WDPS31 PGTW 230300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 07P (SEVEN) WARNING NR 
001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.6S 153.7E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 454 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE 07P IS FINALLY COMING TOGETHER. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS DEEP CONVECTION
CONSOLIDATING AND BREAKING AWAY FROM THE LINEAR MONSOONAL BANDING
OVER THE CORAL SEA. HI-RESOLUTION VISUAL IMAGERY VERIFIES THAT THE
SOUTHERLIES ALONG THE WESTERN FLANK OF THE LOW LEVEL CIRCULATION
CENTER (LLCC) ARE FINALLY MAKING THE TURN AND WRAPPING INTO THE
SYSTEM. TOTAL PRECIPITABLE WATER LOOPS ALSO SHOW THE TELL-TALE
FISHHOOK SIGNATURE AT THE SOUTHWESTERN MOST PERIPHERY OF THE DEEP
CONVECTION.  A DIRECT OVERHEAD SCATTEROMETRY PASS AT 222243Z 
CONFIRMS THE CLOSED CIRCULATION AND POSITIONING. THE STORM IS IN A
TENUOUS ZONE FOR DEVELOPMENT, POSITIONED UNDER A NARROW BELT OF
VERY LOW VERTICAL WIND SHEAR (VWS) SURROUNDED BY VERY HIGH VWS ON
EITHER SIDE OF THE ZONE. THE POSITION IS FIXED BASED ON THE
SCATTEROMETRY AND THE JTWC FIX ON THE PARTLY EXPOSED LLCC. THE
INTENSITY ASSESSMENT IS BASED ON THE SCATTEROMETRY AND SUPPORTED BY
THE JTWC T2.5 DVORAK. THE BRISBANE FIX ALSO RECENTLY CAME IN AT
2.5.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA FROM 222243Z. 

CURRENT STEERING MECHANISM: THE SUBTROPICAL RIDGE TO THE
NORTH-NORTHEAST WILL NUDGE THE SYSTEM WESTWARD WHILE AN ANTICYCLONE
OVER THE LAKE EYRE BASIN WILL KEEP THE NORTH OF THE 20TH LATITUDE. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.0 - 30 KTS
   ABRF: T2.5 - 35 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 0-5 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TROPICAL CYCLONE 07P WILL BREAK AWAY FROM
THE MONSOON TROF OVER THE NEXT TWELVE HOURS AND EMBARK ON A STEADY
WEST-SOUTHWESTERLY BEARING TOWARDS THE COAST JUST SOUTH OF 
TOWNSVILLE. TRACK GUIDANCE INDICATES THE SYSTEM WILL REMAIN UNDER A 
NARROW ALLEY OF LOW VWS AND MANAGE TO DEVELOP STEADILY THROUGH LOW 
TYPHOON STRENGTH 12 HOURS PRIOR TO LANDFALL. SEA SURFACE TEMPERATURES 
AND OCEAN HEAT CONTENT ALONG TRACK ARE EXCELLENT FOR DEVELOPMENT BUT 
A BELT OF DRY SOUTHEASTERLIES BETWEEN THE COAST AND THE STORM COUPLED 
WITH SUPPRESSED OUTFLOW ALONG THE WESTERN FLANK WILL COMBINE TO KEEP 
THE STORM DEVELOPING AT OR BELOW A CLIMATOLOGICAL AVERAGE RATE. 
ANIMATED WATER VAPOR IMAGERY SHOWS SUBSTANTIAL SUBSIDENCE IN THE 
UPPER LEVELS BETWEEN THE COAST AND THE STORM BUT MODERATE EQUATORWARD 
OUTFLOW OVER THE NORTHEAST QUADRANT. DUE TO THE HIGH VERTICAL 
WIND SHEAR SURROUNDING THE STORM AND THE DRY AIR ENTRAINMENT ON THE 
WESTERN FLANK THE GALE FORCE WINDFIELDS ARE EXPECTED TO BE SMALLER 
THAN AVERAGE DURING THE LIFE OF THE SYSTEM. 

MODEL DISCUSSION: TRACK GUIDANCE SHOWS A MILD AMOUNT OF ALONG-TRACK
SPREAD BUT GOOD GENERAL AGREEMENT ON THE SCENARIO OF LANDFALL JUST
SOUTH OF TOWNSVILLE. TIMING IS ALSO CONSISTENT AND THE JTWC
FORECAST STAYS CLOSE TO THE MULTI-MODEL CONSENSUS. THERE IS ONE RI
MODEL TRIGGERING BUT THE STATISTICAL-DYNAMICAL GUIDANCE (SHIPS)
FROM THE GFS MODEL MAKES THE MOST SENSE. THE FORECAST RIDES A TICK
ABOVE CONSENSUS STAYING CLOSER TO THE SHIPS GUIDANCE. 

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