WDPS31 PGTW 100900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER)
WARNING NR 022//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.1S 154.0E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 474 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 28 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
CYCLONE (TC) 03P (JASPER) EXPERIENCING THE EFFECT OF SIGNIFICANT
NORTHWESTERLY SHEARING, SHOWING A POLEWARD TILTING VERTICAL
STRUCTURE. COMPARISON OF A 100254Z ATMS 165GHZ MICROWAVE IMAGE AND
A 100252Z AMSR2 36GHZ MICROWAVE IMAGE YIELDS 63NM HORIZONTALLY
BETWEEN THE CENTER OF ROTATION IN THE LOWER AND UPPER LEVELS. DEEP
FLARING CONVECTION PERSISTS BUT IS CONFINED MOSTLY TO THE WESTERN
PERIPHERY OF THE SYSTEM. SURFACE OBSERVATIONS (LIHOU REEF
LIGHTHOUSE) 156NM WEST-SOUTHWEST OF THE LOW-LEVEL CIRCULATION
CENTER (LLCC) REPORTED 43KTS SUSTAINED AT 100800Z. THE INITIAL
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON EXTRAPOLATION OF
THE AFOREMENTIONED AMSR2 MICROWAVE IMAGE AND ANIMATED HIMAWARI-9
VISIBLE SATELLITE IMAGERY. THE INITIAL INTENSITY OF 55 KTS IS
ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE SUBJECTIVE AND
OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: NORTHERN PERIPHERY OF A DEEP-LAYER
SUBTROPICAL RIDGE (STR) CENTERED NORTHEAST OF SYDNEY.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   KNES: T4.0 - 65 KTS
   ABRF: T4.0 - 65 KTS
   CIMSS SATCON: 50 KTS AT 100600Z
   CIMSS ADT: 51 KTS AT 100600Z
   CIMSS DPRINT: 51 KTS AT 100600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE 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: WITH TC 03P (JASPER) CONTINUING TO BE IMPACTED
BY MODERATE TO HIGH (20-25KTS) VERTICAL WIND SHEAR (VWS) THROUGH
TAU 18, A GRADUAL WEAKENING AND DROP IN INTENSITY IS ANTICIPATED
WHILE THE SYSTEM TRACKS WEST-SOUTHWESTWARD. THEREAFTER, HOWEVER, VWS 
DROPS SIGNIFICANTLY TO 5-10 KTS FOR THE REMAINDER OF THE FORECAST 
PERIOD. ADDITIONALLY, AS THE SYSTEM TRACKS WEST-NORTHWESTWARD 
BEGINNING NEAR TAU 24, SEA SURFACE TEMPERATURE (27-28 C) WILL REMAIN 
CONDUCIVE FOR SLIGHT INTENSIFICATION TO OCCUR AND RELATIVE HUMIDITY IS 
EXPECTED TO SLIGHTLY IMPROVE, INCREASING TO NEAR 70 PERCENT BY TAU 72. 
A RAPID WEAKENING PHASE IS ANTICIPATED TO OCCUR AS THE VORTEX TRANSITS 
WESTWARD ACROSS THE CAPE YORK PENINSULA AND INTO THE GULF OF
CARPENTARIA TO DISSIPATION (TAU 120).

MODEL DISCUSSION: GLOBAL NUMERICAL MODELS ARE IN EXCEPTIONAL
AGREEMENT IN TERMS OF TRACK SPEED AND GENERAL TRACK PATTERN OF TC 03P. 
ALL CONSENSUS MEMBERS, AS WELL AS HAFS-A AND HWRF, SHOW GENERAL
WEST-SOUTHWESTWARD MOTION THROUGH TAU 24 AND THEN EXHIBIT A GRADUAL 
TURN TO A WEST-NORTHWESTWARD TRACK.  DURING THE TAU 00 TO TAU 24
INTERVAL, ALL BUT ONE MEMBER OF THE JTWC INTENSITY CONSENSUS SLIGHTLY 
DOWNTRENDS INTENSITY OF THE TC. FROM TAU 24 TO TAU 60, AND ON
WEST-NORTHWESTWARD TRACK, INTENSITY GUIDANCE SUGGESTS A GRADUAL
REINTENSIFICATION OF 5-10KTS. CONTINUING ON A WESTWARD TRACK FROM
TAU 60, INTENSITY GUIDANCE SUGGESTS A RAPID DECLINE IN INTENSITY
BEGINNING NEAR TAU 72 AS THE SYSTEM NEARS LANDFALL (TAU 78 TO TAU
84). THE MOST PERTINENT UNCERTAINTY IN NUMERICAL MODEL GUIDANCE IS 
PRESENTED IN THE 72 HOUR CROSS-TRACK SPREAD, MEASURING 143NM BETWEEN 
THE GALWEM AND ECMWF SOLUTIONS.

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