WDPS31 PGTW 030900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09P (NINE) WARNING NR 
011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.0S 158.9E
   INITIAL INTENSITY: 20 KTS
   GEOGRAPHIC REFERENCE: 509 NM NORTHWEST OF NOUMEA, NEW CALEDONIA
   MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 8 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) A WEAK SYSTEM WITH
DISORGANIZED FLARING CONVECTION AND OBSCURED LOW LEVEL CIRCULATION
THAT IS PROPAGATING ALONG THE MONSOON TROUGH. THE INITIAL POSITION
AND INTENSITY ARE EXTRAPOLATED FROM A RECENT ASCAT PASS WITH MEDIUM
CONFIDENCE. ANALYSIS INDICATES A MARGINAL 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: 33 KTS AT 030540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   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
MARGINAL ENVIRONMENT WILL FUEL WEAK AND SLOW INTENSIFICATION TO
35KTS BY TAU 36 THEN TO A PEAK OF 40KTS AT TAUS 72-120 AS POLEWARD
OUTFLOW INCREASES. 

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH
THE FORECAST TRACK WITH UEMN, THE RIGHT OUTLIER, AND GFS, THE LEFT
OUTLIER, EXPANDING THE MODEL ENVELOPE SPREAD TO 670NM 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 BEYOND. 

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