WDPS31 PGTW 231500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 07P (SEVEN)      
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.3S 153.5E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 442 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
A BROAD UPPER-LEVEL LOW REMAINS ENTRENCHED OVER THE SYSTEM, HINDERING 
CORE CONVECTIVE DEVELOPMENT, WITH GOOD POLEWARD VENTING INTO A JET TO 
THE SOUTHEAST HELPING SUSTAIN DEEP CONVECTION OVER THE SOUTHERN 
SEMICIRCLE. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY REVEALS A 
BROAD, EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH FRAGMENTED DEEP 
CONVECTIVE BANDING OVER THE EASTERN QUADRANT AND SOUTHERN SEMICIRCLE. 
A 231110Z MHS 89 GHZ MICROWAVE IMAGE REVEALS A RELATIVELY UNIMPRESSIVE 
CONVECTIVE STRUCTURE WITH SHALLOW BANDING WRAPPING AROUND A BROAD LLC. 
A 231012Z SCATTEROMETER PASS ALSO INDICATES A BROAD WEAK CORE WITH 
PATCHY GALE-FORCE WINDS DISPLACED OVER THE NORTHERN AND SOUTHERN 
QUADRANTS. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED 
ON THE RECENT SCATTEROMETER PASS. THE INITIAL INTENSITY REMAINS 
ASSESSED AT 35 KTS WITH MEDIUM CONFIDENCE BASED ON SUBJECTIVE DVORAK 
ESTIMATES FROM PGTW AND ABRF, RECENT SCATTEROMETER DATA AND THE RECENT 
CIMSS ADT ESTIMATE. 

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: BUILDING SUBTROPICAL RIDGE (STR) 
POSITIONED TO THE SOUTH AND SOUTHWEST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   ABRF: T2.5 - 35 KTS
   CIMSS ADT: 33 KTS AT 231130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 07P IS TRACKING SLOWLY ALONG AN EXTENSION OF 
THE STR TO THE SOUTH AND IS FORECASTED TO TURN WESTWARD TO WEST-
SOUTHWESTWARD AFTER TAU 12 AS THE STR TO THE SOUTH BECOMES THE 
DOMINANT STEERING INFLUENCE THROUGH THE FORECAST PERIOD. OVER THE NEXT 
DAY, THE UPPER-LEVEL LOW IS EXPECTED TO GRADUALLY ERODE, REPLACED BY
UPPER-LEVEL RIDGING. THIS WILL ALLOW THE SYSTEM TO INTENSIFY AT A
FASTER RATE TO A PEAK INTENSITY OF 55 KNOTS AT LANDFALL NEAR TAU 48. 
AFTER TAU 48, THE SYSTEM WILL RAPIDLY WEAKEN AS IT TRACKS INLAND, WITH 
DISSIPATION ANTICIPATED BY TAU 72.       

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT WITH A CROSS-TRACK SPREAD OF ONLY 57 NM AT TAU 48. HOWEVER, 
SIGNIFICANT UNCERTAINTY IN THE INITIAL POSITION WILL CONTINUE THROUGH 
TAU 24 THUS OVERALL CONFIDENCE IN THE JTWC TRACK FORECAST IS MEDIUM. 
DUE TO THE COMPLEX, EVOLVING UPPER-LEVEL ENVIRONMENT, THERE IS MEDIUM 
CONFIDENCE IN THE JTWC INTENSITY FORECAST. RELIABLE INTENSITY 
GUIDANCE, INCLUDING THE HAFS-A AND COAMPS-TC FORECASTS, INDICATES A 
PEAK INTENSITY RANGING FROM 50 TO 60 KNOTS. THE 221800Z COAMPS-TC 
ENSEMBLE INTENSITY PROBABILITIES SHOW LOW PROBABILITY (20 TO 30 
PERCENT) OF MODERATE INTENSIFICATION OVER THE NEXT TWO DAYS.   

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