WDXS31 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 08S (CHENESO) WARNING 
NR 009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.6S 43.2E
   INITIAL INTENSITY: 75 KTS
   GEOGRAPHIC REFERENCE: 229 NM NORTHEAST OF EUROPA ISLAND
   MOVEMENT PAST 6 HOURS: EASTWARD AT 01 KTS
   SIGNIFICANT WAVE HEIGHT: 22 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 16NM
EYE FEATURE AND ASSOCIATED EYE WALL REGION EXHIBITING HIGHLY
CYCLICAL PERIODS OF CONSOLIDATION AND DETERIORATION. CURRENTLY IN A
DETERIORATION PHASE, A RECENT 252242Z AMSR2 89GHZ MICROWAVE IMAGE
DEPICTS AN EYE SURROUNDED BY A WEAK EYE WALL AND LACKLUSTER DEEP
CONVECTIVE BANDING. A 252240Z AMSR2 MICROWAVE RADIOMETER IMAGE
INDICATES 70-73KT WINDS EXIST IN THE EASTERN SEMICIRCLE OF THE
CIRCULATION. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON EIR AND AMSR2 IMAGERY. THE INITIAL INTENSITY OF 75 KTS IS
ASSESSED WITH LOW CONFIDENCE BASED ON THE BULK OF DVORAK AND
AUTOMATED INTENSITY ESTIMATES INDICATING UNREALISTIC RAPID
INTENSIFICATION NEAR 90-104KTS WHILE AMSR2 RADIOMETRY DATA AND
ANALYSIS OF EIR IMAGERY TELLS A DIFFERENT STORY.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN WITH A
NEAR-EQUATORIAL RIDGE (NER) POSITIONED TO THE NORTH AND A
SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   DEMS: T5.0 - 90 KTS
   FMEE: T5.0 - 90 KTS
   CIMSS SATCON: 84 KTS AT 252209Z
   CIMSS ADT: 104 KTS AT 252100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-30 CELSIUS
   OUTFLOW: STRONG RADIAL
   OTHER FACTORS: UPWELLING COOL WATER AND INTERACTION WITH
MADAGASCAR TO THE EAST

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TC 08S REMAINS IN A HIGHLY COMPLEX AND
COMPETING STEERING ENVIRONMENT WITH A NER POSITIONED TO THE NORTH
AND A STR ENTRENCHED TO THE SOUTH. DESPITE A RECENT AND SHORT-LIVED
NORTHEASTWARD TRACK, OVER THE COMING HOURS THE STR TO THE SOUTH IS
FORECAST TO BREAK DOWN ALLOWING POLEWARD MOVEMENT TO RESUME. AS THE
SYSTEM PROGRESSES TOWARDS EUROPA ISLAND, THE TWO PRIMARY LIMITING
FACTORS (UPWELLING OF COOL WATER AND LAND INTERACTION) WILL NO
LONGER BE IN PLAY. BY TAU 36, THE SYSTEM IS FORECAST TO REACH A
PEAK INTENSITY OF 100KTS. AS TC 08S BEGINS TO EXIT THE MOZAMBIQUE
CHANNEL NEAR TAU 48, THE STR TO THE SOUTH IS QUICKLY FORCED
WESTWARD DUE TO AN APPROACHING DEEP UPPER-LEVEL TROUGH, ALLOWING
THE SYSTEM TO ACCELERATE POLEWARD. BY TAU 72, THE SYSTEM WILL ALTER
COURSE TO THE SOUTH-SOUTHEAST AS THE APPROACHING TROUGH MOVES
EASTWARD. BY TAU 96, THE SYSTEM WILL HAVE BEGUN INTERACTING WITH
THE SUBTROPICAL WESTERLIES AND ASSOCIATED BAROCLINIC ENVIRONMENT
THEREBY STARTING SUB-TROPICAL TRANSITION (STT). THIS TRANSITION
WILL BE RAPID DUE TO THE SUB-TROPICAL AND MID-LATITUDE TROUGHS
BEING IN-PHASE, CREATING A STRONG TEMPERATURE GRADIENT AND THEREFOR
RAPID TRANSITION. BY TAU 120, HAVING ALREADY COMPLETED STT, TC 08S
WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT), AS THE INCREASINGLY
FRONTAL SYSTEM WEAKEN TO 55KTS.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THAT TC
08S WILL TRACK SOUTHWESTWARD THROUGH TAU 48 AND EVENTUALLY
SOUTHEASTWARD BY TAU 72 AND THROUGH THE FORECAST PERIOD. FOR THIS
REASON THE JTWC FORECAST TRACK IS PLACED WITH HIGH CONFIDENCE.
RELIABLE MODEL INTENSITY GUIDANCE IS IN POOR AGREEMENT, WITH
VARIOUS RAPID INTENSIFICATION (RI) AIDS AND HWRF INDICATING
WOEFULLY UNSUPPORTED RI IN THE NEAR TERM WHEN UPWELLING AND LAND
INTERACTION ARE NEGATING MUCH IF NOT ALL INTENSIFICATION.
DECAY-SHIPS (NVGM) AND GFS INDICATE WEAKENING WHICH IS ALSO
UNSUPPORTED GIVEN THE AFOREMENTIONED ENVIRONMENT AFTER POLEWARD
MOVEMENT IS REESTABLISHED. THE JTWC FORECAST INTENSITY IS THEREFOR
PLACED NEAR THE MULTI-MODEL CONSENSUS ALBEIT WITH LOW CONFIDENCE.

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