WDPS31 PGTW 230900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 07P (SEVEN)      
WARNING NR 002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.1S 153.6E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 448 NM EAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: SOUTH-SOUTHWESTWARD AT 06 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL CYCLONE (TC) 07P HAS CONTINUED TO STRUGGLE TO ORGANIZE DUE
TO THE BROAD UPPER-LEVEL LOW POSITIONED OVER THE CENTER, EXTENDING
WESTWARD TO THE AUSTRALIAN GOLD COAST. CONSEQUENTLY, ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS MULTIPLE MESOVORTICIES 
ROTATING CYCLONICALLY AROUND A BROAD, EXPOSED CENTER, WITH DEEP 
CONVECTIVE BANDING DISPLACED EASTWARD AND POLEWARD. A 230319Z AMSR2 36 
GHZ MICROWAVE IMAGE REVEALS A FAIRLY RAGGED LOW-LEVEL CIRCULATION 
CENTER (LLCC) WITH FRAGMENTED INNER SHALLOW BANDING WRAPPING AROUND 
THE LLCC. A RECENT 222243Z ASCAT-B IMAGE REFLECTS THE BROAD NATURE OF 
THE SYSTEM, SHOWING AN ELONGATED CENTER WITH GALE-FORCE WINDS 
DISPLACED TO THE NORTHEAST AND SOUTHWEST. THIS ASCAT IMAGE WAS USED TO 
TAILOR THE INITIAL WIND RADII VALUES. OVERALL, THE INITIAL POSITION IS 
PLACED WITH MEDIUM CONFIDENCE BASED ON THE CENTROID POSITION EVIDENT 
IN MSI AND THE AMSR2 IMAGE. THE INITIAL INTENSITY OF 35 KTS IS 
ASSESSED WITH HIGH CONFIDENCE BASED ON SUBJECTIVE DVORAK ESTIMATES, 
RECENT ASCAT DATA AND THE CIMSS OBJECTIVE ESTIMATES.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA 

CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT WITH
SUBTROPICAL RIDGES POSITIONED TO THE EAST AND WEST.   

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.0 - 30 KTS
   ABRF: T2.5 - 35 KTS
   CIMSS ADT: 35 KTS AT 230600Z
   CIMSS AIDT: 33 KTS AT 230600Z
  
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   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 07P IS TRACKING SLOWLY WITHIN A COMPETING
STEERING ENVIRONMENT BUT IS FORECASTED TO TURN WEST-SOUTHWESTWARD
AFTER TAU 12 AS THE SUBTROPICAL RIDGE TO THE WEST, OVER EASTERN
AUSTRALIA, BUILDS TO THE SOUTH AND BECOMES THE DOMINANT STEERING
INFLUENCE THROUGH THE FORECAST PERIOD. OVER THE NEXT DAY, THE
UPPER-LEVEL LOW IS EXPECTED TO GRADUALLY ERODE, REPLACED BY
UPPER-LEVEL RIDGING. THIS WILL ALLOW THE SYSTEM TO INTENSIFY AT A
FASTER RATE TO A PEAK INTENSITY OF 60 KNOTS JUST PRIOR TO LANDFALL
NEAR TAU 48. AFTER TAU 48, THE SYSTEM WILL RAPIDLY WEAKEN AS IT
TRACKS INLAND, WITH DISSIPATION ANTICIPATED BY TAU 72.       

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT WITH A CROSS-TRACK SPREAD OF ONLY 60 NM AT TAU 48.
HOWEVER, SIGNIFICANT UNCERTAINTY IN THE INITIAL POSITION WILL
CONTINUE THROUGH TAU 24 THUS OVERALL CONFIDENCE IN THE JTWC TRACK
FORECAST IS MEDIUM. DUE TO THE COMPLEX, EVOLVING UPPER-LEVEL
ENVIRONMENT, THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY
FORECAST. RELIABLE INTENSITY GUIDANCE, INCLUDING THE HAFS-A AND
COAMPS-TC FORECASTS, INDICATES A PEAK INTENSITY RANGING FROM 45 TO
60 KNOTS. THE 221800Z COAMPS-TC ENSEMBLE INTENSITY PROBABILITIES
SHOW LOW PROBABILITY (20 TO 30 PERCENT) OF MODERATE INTENSIFICATION 
OVER THE NEXT TWO DAYS.   

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