WDPN31 PGTW 190300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W (SIXTEEN) 
WARNING NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 17.3N 108.1E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 79 NM NORTH OF DA NANG, VIETNAM
   MOVEMENT PAST 6 HOURS: WESTWARD AT 17 KTS
   SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD AND
DISORGANIZED LOW-LEVEL CIRCULATION OBSCURED BY FLARING CONVECTION.
TD 16W IS MOVING TOWARDS THE NORTHERN COAST OF VIETNAM,
ENCOUNTERING MARGINALLY FAVORABLE, YET STEADILY DEGRADING
ENVIRONMENTAL CONDITIONS. AFTER A BRIEF PERIOD OF MINOR
CONSOLIDATION, THE OUTFLOW IS GENERALLY RESTRICTED TOWARDS THE
REGION SOUTH-WEST OF THE SYSTEM. THE INITIAL POSITION IS PLACED
WITH MEDIUM CONFIDENCE BASED ON VISIBLE, ANIMATED EIR IMAGERY, AS
WELL AS PGTW RADAR FIX. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED
WITH MEDIUM CONFIDENCE BASED ON THE AGENCY AND OBJECTIVE FIXES
LISTED BELOW.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTH

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T1.5 - 25 KTS
   CIMSS ADT: 35 KTS AT 190010Z

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: NOT APPLICABLE

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TD 16W SPEED OVER WATER INCREASED TO 17 KTS
SINCE THE LAST FORECAST AND THE SYSTEM IS HEADING TOWARDS NORTHERN
VIETNAM AND IS EXPECTED TO MAKE LANDFALL APPROXIMATELY 90 NM
NORTHWEST OF DA NANG, WHILE MAINTAINING ITS CURRENT INTENSITY OF
30 KTS. SINCE THEN, DUE TO TERRAIN INTERACTION, TD 16W IS FORECAST
TO BEGIN STEADY WEAKENING DOWN TO 20 KTS INTENSITY BY TAU 36. WHILE
THE SEA SURFACE TEMPERATURES ARE LOWERING, THE 29-30 DEGREES
CELSIUS ARE STILL FAVORABLE. VERTICAL WIND SHEAR HOWEVER IS ON THE
HIGHER END OF THE 15-20 KTS THRESHOLD, HINDERING ANY FURTHER
DEVELOPMENT.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN FAIR
AGREEMENT IN REGARDS TO BOTH TRACK AND SPEED, UNTIL THE FORECASTED
DISSIPATION BY TAU 36, WITH ONE CAVEAT - MOST RECENT GUIDANCE
SHIFTED THE LANDFALL LOCATION SLIGHTLY SOUTH, CLOSER TO DA NANG.
JTWC FORECAST REFLECTS THAT CHANGE AND IS IN CLOSE PROXIMITY TO THE
MULTI-MODEL CONSENSUS ESTIMATE. INTENSITY TRACKERS ARE IN GOOD
AGREEMENT, ALL INDICATING DISSIPATION BY TAU 36.

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