WDPS31 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER)     
WARNING NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 13.1S 156.7E
   INITIAL INTENSITY: 95 KTS
   GEOGRAPHIC REFERENCE: 671 NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 36 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A WEAK,
FORMATIVE EYE WITH DEEP CONVECTION CYCLING RAPIDLY. A 071136Z MHS
89 GHZ MICROWAVE IMAGE SHOWS A SYMMETRIC EYEWALL SURROUNDING A
MICROWAVE EYE FEATURE WITH SPIRAL BANDING CONFINED PRIMARILY TO THE
SOUTHERN SEMICIRCLE. POLEWARD OUTFLOW REMAINS ROBUST, ENHANCED BY
THE SUBTROPICAL JET POSITIONED TO THE SOUTH. THE INITIAL POSITION
IS PLACED WITH HIGH CONFIDENCE BASED ON A 071140Z ASCAT-C BULLSEYE
IMAGE AS WELL AS EIR IMAGERY. THE 34-KNOT AND 50-KNOT WIND RADII
ARE BASED ON A DETAILED ANALYSIS OF THE RECENT ASCAT DATA. THE
INITIAL INTENSITY OF 95 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES RANGING FROM 90
TO 102 KNOTS. THIS IS CONSISTENT WITH A 070807Z RCM-1 SAR IMAGE
INDICATING MAXIMUM WINDS OF 87 KNOTS.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: WEAK SUBTROPICAL RIDGE (STR) POSITIONED
TO THE EAST WITH A STRONGER STR ENTRENCHED TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   KNES: T5.0 - 90 KTS
   CIMSS ADT: 115 KTS AT 071130Z
   CIMSS AIDT: 95 KTS AT 071130Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 03P IS FORECAST TO INTENSIFY THROUGH TAU 12
TO A PEAK INTENSITY OF 105 KNOTS WITH A SLOW SOUTH-SOUTHWESTWARD
TRACK ALONG THE WESTERN PERIPHERY OF A WEAK EASTERN STR. A HIGHER 
PEAK INTENSITY IS POSSIBLE WIHIN THE NEXT 24 HOURS DUE TO THE 
FAVORABLE ENVIRONMENTAL CONDITIONS. AFTER TAU 24, TC 03P WILL TRACK 
SOUTHWESTWARD TO WESTWARD AS THE STEERING INFLUENCE TRANSITIONS TO 
THE MORE DOMINANT STR TO THE SOUTH. AFTER TAU 24, ENVIRONMENTAL 
CONDITIONS ARE EXPECTED TO DEGRADE AS THE SYSTEM INTERACTS WITH AN 
APPROACHING UPPER-LEVEL SHORT-WAVE TROUGH WITH INCREASING VERTICAL 
WIND SHEAR (VWS) OF 20-30 KNOTS FROM TAU 18 TO TAU 72. THE 070600Z 
HAFS-A RUN ALSO INDICATES SIGNIFICANT DRY AIR ASSOCIATED WITH THE 
TROUGH WILL ENTRAIN INTO THE NORTHERN REGION OF THE SYSTEM, WHICH 
WILL SERVE TO STEADILY WEAKEN THE SYSTEM THROUGH TAU 96. AFTER TAU 
96, HAFS-A INDICATES A GRADUAL RE-MOISTENING OF THE CORE, WHICH, 
ALONG WITH DECREASING VWS, WILL ALLOW THE SYSTEM TO REINTENSIFY 
SLIGHTLY BY TAU 120.   

MODEL DISCUSSION: WITH THE EXCEPTION OF THE GALWEM AND UK-MET 
ENSEMBLE MEAN TRACKERS, WHICH REMAIN SLOW AND ON THE NORTHERN EDGE OF 
THE AIDS ENVELOPE, THE BULK OF THE NUMERICAL MODEL GUIDANCE REMAINS 
IN FAIR AGREEMENT SUPPORTING THE JTWC FORECAST TRACK WITH MEDIUM 
CONFIDENCE. GFS HAS SHIFTED NORTH AND IS NOW IN CLOSE AGREEMENT WITH 
THE ECMWF AND ECMWF ENSEMBLE MEAN TRACKERS. CONSEQUENTLY, CROSS-TRACK 
SPREAD HAS DECREASED WITH HIGHER CONFIDENCE IN A TRACK TOWARD OR VERY 
CLOSE TO WILLIS ISLAND. ALTHOUGH A WEAK EYE HAS FORMED WITH 
INCREASING POTENTIAL FOR MODEST INTENSIFICATION, THE 070600Z COAMPS-
TC ENSEMBLE SHOWS ZERO PROBABILITY OF RAPID INTENSIFICATION (RI) 
THROUGH TAU 72 AND NONE OF THE RI AIDS ARE TRIGGERING AT THIS TIME. 
HOWEVER, RI PROBABILITIES HAVE INCREASED TO 10 PERCENT AFTER TAU 72 
SUPPORTING THE REINTENSIFICATION PHASE.          

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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