTICAL WIND SHEAR WILL INCREASE AND INJECT DRY AIR
INTO THE VORTEX. THE SYSTEM WILL MOVE INTO AN AREA OF COOLER WATER
AT TAU 36 WHICH WILL INITIATE SUBTROPICAL TRANSITION IN TANDEM WITH
THE JET INFLUENCE. BY TAU 48, SUBTROPICAL TRANSITION WILL BE
COMPLETE.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN STRONG
AGREEMENT THAT THE SYSTEM WILL CURVE SOUTHEASTWARD THROUGHOUT THE
FORECAST PERIOD. THE CROSS-TRACK SPREAD OF THE JTWC MULTI-MODEL
CONSENSUS IS 65NM BY TAU 48. THE INTENSITY GUIDANCE DROPPED
SIGNIFICANTLY SINCE THE LAST INITIALIZATION, BUT REMAINS IN GOOD
AGREEMENT THAT A PEAK INTENSITY WILL OCCUR WITHIN THE NEXT 12-24
HOURS.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   INTENSITY 0 - 72 HR: HIGH//
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