WDPN32 PGTW 141500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (MAN-YI) WARNING NR 
023//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 10.6N 135.0E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 854 NM EAST-SOUTHEAST OF MANILA,
                         PHILIPPINES
   MOVEMENT PAST 6 HOURS: WESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 
CONSOLIDATING SYSTEM, WITH DEEP CONVECTIVE BANDING OVER THE SOUTHERN 
AND EASTERN SEMICIRCLES WRAPPING INTO A RAGGED LOW-LEVEL CIRCULATION 
CENTER (LLCC). A 141048Z TMS 91GHZ MICROWAVE IMAGE REVEALS IMPROVED 
CONVECTIVE BANDING WRAPPING INTO A DEFINED LLCC, WHICH SUPPORTS THE 
INITIAL POSITION WITH MEDIUM CONFIDENCE. RECENT ASCAT DATA SHOWS 
EXTENSIVE GALE-FORCE WINDS OVER THE EASTERN SEMICIRCLE, WITH ISOLATED 
50 KNOT WINDS OVER THE NORTHEAST QUADRANT. THE INITIAL INTENSITY OF 
55 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE PGTW AND TCTP 
DVORAK ESTIMATES OF T3.5 (55 KNOTS).

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: STRONG SUBTROPICAL RIDGE (STR)
ENTRENCHED TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RCTP: T3.5 - 55 KTS
   CIMSS ADT: 45 KTS AT 141130Z
   CIMSS AIDT: 37 KTS AT 141130Z
   CIMSS D-PRINT: 53 KTS AT 141130Z

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

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 STORM (TS) 25W WILL TRACK WESTWARD TO
WEST-NORTHWESTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING
INFLUENCE OF THE STR. ENVIRONMENTAL CONDITIONS WILL BE HIGHLY
CONDUCIVE FOR RAPID INTENSIFICATION, AS REVEALED IN BOTH THE
DETERMINISTIC AND PROBABILISTIC MODEL GUIDANCE, WITH A POOL OF VERY
HIGH OCEAN HEAT CONTENT AVAILABLE THROUGH TAU 48. AFTER THE SYSTEM
CROSSES LUZON AND TRACKS BACK OVER THE SOUTH CHINA SEA, INCREASING
VERTICAL WIND SHEAR AND DRY AIR ENTRAINMENT WILL SERVE TO STEADILY
WEAKEN THE SYSTEM THROUGH TAU 120.  

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE IS IN TIGHT AGREEMENT 
THROUGH TAU 72, WITH A 105NM CROSS-TRACK SPREAD IN SOLUTIONS. AFTER 
TAU 72, GUIDANCE DIVERGES WITH A 120NM CROSS-TRACK SPREAD AT TAU 120. 
THE 140600Z ECMWF ENSEMBLE (EPS) AND THE 140000Z GFS ENSEMBLE (GEFS) 
REMAIN IN TIGHT AGREEMENT SUPPORTING THE JTWC TRACK FORECAST WITH 
HIGH CONFIDENCE THROUGH TAU 72. GEFS INDICATES RAPID WEAKENING OVER 
THE SOUTH CHINA SEA AND INCREASING UNCERTAINTY AFTER TAU 72, WITH 
SOLUTIONS DIVERGING FROM SOUTHERN VIETNAM TO HAINAN ISLAND AT 
TROPICAL DEPRESSION STRENGTH. THE 140000Z COAMPS-TC ENSEMBLE 
(CTCXEPS) INTENSITY PROBABILITY CHART INDICATES PEAK 60-70 PERCENT 
PROBABILITY FOR RAPID INTENSIFICATION (RI) FROM TAU 6 TO TAU 42. 
RELIABLE DETERMINISTIC INTENSITY GUIDANCE COMPRISING THE JTWC 
INTENSITY CONSENSUS ALSO SHOWS STRONG SUPPORT FOR RI THROUGH TAU 48, 
WITH HAFS-A AND COAMPS-TC (GFS) PEAKING AT 110-115 KNOTS BY TAU 48.  

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