WDPS31 PGTW 031500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09P (NINE) WARNING NR 
012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.6S 160.0E
   INITIAL INTENSITY: 20 KTS
   GEOGRAPHIC REFERENCE: 437 NM NORTHWEST OF NOUMEA, NEW CALEDONIA
   MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 8 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A WEAK
SYSTEM WITH DISORGANIZED FLARING CONVECTION AND OBSCURED LOW LEVEL
CIRCULATION
THAT IS PROPAGATING ALONG THE MONSOON TROUGH. THE INITIAL POSITION
IS PLACED WITH MEDIUM CONFIDENCE BASED ON A DEFINED, ALBEIT WEAK,
RAGGED, AND ELONGATED LOW LEVEL CIRCULATION FEATURE IN THE 031150Z
89GHZ GPM IMAGE. THE INITIAL INTENSITY IS PLACED WITH MEDIUM
CONFIDENCE BASED ON RECENT SMAP DATA AND CONSISTENT WITH THE
CONVECTIVE SIGNATURE. ANALYSIS INDICATES A MARGINALLY FAVORABLE
ENVIRONMENT WITH WARM (28-29C) SST AND MODERATE EASTWARD OUTFLOW
ALOFT OFFSET BY MODERATE VWS. THE CYCLONE IS TRACKING ALONG THE
SOUTHWEST PERIPHERY OF A LOW REFLECTION OF THE NER TO THE
NORTHEAST.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: LOW REFLECTION OF THE NEAR EQUATORIAL
RIDGE (NER) TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE
   CIMSS ADT: 35 KTS AT 030840Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE EASTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 09P WILL CONTINUE ON ITS CURRENT TRACK
UNDER THE NER. AFTER TAU 72, THE SUBTROPICAL RIDGE TO THE SOUTHEAST
WILL ASSUME STEERING AND DRIVE THE CYCLONE SOUTHWESTWARD. THE
MARGINALLY FAVORABLE ENVIRONMENT WILL FUEL WEAK AND SLOW
INTENSIFICATION TO A PEAK OF 50KTS BY TAU 96; AFTERWARD, INCREASING
VWS AND COOLING SST WILL REDUCE IT TO 45KTS BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH
THE FORECAST TRACK WITH AFUM ON THE RIGHT MARGIN AND GFS ON THE
LEFT, EXPANDING THE MODEL ENVELOPE SPREAD TO OVER 800NM AT
TAU 120. IN VIEW OF THIS, THERE IS MEDIUM CONFIDENCE IN THE JTWC
TRACK AND INTENSITY FORECASTS UP TO TAU 72 AND LOW CONFIDENCE
AFTERWARD. 


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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