WDPN31 PGTW 270900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 26W (BUALOI) WARNING NR 016//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.2N 113.8E
   INITIAL INTENSITY: 75 KTS
   GEOGRAPHIC REFERENCE: 321 NM EAST OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 13 KTS
   SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS PERSISTENT
CENTRAL CONVECTION ASSOCIATED WITH TYPHOON (TY) 26W (BUALOI), AS
WELL AS PULSATING RADIAL OUTFLOW BURSTS PAIRED WITH MODERATE
EQUATORWARD OUTFLOW CHANNEL. WHILE THE CONVECTION IS VIGOROUS, THE
SYSTEM STILL STRUGGLES TO ACHIEVE FULL VORTEX SYMMETRY, AS A RESULT
OF SLIGHT PRESSURE AND DRY AIR CENTERED OVER THE NORTHERN
SEMICIRCLE OF THE CIRCULATION. ADDITIONAL ENVIRONMENTAL ANALYSIS
HOWEVER, INDICATES OTHERWISE FAVORABLE ENVIRONMENT, CHARACTERIZED BY
LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS) AND WARM (28-29 C) SEA
SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS PLACED WITH
MEDIUM CONFIDENCE BASED ON TRACING OF THE CURVATURE ASSOCIATED WITH
THE CENTRAL CONVECTION CLOUD TOPS. THE INITIAL INTENSITY OF 75 KTS
IS ALSO ASSESSED WITH MEDIUM CONFIDENCE BASED ON AGENCY DVORAK
ESTIMATES OSCILLATING AROUND T4.5. THE OBJECTIVE ESTIMATES LISTED
BELOW ARE NOT FULLY REFLECTING THE STRENGTH OF THE SYSTEM, LIKELY
DUE TO ITS RELATIVELY COMPACT STRUCTURE.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.5 - 77 KTS
   RJTD: T4.0 - 65 KTS
   RCTP: T5.0 - 90 KTS
   KNES: T5.0 - 90 KTS
   DEMS: T4.5 - 77 KTS
   CIMSS SATCON: 58 KTS AT 270537Z
   CIMSS ADT: 57 KTS AT 270530Z
   CIMSS AIDT: 50 KTS AT 270530Z
   CIMSS D-MINT: 39 KTS AT 270537Z
   CIMSS D-PRINT: 63 KTS AT 270700Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 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: TY 26W IS FORECAST TO CONTINUE TRACKING
NORTHWESTWARD ALONG THE PERIPHERY OF A STR TO THE NORTHEAST. THE
ENVIRONMENT IS EXPECTED TO REMAIN FAVORABLE THROUGHOUT LANDFALL
OVER NORTHERN VIETNAM AND THE SYSTEM IS FORECAST TO REACH PEAK
INTENSITY OF APPROXIMATELY 95 KTS AROUND TAU 24. WITHIN THE NEXT 12
HOURS, NUMERICAL MODEL GUIDANCE INDICATES THAT TY 26W WILL BE ABLE
TO OVERCOME THE DRY AIR INTRUSION FROM THE NORTH, WHILE BECOMING
MORE SYMMETRICAL. AFTER THAT, PARTICULARLY CLOSER TO TAU 36,
PROXIMITY TO LAND AND ITS FRICTIONAL EFFECTS ON THE WIND FIELD WILL
RESULT IN GRADUAL WEAKENING, WHICH IS EXPECTED TO RAPIDLY
INCREASE AFTER LANDFALL.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT, WITH JGSM, THE ONLY OUTLIER, PREDICTING A TRACK CLOSER
TO HAINAN AND LANDFALL 90 NM NORTH OF THE CONSENSUS MEAN. JTWC
TRACK FORECAST IS THEREFORE LAID WITH HIGH CONFIDENCE AND CLOSE TO
THE MULTI-MODEL CONSENSUS. IN REGARD TO INTENSITY, NEARLY ALL
AVAILABLE GUIDANCE MODELS INDICATE MAXIMUM WIND SPEEDS TO INCREASE 
OVER THE NEXT 24 HOURS. MULTIPLE RAPID INTENSIFICATION (RI) AIDS ARE 
ALSO TRIGGERING AND INDICATING PEAKS OF 100-115 KTS. JTWC OFFICIAL 
FORECAST REMAINS MORE RESTRAINED AND IS PLACED CLOSE TO THE MULTI-
MODEL CONSENSUS AND WITHIN 5 KTS OF HAFS-A GUIDANCE THROUGHOUT THE 
FORECAST PERIOD.

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