WDPN31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 27W (MATMO) WARNING NR 018//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.4N 109.5E
   INITIAL INTENSITY: 80 KTS
   GEOGRAPHIC REFERENCE: 203 NM EAST OF HANOI, VIETNAM
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 20 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
27W (MATMO) WITH A CLOUD-FILLED EYE JUST OFF THE COAST OF SOUTHERN
CHINA IN THE GULF OF TONKIN. THE CORE OF THE SYSTEM HAS TAKEN A HIT
AFTER TRAVERSING OVER THE LEIZHOU PENINSULA AROUND 050900Z, NOW
WITH A VERY RAGGED EYEWALL. A 051005Z WSFM 89 GHZ MICROWAVE IMAGE
REVEALED LARGE MICROWAVE EYE FEATURE JUST WEST OF THE PENINSULA
WITH COLD CLOUD TOPS STILL ENIRELY SURROUNDING THE CENTER. THE
INITAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON ANIMATED
RADAR IMAGERY AND THE WSFM MICROWAVE IMAGE. THE INITIAL INTENSITY
OF 80 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY
DVORAK FIXES AND CIMSS OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE CENTERED TO THE NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T5.0 - 90 KTS
   RJTD: T4.5 - 77 KTS
   KNES: T5.0 - 90 KTS
   DEMS: T5.0 - 90 KTS
   CIMSS ADT: 90 KTS AT 051200Z
   CIMSS AIDT: 83 KTS AT 051200Z
   CIMSS D-MINT: 88 KTS AT 050823Z
   CIMSS D-PRINT: 80 KTS AT 051200Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 10-15 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE RADIAL
   OTHER FACTORS: TERRAIN INTERACTION

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: 27W IS FORECAST TO TRACK WEST-NORTHWESTWARD,
ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE
THROUGHOUT THE FORECAST PERIOD. A FINAL LANDFALL, JUST EAST OF THE
VIETNAM-CHINA BORDER IS EXPECTED WITHIN THE NEXT 6 HOURS. 27W IS
FORECAST TO WEAKEN THROUGHOUT THE FORECAST PERIOD AS INCREASING
TERRAIN INTERACTION CONTINUES TO DETERIORATE THE VORTEX. A COMPLETE
DISSIPATION IS EXPECTED TO OCCUR NEAR TAU 36, NORTH OF VIETNAM.


MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN VERY GOOD
AGREEMENT WITH A 73 NM CROSS-TRACK SPREAD AT TAU 36. THE JTWC TRACK
FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH HIGH
CONFIDENCE. INTENSITY GUIDANCE IS IN GOOD AGREEMENT ON WEAKENING
THROUGHOUT THE FORECAST PERIOD, SUPPORTING THE JTWC INTENSITY
FORECAST WITH MEDIUM CONFIDENCE.

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