WDPS32 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09P (NINE) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.1S 154.8E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 530 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: EASTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES AN EXPOSED, WEAK
LOW-LEVEL CIRCULATION (LLC) WITH FLARING DEEP CONVECTION ON THE
NORTHWESTERN PERIPHERY. A 020624Z SSMIS 91GHZ MICROWAVE IMAGE
REVEALED A RAGGED AND WEAKLY DEFINED LLC WITH A BURST OF DEEP
CONVECTION TO THE NORTHWEST. TC 09P IS LOCATED UNDER AN UPPER-LEVEL
COL REGION WITH COMPLEX FLOW; DEEP CONVECTION IS FLARING UNDER THE
DIVERGENT REGION OF THE COL WHILE THE LLC IS LOCATED UNDER THE
CONVERGENT REGION. POLEWARD OUTFLOW IS RESTRICTED DUE TO THE
PRESENCE OF AN UPPER-LEVEL LOW AND TROUGH TO THE SOUTH AND
SOUTHEAST. ADDITIONALLY, THERE IS SIGNIFICANT DRY AIR PRESENT OVER
THE SOUTHERN PERIPHERY OF THE SYSTEM WITH MID-LEVEL DRY AIR
ENTRAINMENT. SEA SURFACE TEMPERATURES (29-30C) AND VERTICAL WIND
SHEAR REMAIN CONDUCIVE. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE MSI. THE INITIAL INTENSITY OF 30 KTS IS
ASSESSED WITH HIGH CONFIDENCE BASED ON A BLEND OF DVORAK ESTIMATES
AND THE CIMSS ADT ESTIMATE.

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

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) POSITIONED
TO THE NORTH AND NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   KNES: T1.0 - 25 KTS
   CIMSS SATCON: 39 KTS AT 020316Z
   CIMSS ADT: 37 KTS AT 020540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: WEAK EQUATORWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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 IS FORECAST TO TRACK EASTWARD TO
EAST-SOUTHEASTWARD UNDER THE STEERING INFLUENCE OF THE NER THROUGH
TAU 72. TC 09P WILL MAINTAIN INTENSITY AT 30 KNOTS THROUGH TAU 24
DUE TO DRY AIR ENTRAINMENT AS WELL WEAK OUTFLOW ALOFT. AFTER TAU 24, 
THE SYSTEM WILL INTENSIFY SLOWLY AS POLEWARD OUTFLOW IMPROVES AND 
THE CORE ENVIRONMENT MOISTENS. AFTER TAU 72, TC 09P WILL GRADUALLY 
TURN SOUTHEASTWARD ALONG THE WESTERN FLANK OF A BUILDING SUBTROPICAL 
RIDGE (STR) TO THE EAST. THE SYSTEM WILL PEAK AT 55 KNOTS BY TAU 96 
THEN WEAKEN SLIGHTLY, HOWEVER, THIS PORTION OF THE INTENSITY FORECAST
IS UNCERTAIN DUE TO POSSIBLE DRY AIR ENTRAINMENT AND SLIGHTLY COOLER
SEA SURFACE TEMPERATURES (27-28C).  

MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT WITH A
230NM SPREAD IN SOLUTIONS AT TAU 72 AND REMAIN IN FAIR AGREEMENT
THROUGH TAU 120. THE 020000Z ECMWF ENSEMBLE (EPS) STRIKE
PROBABILITY GRAPHIC SUPPORTS THE JTWC FORECAST TRACK WITH MEDIUM
CONFIDENCE. THE BULK OF THE DETERMINISTIC AND ENSEMBLE GUIDANCE 
TURNS THE SYSTEM SOUTHEASTWARD BETWEEN NEW CALEDONIA AND VANUATU. 
RELIABLE INTENSITY GUIDANCE SUPPORTS THE JTWC INTENSITY FORECAST 
WITH HWRF INDICATING A PEAK OF NEAR 50 KTS NEAR TAU 96 AND THE JTWC 
INTENSITY CONSENSUS (ICNW) SHOWING A PEAK OF 60 KTS NEAR TAU 96. 

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