WDXS31 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 31P (THIRTYONE) 
WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 10.4S 134.1E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 226 NM EAST-NORTHEAST OF DARWIN, AUSTRALIA
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
FEW SNAPSHOTS OF SUN WITH ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS LOW-LEVEL CLOUD BANDING WRAPPING INTO THE LLCC.
VERTICAL WIND SHEAR FROM THE EAST-NORTHEAST ENCROACHES ON THE DEEP
CONVECTION PARTIALLY OBSCURING THE LLCC. WATER VAPOR IMAGERY
REVEALS MODERATE POLEWARD AND EQUATORWARD OUTFLOW AS THE
ENVIRONMENT HAS IMPROVED SLIGHTLY OVER THE LAST SIX HOURS. CLOUD
TEMPERATURES HAVE ALSO BEGUN TO COOL, HINTING AT THE OVERALL
IMPROVEMENT TO A MORE FAVORABLE ENVIRONMENT. THE INITIAL POSITION
IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED ANIMATED
MSI DEPICTING THE PARTIALLY OBSCURED LLCC ACCOMPANIED BY A 222108Z
F-17 SSMIS 89GHZ MICROWAVE IMAGE DEPICTING A WEAK LLCC UPSTREAM OF
THE TRACK.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: ON THE NORTHERN PERIPHERY OF THE NEAR
EQUATORIAL RIDGE POSITIONED OVER WYNDHAM, AUSTRALIA EXTENDING
NORTHWESTWARD INTO THE TIMOR SEA.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   KNES: T1.5 - 25 KTS
   CIMSS ADT: 45 KTS AT 212340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: TROPICAL CYCLONE (TC) 31P IS SLIGHTLY
IN A MORE FAVORABLE ENVIRONMENT FOR THE SYSTEM TO REACH WARNING
THRESHOLD (35KTS) THAN IN THE PREVIOUS FORECAST.

FORECAST DISCUSSION: TC 31P WILL CONTINUE MOVING WEST-NORTHWESTWARD
UNDER THE STEERING INFLUENCE OF A NEAR EQUATORIAL RIDGE TO THE
SOUTH. THE TRACK MAY BE SLIGHTLY NORTHWARD OR SOUTHWARD BASED ON
THE VERTICAL EXTENT OF THE SYSTEM AS SLIGHT REINTENSIFICATION
OCCURS OVER THE NEXT 48 HOURS AND IS STEERED ON VARYING LEVELS OF
THE ATMOSPHERE. THE ENVIRONMENT WILL BE SLIGHTLY FAVORABLE FOR
INTENSIFICATION WITH LOW VERTICAL WIND SHEAR OF 5-10KTS, WARM SEA
SURFACE TEMPERATURES, AND UPPER-LEVEL DIVERGENCE WHICH WILL ALLOW
FOR A PEAK OF 35KTS WITHIN THE NEXT 12 HOURS. AFTER 36 HOURS, THE
SYSTEM WILL INTERACT WITH MODERATE VERTICAL WIND SHEAR (10-15KTS)
AND THE UPPER-LEVEL ENVIRONMENT WILL BECOME CONFUSED, LEADING TO A
WEAKENING TREND BELOW WARNING THRESHOLD BY TAU 48. A SMALL FACTOR
AS THE SYSTEM MOVES EQUATORWARD WILL BE A LOSS OF PLANETARY
VORTICITY, HOWEVER, THE ENVIRONMENT WOULD QUASH THE CIRCULATION
BEFORE THE SYSTEM DISSIPATES AS A RESULT.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN STRONG
AGREEMENT THAT THE SYSTEM WILL TRACK WEST-NORTHWESTWARD UNDER THE
STEERING INFLUENCE OF A NEAR EQUATORIAL RIDGE TO THE SOUTH. THE
TRACK SPREAD BY THE END OF THE FORECAST IS 80NM WITH NAVGEM TO THE
NORTH AND HWRF TO THE SOUTH. THE INTENSITY GUIDANCE GENERALLY
INDICATES A STRENGTHENING TREND, WHICH REFLECTS THE AFOREMENTIONED
INCREASINGLY FAVORABLE ENVIRONMENT. HOWEVER, GFS INDICATES A PEAK
OF 40KTS BY TAU 24, WHICH IS SLIGHTLY HIGHER THAN THE REST OF THE
MULTI-MODEL CONSENSUS.

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