WDPN31 PGTW 150300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING 
NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 9.3N 129.7E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 282 NM NORTH-NORTHWEST OF SONSOROL
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
DEPRESSION (TD) 01W WITH A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION
CENTER (LLCC) UNDER THE INFLUENCE OF LOW TO MODERATE (15-20 KTS)
VERTICAL WIND SHEAR DISPLACING THE DEEP CONVECTION TO THE NORTHWEST
OF THE LLCC. A TONGUE OF DRY AIR ALONG THE SOUTHEASTERN QUADRANT IS
PREVENTING DEEP CONVECTION AND HINDERING ADDITIONAL DEVELOPMENT.
THE ENVIRONMENT IS MARGINALLY FAVORABLE, CHARACTERIZED BY WARM (28-29
C) SEA SURFACE TEMPERATURES AND STRONG POLEWARD OUTFLOW. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PARTIALLY
EXPOSED LLCC. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE BASED ON THE CIMSS AUTOMATED INTENSITY ESTIMATES
AND THE ONJECTIVE AGENCY DVORAK FIXES LISTED BELOW.

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

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 33 KTS AT 142300Z
   CIMSS ADT: 33 KTS AT 150110Z
   CIMSS AIDT: 32 KTS AT 150110Z
   CIMSS D-MINT: 26 KTS AT 142130Z
   CIMSS D-PRINT: 29 KTS AT 150110Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: STRONG POLEWARD
   OTHER FACTORS: NORTHEASTERLY COLD SURGE TO THE NORTH OF THE
SYSTEM

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: AFTER A BRIEF WEST-SOUTHWESTWARD JAUNT FOR THE
LAST 6 HOURS, TD 01W HAS BEGUN TO TRACK NORTHWESTWARD ALONG THE
SOUTHWESTERN PERIPHERY OF THE STR CENTERED TO ITS NORTHEAST, 
MAINTAINING A NORTHWESTWARD TRACK FOR THE NEXT 48 HOURS. BETWEEN TAU 
48-72, 01W WILL BEGIN TO ROUND THE RIDGE AND CURVE NORTHEASTWARD 
THROUGH TAU 120. REGARDING INTENSITY, 01W IS FORECAST TO GRADUALLY 
INTENSIFY AND TEETER BETWEEN 40-45 KTS FROM AROUND TAU 36 FOR THE 
REMAINDER OF THE FORECAST. AT TAU 72, 01W WILL ENCOUNTER THE 
NORTHEASTERLY COLD SURGE, INTRODUCING DRIER AIR AND INCREASED SHEAR, 
WHICH WILL OFFSET THE FAVORABLE POLEWARD OUTFLOW AND CONTRIBUTE TO 
THE SLIGHT WEAKENING AND EVENTUAL DISSIPATION OUTSIDE THE FORECAST 
PERIOD.
 
MODEL DISCUSSION: DETERMINISTIC MODEL TRACK GUIDANCE IS IN GOOD
AGREEMENT IN A NORTHWESTWARD TRACK THROUGH TAU 72. GUIDANCE
DIVERGES WHEN 01W BEGINS TO ROUND THE RIDGE AXIS, WITH MODELS
INDICATING DIFFERENCES REGARDING TRACK SPEED AND RIDGE ORIENTATION.
AS A RESULT, THE JTWC TRACK FORECAST IS PLACED WITH MEDIUM
CONFIDENCE FROM TAU 0-72 AND IS PLACED WITH LOW CONFIDENCE FROM TAU
72-120. RELIABLE INTENSITY AIDS ARE IN MODERATE AGREEMENT; ALL
MODELS INDICATE A SLIGHT INTENSIFICATION WITH A STABLE INTENSITY
FOLLOWING, BUT MODELS DISAGREE ON THE INTENSITY. ON THE LOW END OF
THE ENVELOPE, GFS AVERAGES AROUND 30 KTS FOR THE FORECAST PERIOD.
THE MESOSCALE MODELS, HWRF, HAFS, AND COAMPS-TC, ARE ON THE
UPPER END OF THE INTENSITY ENVELOPE, HOVERING AROUND 45 KTS,
RESPECTIVELY. THE JTWC INTENSITY FORECAST IS PLACED IN CONJUNCTION
WITH THE MESOSCALE MODELS AND SLIGHTLY HIGHER THAN THE MULTI-MODEL
CONSENSUS WITH MEDIUM CONFIDENCE FROM TAU 0-72 AND LOW CONFIDENCE
FROM 72-120.

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