WDPN32 PGTW 040300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (MAYSAK) WARNING NR 
010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.2N 108.4E
   INITIAL INTENSITY: 45 KTS
   GEOGRAPHIC REFERENCE: 148 NM EAST-SOUTHEAST OF HANOI, VIETNAM
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
EVALUATION OF THE SYNOPTIC AND MESOSCALE ENVIRONMENT REVEALS A
MARGINALLY FAVORABLE THERMODYNAMIC AND KINEMATIC ENVIRONMENT,
CHARACTERIZED BY ELEVATED OCEANIC HEAT CONTENT WITH SEA SURFACE
TEMPERATURES OF 29-30 C, HIGH AVAILABLE TROPOSPHERIC MOISTURE
CONTENT AND SUSTAINED MODERATE EQUATORWARD UPPER-LEVEL DIVERGENCE.
THESE FAVORABLE FACTORS ARE PARTIALLY COUNTERBALANCED BY LOW TO
MODERATE (15-20 KTS) DEEP-LAYER VERTICAL WIND SHEAR (VWS). CURRENT
ANIMATED VISIBLE SATELLITE IMAGERY LOOP SHOWS PERSISTENT CENTRAL
CONVECTION ASSOCIATED WITH A FULLY OBSCURED LOW-LEVEL CIRCULATION
CENTER (LLCC) BELONGING TO TROPICAL STORM (TS) 10W (MAYSAK).
UTILIZING SURFACE WIND OBSERVATIONS COUPLED WITH ANIMATED RADAR
IMAGERY LOOPS, THE INITIAL POSITION IS ANCHORED WITH MEDIUM
CONFIDENCE. FURTHERMORE, THE INITIAL INTENSITY ESTIMATE OF 45 KTS
IS RETAINED WITH MEDIUM CONFIDENCE, SYNTHESIZED VIA AN
INTERPOLATION OF OBJECTIVE CIMSS ALGORITHMS AND SUBJECTIVE DVORAK
SATELLITE FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR)
CENTERED TO THE NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T3.0 - 45 KTS
   DEMS: T3.0 - 45 KTS
   CIMSS ADT: 47 KTS AT 040000Z
   CIMSS AIDT: 43 KTS AT 040000Z
   CIMSS D-PRINT: 38 KTS AT 040000Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

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: THROUGH THE IMMINENT SHORT-TERM MARITIME
TRANSIT, TS 10W IS ANTICIPATED TO SUSTAIN ITS CURRENT PEAK
INTENSITY OR UNDERGO MARGINAL INTENSIFICATION REACHING 50 KTS JUST
BEFORE APPROACHING THE CHINESE-VIETNAMESE BORDER. MAINTAINING A
NORTHWESTWARD TRANSLATIONAL VECTOR, TS 10W IS PROJECTED TO NAVIGATE
THE GULF OF TONKIN OVER THE SUBSEQUENT 12 HOURS. IMMEDIATELY
FOLLOWING, PROLONGED EXPOSURE TO TERRESTRIAL FRICTION AND BOUNDARY
LAYER INFLUENCES WILL INITIATE A RAPID TERMINAL DECAY PHASE. TOTAL
KINEMATIC DISSIPATION OF THE CYCLONIC VORTEX IS EXPECTED TO BE
COMPLETELY REALIZED ON OR BEFORE TAU 36, AS THE STRUCTURE
UNRAVELS OVER LAND.

MODEL DISCUSSION: DYNAMICAL INTENSITY GUIDANCE SUITES EXHIBIT GOOD
AGREEMENT CONCERNING THE NEAR-TERM MAINTENANCE OVER THE GULF OF
TONKIN AND THE SUBSEQUENT OVERLAND DEGRADATION, PRODUCING A TIGHTLY
CLUSTERED ENVELOPE SPREAD. SIMILARLY, DETERMINISTIC NUMERICAL
WEATHER PREDICTION TRACK MODELS YIELD A HIGHLY COHESIVE SPATIAL
SOLUTION WITH NEGLIGIBLE ALONG-TRACK AND CROSS-TRACK VARIANCE
PERTAINING TO THE CORE TRAJECTORY OVER THE FORECAST PERIOD. IN
LIGHT OF THIS ROBUST MULTI-MODEL CONSENSUS AND TIGHT ENVELOPE
GEOMETRY, BOTH THE OFFICIAL JOINT TYPHOON WARNING CENTER TRACK
TRAJECTORY AND INTENSITY PROFILES ARE FORMULATED AND ISSUED WITH
HIGH CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   INTENSITY 00-72 HR: HIGH//
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