WDPS31 PGTW 130300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 03P (JASPER) WARNING 
NR 033//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.7S 146.4E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 80 NM NORTH-NORTHEAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: WESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND RADAR IMAGERY
FROM CAIRNS, AUSTRALIA DEPICTS AN ORGANIZING CYCLONE WITH SPIRAL
BANDING WRAPPING MORE SYMMETRICALLY AROUND BOTH NORTHERN AND
SOUTHERN SEMICIRCLES RELATIVE TO SIX HOURS AGO. ALTHOUGH AN
EYE-LIKE DRY REGION EXISTS AT THE CENTER OF CIRCULATION, THE
COLDEST CLOUD TOPS (COLDER THAN -70 DEGREES CELSIUS) REMAIN SPARSE,
OVERALL CENTRAL COLD RING TEMPERATURE REMAINS RATHER WARM, AND
RADAR IMAGERY SHOWS THAT A CLOSED INNER CONVECTIVE RING HAS NOT YET
MATERIALIZED. THESE TRENDS ARE ALL INDICATIVE OF A STRENGTHENING
CYCLONE, BUT ONE THAT IS LIKELY BELOW TYPHOON INTENSITY. THE
INITIAL INTENSITY IS RAISED TO 55 KT BASED ON RISING AGENCY DVORAK
ESTIMATES OF T3.5 FROM PGTW, ABRM, AND KNES. MAXIMUM WIND GUSTS AT
BOUGAINVILLE REEF OVER THE PAST SIX HOURS WERE 46 KT. STORM MOTION
HAS ACCELERATED SLIGHTLY, JUST SOUTH OF DUE WEST, NEARLY
PERPENDICULAR TO THE AUSTRALIAN COASTLINE, AND THE CYCLONE IS NOW
ABOUT 60 NM OFFSHORE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T3.5 - 55 KTS
   CIMSS ADT: 33 KTS AT 122330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE EASTWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: TROPICAL CYCLONE 03P (JASPER) IS NOW
ACCELERATING SLIGHTLY WESTWARD OR WEST-SOUTHWESTWARD TOWARD THE
COASTLINE OF QUEENSLAND, AND IS EXPECTED TO MAKE LANDFALL IN LESS
THAN 12 HOURS. AS EXPECTED BY THE PREVIOUS FORECAST, SOME
INTENSIFICATION IS OCCURRING AS DEEP CONVECTION REDEVELOPS AND
EXPANDS IN COVERAGE WITHIN THE COMPACT CORE WIND FIELD. THOUGH NOT
REFLECTED IN THE JTWC FORECAST DUE TO THE SPACING OF THE FORECAST
POINTS, SOME ADDITIONAL INTENSIFICATION IS POSSIBLE PRIOR TO
LANDFALL. THE LANDFALL LOCATION IS OF HIGHER CONFIDENCE NOW THAT
SOME OF THE SOUTHERLY OUTLIER MODEL SOLUTIONS CLOSER TO CAIRNS HAVE
NOT MATERIALIZED DURING THE PAST SIX HOURS. THE CURRENT JTWC
FORECAST CROSSES THE COAST ABOUT 60 NM NORTH OF CAIRNS. A WESTWARD
TRACK OVER THE CAPE YORK PENINSULA WILL ENSUE ALONG THE NORTHERN
PERIPHERY OF THE SUBTROPICAL RIDGE, ACCOMPANIED BY STEADY WEAKENING
BELOW WARNING THRESHOLD. THIS TRACK WILL BRING THE REMNANTS OUT
OVER THE GULF OF CARPENTARIA BETWEEN 48 AND 72 HOURS, AT WHICH
POINT THEY WILL BE CLOSELY MONITORED FOR REGENERATION. A
COMBINATION OF WESTERLY VERTICAL SHEAR AND AMBIENT DRY AIR OVER THE
GULF OF CARPENTARIA MAY LIMIT THE PACE OF REINTENSIFICATION (IF
ANY), BUT SOME MODELS SUCH AS ECMWF AND THE ECMWF ENSEMBLE CONTINUE
TO INDICATE A CHANCE OF JASPER EVENTUALLY REATTAINING
WARNING-THRESHOLD INTENSITY.

MODEL DISCUSSION: THE JTWC TRACK AND INTENSITY FORECASTS ARE CLOSE
TO THE MULTI-MODEL CONSENSUS. THERE IS SOME MODEL DISAGREEMENT IN
HOW FAR SOUTH THE STORM WILL TRACK WHILE INLAND OVER THE CAPE YORK
PENINSULA, BUT THE MODEL CONSENSUS HAS NOT SHIFTED MUCH OVER THE
PAST SIX HOURS.

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