WDPN32 PGTW 060300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 28W (HALONG) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 25.6N 141.5E
   INITIAL INTENSITY: 60 KTS
   GEOGRAPHIC REFERENCE: 589 NM SOUTH OF YOKOSUKA, JAPAN
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 23 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS CONVECTIVE
BANDING WRAPPING INTO AN INCIPIENT EYE, WHICH SUPPORTS THE INITIAL
POSITION WITH HIGH CONFIDENCE. A 052358Z ASCAT-C BULLSEYE IMAGE
REVEALS A WELL-DEFINED SYMMETRIC CENTER, WITH A BAND OF 45-50 KNOT
WINDS OVER THE EASTERN QUADRANT. ANIMATED WATER VAPOR RGB IMAGERY
INDICATES IMPROVING RADIAL OUTFLOW AND A ROBUST EASTWARD OUTFLOW
CHANNEL INTO AN UPPER-LEVEL TROUGH POSITIONED TO THE NORTHEAST. THE
INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE
BASED ON THE CIMSS AIDT ESTIMATE OF 63 KNOTS, WHICH IS MORE
CONSISTENT WITH THE IMPROVED BANDING STRUCTURE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: COMPETING STEERING INFLUENCE, WITH A
BROAD SUBTROPICAL RIDGE (STR) TO THE WEST AND ANOTHER BROAD STR TO
THE EAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T2.5 - 35 KTS
   KNES: T3.5 - 55 KTS
   CIMSS ADT: 45 KTS AT 060010Z
   CIMSS AIDT: 63 KTS AT 060010Z
   CIMSS D-PRINT: 46 KTS AT 060100Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE RADIAL

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: TROPICAL STORM (TS) 28W IS LOCATED WITHIN A
COMPETING STEERING ENVIRONMENT AND IS TRACKING SLOWLY WESTWARD. TS
28W IS FORECAST TO TRACK ALONG THE WESTERN PERIPHERY OF THE EASTERN
DOMINANT STR, WITH A GRADUAL TURN TO A NORTHWESTWARD TO NORTHWARD 
TRACK BY TAU 60. TS 28W WILL UNDERGO RAPID INTENSIFICATION (RI) 
THROUGH TAU 48, WITH A PEAK INTENSITY OF 125 KNOTS OR HIGHER DUE TO 
VERY FAVORABLE ENVIRONMENTAL CONDITIONS. AFTER TAU 72, THE SYSTEM 
WILL RECURVE SHARPLY EASTWARD AND COMMENCE EXTRA-TROPICAL TRANSITION 
(ETT) BY TAU 96. EXPANSIVE GALE-FORCE WINDS ARE EXPECTED ACROSS THE 
KANTO PLAIN REGION AS THE SYSTEM TRACKS PAST NEAR TAU 84. AFTER TAU 
96, TS 28W WILL BECOME EMBEDDED IN THE MIDLATITUDE WESTERLIES, 
GAINING FRONTAL CHARACTERISTICS AND COMPLETING ETT BY TAU 120.     

MODEL DISCUSSION: WITH THE EXCEPTION OF NAVGEM, DETERMINISTIC 
GUIDANCE REMAINS IN FAIR AGREEMENT, WITH ALL MODELS DEPICTING A
SHARP RECURVATURE WELL SOUTH OF MAINLAND JAPAN. THE CROSS-TRACK
SPREAD RANGES FROM 250-340 NM NEAR THE RECURVE POINT AT TAU 48
NARROWING TO 120NM BY TAU 72. THE 051200Z EPS AND 051800Z GEFS
ENSEMBLES INDICATE GOOD AGREEMENT, WITH THE VAST MAJORITY OF
SOLUTIONS SOUTH OF THE KANTO PLAIN DUE TO THE PRESENCE OF STRONG
UPPER-LEVEL WESTERLIES OVER CENTRAL JAPAN. RELIABLE INTENSITY
GUIDANCE SUPPORTS THE RI FORECAST, WITH HAFS-A AND COAMPS-TC (GFS)
PEAKING THE INTENSITY FROM 130 TO 135 KNOTS AT TAU 72. ADDITIONALLY, 
THE 051200Z COAMPS-TC (GFS) INTENSITY ENSEMBLE INDICATES A 70-90 
PERCENT PROBABILITY OF RAPID INTENSIFICATION (RI) FROM TAU 42 TO TAU 
78.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   TRACK 72-120 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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