WDPS31 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER)     
WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.5S 156.5E
   INITIAL INTENSITY: 115 KTS
   GEOGRAPHIC REFERENCE: 634 NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 03 KTS
   SIGNIFICANT WAVE HEIGHT: 38 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE (TC) 03P PEAKED AT ABOUT 120-125 KNOTS NEAR 080000Z 
AFTER FORMING A SYMMETRIC, CLEAR EYE. SINCE THAT TIME, ANIMATED 
MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES A STEADY WEAKENING 
TREND WITH A CLOUD-FILLED EYE AND ERODING DEEP CONVECTION OVER THE 
WESTERN SEMICIRCLE DUE TO DRY AIR ENTRAINMENT AND CONVERGENT UPPER-
LEVEL FLOW. A 080705Z SSMIS 91 GHZ COLOR COMPOSITE MICROWAVE IMAGE 
DEPICTS A 30 NM DIAMETER MICROWAVE EYE FEATURE, WITH A BREAK IN THE 
EYEWALL OVER THE NORTHERN QUADRANT AND EXPOSED SHALLOW BANDING OVER 
THE NORTHERN SEMICIRCLE. MICROWAVE IMAGERY INDICATES THAT THE BULK OF 
THE DEEP CONVECTIVE BANDING IS LOCATED OVER THE SOUTHERN SEMICIRCLE. 
BASED ON A 080512Z SSMIS 91 GHZ MICROWAVE IMAGE AND THE 
AFOREMENTIONED 080705Z SSMIS 91 GHZ IMAGE, THERE IS HIGH CONFIDENCE 
IN THE INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED AT 115 
KNOTS BASED ON THE SUBJECTIVE DVORAK INTENSITY ESTIMATES AS WELL AS 
THE CIMSS OBJECTIVE INTENSITY ESTIMATES RANGING FROM 110 TO 122 
KNOTS. 

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WEAK EXTENSION OF THE SUBTROPICAL RIDGE
(STR) TO THE EAST WITH A STRONG STR ENTRENCHED TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   KNES: T6.0 - 115 KTS
   ABRF: T6.0 - 115 KTS
   CIMSS SATCON: 110 KTS AT 080530Z
   CIMSS ADT: 122 KTS AT 080600Z
   CIMSS AIDT: 112 KTS AT 080600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: TC 03P IS FORECASTED TO GRADUALLY TURN
SOUTHWESTWARD TO WEST-SOUTHWESTWARD THROUGH TAU 48 AS IT
TRANSITIONS TO THE STEERING INFLUENCE OF THE STR POSITIONED TO THE
SOUTH. STEADY WEAKENING WILL OCCUR DUE TO STRONG DRY AIR ENTRAINMENT
AND INCREASING (20 TO 30 KNOTS) VERTICAL WIND SHEAR (VWS) ASSOCIATED 
WITH AN UPPER-LEVEL TROUGH IMPINGING ON THE WESTERN PERIPHERY OF THE 
SYSTEM. AFTER TAU 48, TC 03P WILL TRACK WESTWARD ALONG THE NORTHERN 
PERIPHERY OF THE STR TO THE SOUTH, WHICH IS EXPECTED TO MAINTAIN 
THROUGH TAU 120. ADDITIONAL WEAKENING WILL OCCUR THROUGH TAU 72, 
HOWEVER, REINTENSIFICATION IS ANTICIPATED IN THE LATER TAUS AS VWS 
RELAXES AND THE SYSTEM GOES THROUGH A RE-MOISTENING PHASE.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN IMPROVED AGREEMENT, 
ESPECIALLY THROUGH TAU 72, WITH A CROSS-TRACK SPREAD OF ONLY 77 NM AT 
TAU 72. AFTER TAU 72, GUIDANCE DIVERGES WITH A 228 NM CROSS-TRACK 
SPREAD AT TAU 120. THE 080000Z ECMWF AND GFS ENSEMBLES ALSO REVEAL 
INCREASING UNCERTAINTY AFTER TAU 72. RELIABLE INTENSITY GUIDANCE 
SUPPORTS THE JTWC FORECAST PHILOSOPHY WITH ALL MESOSCALE MODELS 
SHOWING A REINTENSIFICATION PHASE AFTER TAU 72. ADDITIONALLY, THE 
080000Z COAMPS-TC ENSEMBLE INDICATES A 40 TO 50 PERCENT PROBABILITY 
OF MODERATE INTENSIFICATION AFTER TAU 72.     

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