WDPS32 PGTW 010300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09P (NINE) WARNING NR 
002//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.9S 152.5E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 405 NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA
   MOVEMENT PAST 6 HOURS: EASTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS AN ELONGATED
SYSTEM WITH ASYMMETRICAL LOW LEVEL BANDS AND A REGION OF DEEP
FLARING CONVECTION NEAR THE ASSESSED LOW LEVEL CIRCULATION CENTER
(LLCC). A 010020Z GPM 37GHZ MICROWAVE IMAGE DEPICTED THE
DISORGANIZED STRUCTURE TO GOOD EFFECT. A FALSE MICROWAVE EYE-LIKE
FEATURE IS EVIDENT FAR TO THE NORTHWEST, BURIED UNDER THE FLARING
CONVECTIVE ACTIVITY, WHILE A WEAKER LOW EMISSIVITY REGION
SURROUNDED BY SHALLOW CURVED BANDING IS PRESENT FURTHER TO THE
SOUTHEAST. THIS FEATURE PROVIDED SUPPORT TO PLACEMENT OF THE
INITIAL POSITION, HOWEVER IN LIGHT OF THE WEAK NATURE OF THE
SIGNATURE AND THE OVERALL ELONGATED CENTER AND THE LARGE SPREAD IN
THE AGENCY FIX POSITIONS, THE INITIAL POSITION IS ASSESSED WITH LOW
CONFIDENCE. THE INITIAL INTENSITY REMAINS ASSESSED AT 35 KNOTS,
WITH MEDIUM CONFIDENCE, ABOVE THE BULK OF THE AGENCY CURRENT
INTENSITY ESTIMATES, BUT IN LINE WITH THE OBJECTIVE ADT ESTIMATES
OF T2.6. ANALYSIS REVEALS A MARGINAL ENVIRONMENT CHARACTERIZED BY
LOW SOUTHEASTERLY VERTICAL WIND SHEAR (VWS) AND WARM SSTS OFFSET BY
GENERALLY WEAK POLEWARD OUTFLOW ALOFT AND ENTRAINMENT OF MID-LEVEL
DRY AIR FROM THE SOUTH.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SOUTHWEST PERIPHERY OF A DEEP LAYER
NEAR-EQUATORIAL RIDGE (NER). 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   ABRF: T2.5 - 35 KTS
   CIMSS ADT: 37 KTS AT 312340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: WEAK POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: LOW
   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 09P HAS CONTINUED TO STRUGGLE TO
CONSOLIDATE A WELL DEFINED LOW LEVEL CORE. DRY AIR ENTRAINMENT IN
THE MID-LEVELS COMBINED WITH PERSISTENT, THOUGH DECREASING,
SOUTHEASTERLY SHEAR BEING THE PRIMARY LIMITED FACTORS TO
CONSOLIDATION AND DEVELOPMENT. TC 09P IS FORECAST TO CONTINUE TO
TRACK GENERALLY EASTWARD FOR THE NEXT 12 TO 24 HOURS ALONG THE
SOUTHWEST PERIPHERY OF THE NER CENTERED TO THE NORTHEAST. THE
SYSTEM WILL GRADUALLY TURN ONTO A MORE SOUTHEASTWARD TRACK AFTER
TAU 24 AS THE SYSTEM TRACKS ALONG THE GRADIENT BETWEEN THE NER AND
A DEVELOPING DEEP CUTOFF LOW WHICH IS EXPECTED TO DEVELOP JUST
SOUTH OF NEW CALEDONIA BY TAU 48. IN THE NEAR-TERM TC 09P IS NOT
EXPECTED TO INTENSIFY, MAINTAINING CURRENT INTENSITY AS IT
STRUGGLES AGAINST THE MID-LEVEL DRY AIR AND PERSISTENT SHEAR. AFTER
TAU 36 THE SYSTEM WILL MOVE INTO A MORE FAVORABLE OUTFLOW
ENVIRONMENT, TAPPING INTO STRONGER DIVERGENT POLEWARD OUTFLOW AND
DECREASED SHEAR, WHILE THE ATMOSPHERE MOISTENS SIMULTANEOUSLY,
ALLOWING FOR STEADY INTENSIFICATION TO A PEAK OF 55 KNOTS BY TAU
96. 

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE, WHILE STILL SHOWING
A FAIR AMOUNT OF SPREAD, HAS COME INTO BETTER AGREEMENT ON THE
OVERALL TRACK, AT LEAST THROUGH TAU 120. THE MODEL SPREAD DOES
INCREASE MODERATELY AFTER TAU 24, TO 200NM AT TAU 72 AND 475NM AT
TAU 120 BETWEEN UKMET ON THE POLEWARD SIDE AND GFS ON THE
EQUATORWARD. CONSISTENT WITH THE PREVIOUS RUN, THE REMAINDER OF THE
GUIDANCE PACKAGE REMAINS IN A SMALLER ENVELOPE WITH THE CONSENSUS
MEAN MARKING THE SOUTHERN EDGE OF THIS SMALLER ENVELOPE. ENSEMBLE
GUIDANCE MEANS REMAIN CONSISTENT WITH ONE ANOTHER BUT ALSO SHOW A
LARGE AMOUNT OF SPREAD, WITH THE MAJORITY OF THE GFS ENSEMBLE
MEMBERS FAVORING A TRACK MORE EQUATORWARD TOWARDS VANUATU. THE JTWC
FORECAST REMAINS CONSISTENT WITH THE PREVIOUS FORECAST, ON THE
NORTHERN EDGE OF THE TIGHTER GROUPING OF MODELS, CLOSEST TO THE
ECMWF ENSEMBLE MEAN, WITH LOW CONFIDENCE DUE TO THE UNCERTAINTY IN
THE INITIAL POSITION AND LARGE SPREAD IN BOTH THE DETERMINISTIC AND
ENSEMBLE GUIDANCE. INTENSITY GUIDANCE REMAINS MIXED, WITH A
GUIDANCE SUGGESTING A PEAK BETWEEN 40 AND 75 KNOTS. THE JTWC
FORECAST LIES VERY CLOSE TO THE HWRF AND CONSENSUS MEAN SOLUTIONS,
WITH LOW CONFIDENCE.  

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