WDPS31 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER)
WARNING NR 019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.8S 155.2E
   INITIAL INTENSITY: 70 KTS
   GEOGRAPHIC REFERENCE: 545 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS
TROPICAL CYCLONE (TC) 03P (JASPER) CONTINUING TO FIGHT AGAINST 
PROMINENT VERTICAL WIND SHEAR (VWS) AND MID-LEVEL DRY AIR ENTRAINMENT 
OVER THE PAST SIX HOURS. THE SYSTEMS MID TO UPPER-LEVEL VORTEX HAS
MANAGED TO WOBBLE BACK EQUATORWARD INTO BETTER VERTICAL ALIGNMENT
WITH THE LOW LEVEL CIRCULATION CENTER (LLCC), DESPITE THE
PERSISTING MODERATE TO HIGH (20 TO 25 KTS) VWS. A 091058Z ASCAT-C
SCATTEROMETRY IMAGE CAPTURED AN ASYMMETRIC WIND FIELD EXPANDING
MUCH FURTHER TO THE SOUTH THAN NORTH, ALTHOUGH THE SYMMETRY
HAS IMPROVED SINCE THE PREVIOUS WARNING (WRN 18). DEEP CONVECTION,
THOUGH STILL PRESENT UP TO 116NM OUTWARD FROM THE LLCC IN THE
WESTERN PERIPHERY, HAS WEAKENED AND RISING CLOUD TOP TEMPERATURES
ARE OBSERVED ON EIR SATELLITE IMAGERY. THE INITIAL POSITION IS 
ASSESSED WITH HIGH CONFIDENCE BASED ON A 091058Z ASCAT-C SCATTEROMETRY 
IMAGE. THE INITIAL INTENSITY OF 70 KNOTS IS ASSESSED WITH MEDIUM 
CONFIDENCE BASED ON THE AFOREMENTIONED ASCAT-C SCATTEROMETRY IMAGE AND 
THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   KNES: T4.5 - 77 KTS
   ABRF: T4.5 - 77 KTS
   CIMSS SATCON: 71 KTS AT 091250Z
   CIMSS ADT: 69 KTS AT 091130Z
   CIMSS AIDT: 71 KTS AT 091250Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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 03P (JASPER) CONTINUES EXPERIENCING VERTICAL 
WIND SHEAR AND NUMERICAL MODEL INDICATED MODERATE MID-LEVEL DRY AIR 
ENTRAINMENT. BOTH ARE EXPECTED TO CONTINUE INFLUENCING THE SYSTEM OVER 
THE NEXT 24 HOURS, TRANSPIRING A WEAKENING TREND TO OCCUR AS THE 
SYSTEM TRACKS WEST-SOUTHWESTWARD. AFTER TAU 24 AND ON A WESTWARD 
TRACK, VWS IS EXPECTED TO RAPIDLY DECREASE TO LOW (5-10 KTS) VALUES, 
ALLOWING THE TC A SUSTAINMENT WINDOW WITH DRY MID-LEVELS STILL A 
FACTOR. WARM (28-29 C) SEA SURFACE TEMPERATURES IN THE SHALLOW REEFS 
ALONG THE FORECASTED TRACK WILL ASSIST THE TC BY SUPPLYING NECESSARY 
HEAT TO THE SYSTEM. NEAR TAU 48, THE SYSTEM IS FORECAST TO TRACK WEST-
NORTHWESTWARD UNTIL TAU 72. MULTIPLE INDICATORS IN INTENSITY GUIDANCE 
SHOW TC 03P TO LIKELY UNDERGO A REMOISTENING OF THE CORE AND SLIGHT 
REINTENSIFICATION BETWEEN TAU 60 AND LANDFALL (NEAR TAU 84),
POTENTIALLY PEAKING AT 60-65KTS. A RAPID DECAY IS ANTICIPATED FROM
TAU 84 TO TAU 120 AS THE SYSTEM TRACKS WESTWARD ACROSS NORTHEASTERN
AUSTRALIA. OF NOTE, MULTIPLE GLOBAL MODELS TRANSIT THE VORTEX
ACROSS THE CAPE YORK PENINSULA THROUGH TAU 120 AND INTO THE GULF OF
CARPENTARIA OUTSIDE OF THE FORECAST WINDOW, WHERE REINTENSIFICATION
TO TC STRENGTH IS POSSIBLE.

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN GOOD
AGREEMENT ON BOTH TRACK AND INTENSITY. BY TAU 72, A CROSS-TRACK
SPREAD OF 95NM AND ALONG-TRACK SPREAD OF 94NM IS PRESENT AMONG THE
JTWC CONSENSUS MEMBERS, WHICH HAS GROWN IN UNCERTAINTY SINCE THE
PREVIOUS WARNING. WITH THE EXCEPTION OF STATISTICAL-DYNAMICAL
INTENSITY GUIDANCE, THE JTWC INTENSITY CONSENSUS MEMBERS SHOW A 15
KTS SPREAD BY TAU 72. THEREAFTER, CONSENSUS MEMBERS DIVERGE IN
SOLUTIONS A BIT FURTHER TO A CROSS-TRACK SPREAD OF 301NM AND ALONG-
TRACK SPREAD OF 214NM. HENCEFORTH, THE FORECAST CONFIDENCE FOR BOTH 
TRACK AND INTENSITY FROM TAU 00 TO TAU 120 IS MEDIUM.

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