WDPS31 PGTW 090900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER)
WARNING NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.0S 155.5E
   INITIAL INTENSITY: 80 KTS
   GEOGRAPHIC REFERENCE: 561 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 07 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
CYCLONE (TC) 03P (JASPER) STRUGGLING TO MAINTAIN INTENSITY IN A
MARGINALLY UNFAVORABLE ENVIRONMENT OVER THE PAST SIX HOURS.  THE
SYSTEMS VORTEX HAS BECOME TILTED POLEWARD WITH HEIGHT, MOSTLY DUE
TO THE MODERATE TO HIGH (20-25 KTS) VERTICAL WIND SHEAR (VWS). A
090346Z AMSR2 SATELLITE WIND SPEED IMAGE SHOWS THE VWS TO BE GREATLY
AFFECTING WIND FIELD SYMMETRY AS WELL, DISPLACING NEARLY ALL WIND 
SPEED VALUES GREATER THAN 50KTS TO THE SOUTHEASTERN QUADRANT OF THE 
SYSTEM. THE MOSTLY OBSCURED LOW-LEVEL CIRCULATION CENTER (LLCC) HAS
STARTED TO EMERGE FROM THE SHEARED MID AND UPPER LEVELS ALONG THE
WESTERN PERIPHERY OF THE SYSTEM. DESPITE THE OFFSET AND TILT OF THE
VORTEX, DEEP FLARING CONVECTION PERSISTS, WITH OVERSHOOTING CLOUD
TOPS IN THE SOUTHERN PERIPHERY. THE INITIAL POSITION IS ASSESSED WITH 
LOW CONFIDENCE BASED ON ANIMATED HIMAWARI-9 VISIBLE SATELLITE IMAGERY. 
THE INITIAL INTENSITY OF 80 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE 
BASED ON THE SUBJECTIVE AND OBJECTIVE INTENSITY GUIDANCE LISTED BELOW.

INITIAL WIND RADII BASIS: OTHER 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   ABRF: T4.5 - 77 KTS
   CIMSS SATCON: 69 KTS AT 090600Z
   CIMSS ADT: 82 KTS AT 090600Z
   CIMSS AIDT: 71 KTS AT 090600Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   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 (JASPER) HAS BEGUN EXPERIENCING
SUBSTANTIAL VERTICAL WIND SHEAR AND 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 
SHOW TC 03P TO LIKELY UNDERGO A REMOISTENING OF THE CORE AND SLIGHT 
REINTENSIFICATION BETWEEN TAU 66 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 EXCEPTIONAL
AGREEMENT ON BOTH TRACK AND INTENSITY. BY TAU 72, A TIGHT
CROSS-TRACK SPREAD OF 68NM AND ALONG-TRACK SPREAD OF 69NM IS
PRESENT AMONG THE JTWC CONSENSUS MEMBERS. WITH THE EXCEPTION OF
STATISTICAL-DYNAMICAL INTENSITY GUIDANCE, THE JTWC INTENSITY
CONSENSUS MEMBERS SHOW JUST A 10 KTS SPREAD OVER THE SAME INTERVAL.
THUS, THE FORECAST CONFIDENCE OF BOTH TRACK AND INTENSITY IS HIGH
THROUGH TAU 72. THEREAFTER, CONSENSUS MEMBERS DIVERGE IN SOLUTIONS
JUST A LITTLE BIT FURTHER TO A CROSS-TRACK SPREAD OF 131NM AND
ALONG-TRACK SPREAD OF 112NM. HENCEFORTH, THE FORECAST CONFIDENCE
FROM TAU 72 TO TAU 120 IS MEDIUM FOR BOTH TRACK AND INTENSITY.

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