WDPS31 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02P (MAL) WARNING NR 
002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 11.1S 171.8E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 568 NM NORTHWEST OF SUVA, FIJI
   MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 18 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RAPIDLY
CONSOLIDATING TROPICAL CYCLONE, WITH CONVECTIVE HOT TOWERS FIRING
OFF AROUND THE ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC), WHICH
REMAINS OBSCURED IN THE MSI AND INFRARED IMAGERY. A FORTUITOUS
130553Z SSMIS 89GHZ MICROWAVE IMAGE REVEALED A NASCENT MICROWAVE
EYE FEATURE AND WELL-DEFINED CONVECTIVE BANDING FEATURES TO THE
NORTHEAST AND SOUTHWEST, WRAPPING INTO THE DEVELOPING CORE.
CONFIDENCE IN THE INITIAL POSITION IS ASSESSED AS MEDIUM DUE TO
LIKELY VORTEX TILT DUE TO MODERATE MID- TO UPPER-LEVEL SHEAR FROM
THE NORTHEAST. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
CONFIDENCE, PUSHED HIGHER THAN THE BULK OF THE AGENCY DVORAK
INTENSITY ESTIMATES IN LIGHT OF THE HIGHER KNES ESTIMATE WHICH
LINES UP EXACTLY WITH THE INITIAL POSITION, THE CIMSS ADT, DPRINT
AND DMINT ESTIMATES AS WELL AS THE NASCENT MICROWAVE EYE FEATURE.
THE SYSTEM HAS BEGUN TO ACCELERATE SOUTHEASTWARD ALONG THE WESTERN
SIDE OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED TO THE EAST.
ENVIRONMENTAL CONDITIONS ARE FAVORABLE FOR CONTINUED DEVELOPMENT,
WITH WARM SSTS, HIGH OCEAN HEAT CONTENT (OHC), STRONG POLEWARD
OUTFLOW AND LOW DEEP-LAYER VERTICAL WIND SHEAR.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER STR
CENTERED TO THE EAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T3.0 - 45 KTS
   PHFO: T2.5 - 35 KTS
   CIMSS ADT: 47 KTS AT 130530Z
   CIMSS DPRINT: 50 KTS AT 130600Z
   CIMSS DMINT: 46 KTS AT 130555Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG 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: TROPICAL CYCLONE (TC) 02P (MAL) IS RAPIDLY
CONSOLIDATING AND INTENSIFYING AS IT BEGINS TO TRACK SOUTHEAST
TOWARDS A RENDEZVOUS WITH FIJI. THE SYSTEM IS FORECAST TO TRACK
SOUTHEASTWARD ALONG THE WEST-SOUTHWEST SIDE OF THE STEERING RIDGE
THROUGH THE ENTIRETY OF THE FORECAST PERIOD, PROVIDING FOR A HIGH
CONFIDENCE TRACK FORECAST WHICH WILL SKIRT THE WEST SIDE OF THE
MAIN ISLAND OF VITI LEVU BETWEEN TAU 24 AND TAU 36. THE SYSTEM THEN
CONTINUES SOUTHEASTWARD INTO THE OPEN WATERS OF THE SOUTH PACIFIC
THROUGH THE REMAINDER OF THE FORECAST PERIOD. IN TERMS OF
INTENSITY, THE SYSTEM HAS ALREADY INTENSIFIED RATHER QUICKLY,
HAVING INCREASED IN INTENSITY FROM 30 KNOTS TO AT LEAST 45 KNOTS IN
THE PAST 12 HOURS. CONDITIONS ARE EXPECTED TO REMAIN FAVORABLE FOR
THE NEXT 36 HOURS, ALLOWING FOR THE SYSTEM TO CONTINUE TO
STRENGTHEN UP TO AT LEAST 65 KNOTS BY TAU 24. SOME MODEL GUIDANCE
SUGGESTS THE SYSTEM COULD UNDERGO RAPID INTENSIFICATION (RI) OVER
THE NEXT 24 HOURS. THIS IS A LOW-PROBABILITY SCENARIO AT PRESENT,
BUT IF THE VORTICAL HOT TOWERS (VHTS) CURRENTLY FIRING NEAR THE
CENTER ARE ABLE TO WRAP UPSHEAR AND FURTHER CONSOLIDATE AND ALIGN
THE INNER CORE OF THE SYSTEM, THE SYSTEM COULD CERTAINLY UNDERGO RI
AND REACH A HIGHER PEAK INTENSITY. REGARDLESS, THE PEAK INTENSITY
WILL OCCUR AS THE SYSTEM IS PASSING WEST OF FIJI. AFTER PASSING 20S
LATITUDE, AROUND TAU 48, THE SYSTEM MOVES ACROSS THE 26C ISOTHERM
INTO MUCH COOLER WATERS, IS ENVELOPED IN EXTREMELY DRY MID-LEVEL
AIR, AND EXPERIENCES A DRASTIC INCREASE IN WESTERLY SHEAR WHICH
WILL DECAPITATE THE CYCLONE. THIS ALSO MARKS THE ONSET OF A RAPID
SUBTROPICAL TRANSITION (STT), WHICH IS FORECAST TO BE COMPLETE NO
LATER THAN TAU 96. 

MODEL DISCUSSION: DETERMINISTIC AND ENSEMBLE TRACK GUIDANCE IS IN
VERY GOOD AGREEMENT, WITH THE ONE NOTABLE EXCEPTION OF NAVGEM WHICH
IS A SIGNIFICANT OUTLIER TO THE WEST. DISCOUNTING THE NAVGEM, THE
REMAINDER OF THE TRACK GUIDANCE IS CONSTRAINED TO A VERY TIGHT
ENVELOPE OF JUST 105NM AT TAU 72, WIDENING SLIGHTLY TO 150NM BY THE
END OF THE FORECAST AT TAU 96. THUS THE TRACK IS LAID WITH HIGH
CONFIDENCE AND REMAINS CONSISTENT WITH THE PREVIOUS FORECAST AND
THE CONSENSUS MEAN. INTENSITY GUIDANCE IS MIXED AND SHOWS A FAIRLY
LARGE AMOUNT OF SPREAD. ON THE HIGH END OF THE ENVELOPE ARE THE
DECAY SHIPS (GFS AND NAVGEM), WHICH PEAK THE SYSTEM BETWEEN 65-75
KNOTS, AS WELL AS THE RIPA RI AID WHICH PEAKS AT 85 KNOTS IN 24
HOURS. THE CONSENSUS MEAN, HWRF, HAFS-A AND COAMPS-TC MEANWHILE
SHOW PEAK INTENSITY BETWEEN 50-60 KNOTS. THE JTWC FORECAST LIES
SLIGHTLY BELOW THE MOST AGGRESSIVE MODELS BUT ABOUT 10 KNOTS ABOVE
THE MEAN. AS NOTED ABOVE, THE POSSIBILITY OF RI CANNOT BE
DISCOUNTED, THOUGH IT REMAINS A LOW PROBABILITY SCENARIO AT THE
CURRENT TIME. 

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