WDXS31 PGTW 162100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 02S (BHEKI) WARNING NR 
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.2S 71.7E
   INITIAL INTENSITY: 100 KTS
   GEOGRAPHIC REFERENCE: 874 NM EAST-NORTHEAST OF PORT LOUIS,
MAURITIUS
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
CYCLONE 02S (BHEKI) WITH A NEWLY DEVELOPED, DEFINED EYE AND
SYMMETRIC CENTRAL DENSE OVERCAST OVER THE EYEWALL. 02S IS ANALYZED
TO HAVE UNDERGONE RAPID INTENSIFICATION OVER THE PAST 24 HOURS
(65-100 KTS). ENVIRONMENTAL ANALYSIS INDICATES THAT 02S IS IN A
FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG POLEWARD OUTFLOW
ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND WARM (27-28 C) SEA
SURFACE TEMPERATURES. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE EYE IN ANIMATED EIR IMAGERY. THE INITIAL
INTENSITY OF 100 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON
THE AGENCY DVORAK AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.
ADDITIONALLY, A 161337 RCM-2 SAR IMAGE SHOWS A MAX OF 90 KTS AND
THE SYSTEM HAS STRENGTHENED SINCE THEN.

INITIAL WIND RADII BASIS: SAR DATA 

CURRENT STEERING MECHANISM: NORTHWESTERN PERIPHERY OF A SUBTROPICAL
RIDGE (STR) POSITIONED TO THE EAST-SOUTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.5 - 102 KTS
   KNES: T5.5 - 102 KTS
   DEMS: T5.5 - 102 KTS
   FMEE: T5.0 - 90 KTS
   CIMSS ADT: 94 KTS AT 161800Z
   CIMSS AIDT: 91 KTS AT 161800Z
   CIMSS DPRINT: 90 KTS AT 161830Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: 02S IS FORECAST TO CONTINUE TRACKING
SOUTHWESTWARD THROUGH TAU 36 ALONG THE NORTHWESTERN PERIPHERY OF
THE STR. TRACK SPEEDS ARE EXPECTED TO SLOW AS A BREAK IN THE RIDGE
ENSUES. NEAR TAU 48, RIDGING IS EXPECTED TO BUILD TO THE SOUTH OF
THE SYSTEM AND WILL DRIVE IT GENERALLY WESTWARD THROUGH THE
REMAINDER OF THE FORECAST PERIOD. REGARDING INTENSITY, 02S IS
EXPECTED TO MAINTAIN INTENSITY OVER THE NEXT 12 HOURS. AFTER TAU
12, SEA SURFACE TEMPERATURES WILL BEGIN TO COOL AND VERTICAL WIND
SHEAR WILL INCREASE TO AROUND 25-30 KTS. THESE TWO FACTORS WILL
CAUSE 02S TO WEAKEN QUICKLY FROM TAU 12 TO TAU 48. AFTER TAU 48, A
STEADY WEAKENING TREND IS FORECAST AS IT TRACKS WESTWARD AND
APPROACHES MADAGASCAR, NEARING TROPICAL DEPRESSION STRENGTH NEAR
THE END OF THE FORECAST PERIOD. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
REGARDING THE TRACK OF 02S THROUGH TAU 36. AFTER TAU 36, MODELS
QUICKLY DIVERGE TO A 160 NM CROSS-TRACK SPREAD AT TAU 48. SPREAD
CONTINUES TO OPEN THROUGH TAU 120 WITH POSITIONS RANGING FROM 14S
TO 22S LATITUDES. GALWEM MAKES UP THE NORTHERNMOST MEMBER OF
GUIDANCE WHILE ECMWF MAKES UP THE SOUTHERNMOST MEMBER.  THE JTWC
TRACK FORECAST IS PLACED CLOSE TO CONSENSUS WITH MEDIUM CONFIDENCE
THROUGH TAU 72 AND LOW CONFIDENCE THEREAFTER. INTENSITY GUIDANCE IS
IN MODERATE AGREEMENT THROUGHOUT THE FORECAST PERIOD. HAFS-A KEEPS
THE VORTEX STRONGER THAN HWRF, COAMPS-TC, AND GFS THOUGH. THE JTWC
INTENSITY FORECAST IS PLACED CLOSE TO CONSENSUS WITH OVERALL MEDIUM
CONFIDENCE.

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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