WDPS31 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 01P (ONE)        
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 10.1S 167.6E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 458 NM NORTH OF PORT VILA, VANUATU
   MOVEMENT PAST 6 HOURS: SOUTHWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
CONSOLIDATING LOW-LEVEL CIRCULATION, WITH INTENSE CONVECTIVE BURSTS
FLARING WITHIN A CYCLONICALLY ROTATING CORE AND EXTENSIVE DEEP
CONVECTIVE BANDING OVER THE SOUTHERN SEMICIRCLE. DUE TO THE LACK OF
MICROWAVE IMAGERY AND ASCAT IMAGERY, THERE IS MEDIUM CONFIDENCE IN
THE INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED AT 40 KNOTS
BASED ON THE DVORAK SUBJECTIVE INTENSITY ESTIMATES AND THE RECENT 
CIMSS ADT ESTIMATE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: NORTH-SOUTH ORIENTED NEAR-EQUATORIAL
RIDGE (NER) POSITIONED TO THE EAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   KNES: T3.0 - 45 KTS
   PHFO: T3.0 - 45 KTS
   CIMSS ADT: 39 KTS AT 212340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 01P IS FORECAST TO TRACK
SLOWLY SOUTHWARD TO SOUTH-SOUTHWESTWARD ALONG THE WESTERN PERIPHERY
OF THE NER THROUGH TAU 48. DUE TO HIGHLY FAVORABLE ENVIRONMENTAL
CONDITIONS INCLUDING ENHANCED POLEWARD OUTFLOW, LOW VERTICAL WIND
SHEAR (VWS) AND WARM SST, TC 01P IS FORECAST TO RAPIDLY INTENSIFY
THROUGH TAU 48 TO A PEAK INTENSITY OF 100 KNOTS. AFTER TAU 48, TC
01P WILL TURN SOUTHWESTWARD AS AN EXTENSION OF THE SUBTROPICAL
RIDGE (STR) BUILDS TO THE SOUTH IN RESPONSE TO AN APPROACHING
SUBTROPICAL SHORTWAVE TROUGH. AFTER TAU 72, THE SYSTEM WILL BEGIN
TO ACCELERATE SOUTHWARD AS IT ENCOUNTERS WEAK SUBTROPICAL WESTERLY
FLOW. STEADY WEAKENING SHOULD OCCUR AFTER 60 AS ENVIRONMENTAL
CONDITIONS DEGRADE WITH INCREASING VWS AND COOLER SST (26-25 C).   

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT
THROUGH TAU 36 WITH INCREASING UNCERTAINTY (LOW CONFIDENCE) AFTER
TAU 36. CROSS-TRACK SPREAD JUMPS FROM 330 NM AT TAU 72 TO 760 NM AT
TAU 120. THIS LARGE SPREAD IS ALSO REFLECTED IN THE 211800Z GEFS
AND 211200Z EPS ENSEMBLE GUIDANCE ALTHOUGH THE BULK OF THE
SOLUTIONS INDICATE A TRACK TOWARD NEW CALEDONIA. OVERALL, TRACK
CONFIDENCE IS LOW THROUGH TAU 120. RELIABLE INTENSITY GUIDANCE IS
IN FAIR AGREEMENT WITH THE MESOSCALE MODELS (HAFS-A, COAMPS-TC (GFS
AND NAVGEM VERSIONS)) SHOWING PEAK INTENSITIES IN THE 95-102 KNOT
RANGE NEAR TAU 48. THE 211200Z COAMPS-TC ENSEMBLE (GFS VERSION)
INDICATES HIGH PROBABILITY VALUES OF 60 TO 90 PERCENT FROM TAU 6 TO
TAU 40. ADDITIONALLY, RAPID INTENSIFICATION (RI) GUIDANCE HAS
TRIGGERED SUPPORTING THE RI PHASE THROUGH TAU 48.   

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