WDXS33 PGTW 062100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 14S (TALIAH)     
WARNING NR 012//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 14.5S 101.5E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 302 NM EAST-SOUTHEAST OF THE COCOS ISLANDS
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 31 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A LARGE
CLUSTER OF DEEP CONVECTION PERSISTING OVER THE WESTERN SEMICIRCLE OF A 
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION (LLC). A 061426Z MHS 89GHZ 
MICROWAVE IMAGE REVEALS CURVED BANDING AND A POSSIBLE UPPER-LEVEL 
CIRCULATION CENTER TILTED WEST OF THE LOW-LEVEL CIRCULATION CENTER DUE 
TO HIGH EASTERLY VERTICAL WIND SHEAR (VWS). ENVIRONMENTAL CONDITIONS 
REMAIN MARGINALLY FAVORABLE WITH THE HIGH VWS AND DRY AIR ENTRAINMENT 
HINDERING DEVELOPMENT. HOWEVER, EQUATORWARD OUTFLOW HAS CLEARLY 
IMPROVED OVER THE PAST DAY, WITH A GRADUAL DECREASE IN VWS. THE 
INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE 
ANIMATED EIR IMAGERY AND A 061426Z ASCAT-C BULLSEYE IMAGE, WHICH SHOWS 
AN ELONGATED BUT WELL-DEFINED CENTER. THE INITIAL INTENSITY OF 60 KTS 
IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON AN AVERAGE OF THE AGENCY 
FIXES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
POSITIONED TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   KNES: T4.0 - 65 KTS
   DEMS: T3.5 - 55 KTS
   APRF: T3.5 - 55 KTS
   CIMSS SATCON: 52 KTS AT 061603Z
   CIMSS ADT: 45 KTS AT 061800Z
   CIMSS AIDT: 54 KTS AT 061800Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 27-28 CELSIUS
   OUTFLOW: STRONG EQUATORWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT 

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) 14S WILL TRACK WEST-
SOUTHWESTWARD THROUGH TAU 36 UNDER THE STEERING INFLUENCE OF THE STR 
POSITIONED TO THE SOUTH. AFTER TAU 36, A SERIES OF MAJOR SHORTWAVE 
TROUGHS WILL WEAKEN THE STR LEADING A VERY COMPLEX, EVOLVING STEERING 
PATTERN. A WEAK STR TO THE WEST OF THE SYSTEM WILL DRIVE THE SYSTEM 
WEST-NORTHWESTWARD THROUGH TAU 72. AFTER TAU 72, THE WESTERN STR WILL 
ERODE, WITH A STR BUILDING TO THE SOUTH, WHICH WILL TURN THE SYSTEM 
WESTWARD THROUGH TAU 120. VWS IS FORECAST TO RELAX AFTER TAU 36, WITH 
RE-MOISTENING OF THE SYSTEM'S CORE, WHICH WILL PRODUCE STEADY RE-
INTENSIFICATION THROUGH TAU 96 TO A PEAK OF 80 KNOTS.     

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, THE DETERMINISTIC
GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72, WITH A 45NM TO 65NM
CROSS-TRACK SPREAD IN SOLUTIONS FROM TAU 48 TO TAU 72. THE 061200Z
EPS AND GEFS ENSEMBLES ARE ALSO IN GOOD AGREEMENT THROUGH TAU 72
LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. AFTER TAU 72,
THERE IS A LARGE SPREAD IN BOTH THE DETERMINISTIC AND PROBABILISTIC
GUIDANCE, WITH LOW CONFIDENCE IN THE EXTENDED JTWC TRACK FORECAST. 
 
FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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