WDPN32 PGTW 130900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 23W (NAMTHEUN) 
WARNING NR 014//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.6N 152.6E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 123 NM SOUTHWEST OF MINAMI TORI SHIMA
   MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 10 KTS
   SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD,
PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH PERSISTENT DEEP
CONVECTION DISPLACED OVER THE NORTHEAST QUADRANT. A 130326Z AMSR2
89GHZ COLOR COMPOSITE MICROWAVE IMAGE INDICATES A WEAKLY DEFINED
LLC WITH FRAGMENTED SHALLOW BANDING AND A POORLY DEFINED CENTER.
ADDITIONALLY, THE DEEP CONVECTION IS INTENSE BUT IS NOT WELL
ORGANIZED. DUE TO THE NATURE OF THE LLC, THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE. ENVIRONMENTAL CONDITIONS REMAIN
MARGINALLY UNFAVORABLE WITH VIGOROUS SOUTHWESTERLY FLOW OVER THE
LLC OFFSET BY DIFFLUENT EASTWARD OUTFLOW. THE INITIAL INTENSITY OF
30 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AGENCY
DVORAK ESTIMATES.

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

CURRENT STEERING MECHANISM: NORTHWEST PERIPHERY OF A LOW- TO
MID-LEVEL SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTHEAST. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T2.0 - 30 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 46 KTS AT 130326Z
   CIMSS ADT: 35 KTS AT 130540Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EASTWARD

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 23W IS EXPECTED TO TRACK NORTH-NORTHEASTWARD 
TO NORTHEASTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING 
INFLUENCE OF THE STR TO THE SOUTHEAST. SLIGHT INTENSIFICATION IS 
ANTICIPATED BY TAU 12 THEN A STEADY WEAKENING TREND THROUGH THE 
REMAINDER OF THE FORECAST AS CONDITIONS GRADUALLY DEGRADE.   

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT
WITH A 110NM SPREAD IN SOLUTIONS AT TAU 48. THE TRACK GUIDANCE HAS
COME INTO BETTER AGREEMENT OVER THE PAST 12 HOURS LENDING MEDIUM
CONFIDENCE TO THE JTWC FORECAST TRACK. 

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