WDPN32 PGTW 132100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUBTROPICAL DEPRESSION 07W (SEVEN) 
WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 31.7N 129.5E
   INITIAL INTENSITY: 25 KTS
   GEOGRAPHIC REFERENCE: 85 NM SOUTH OF SASEBO, JAPAN
   MOVEMENT PAST 6 HOURS: EAST-NORTHEASTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
THIS SYSTEM IS CLASSIFIED AS A SUBTROPICAL CYCLONE, WITH STRUCTURAL
FEATURES CHARACTERISTIC OF BOTH TROPICAL AND MID-LATITUDE CYCLONES.
THIS WARNING IS PROVIDED AS A SPECIAL ISSUANCE TO FACILITATE
RESOURCE PROTECTION. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY DEPICTS A FULLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH DEEP CONVECTION POLEWARD AND EASTWARD OF CENTER. STABLE
STRATOCUMULUS CLOUDS FLANK THE WESTERN PERIPHERY OF THE LLCC AS A
DEEP-LAYER TROUGH APPROACHES FROM THE WEST. RADAR IMAGERY REVEALS
THE CONVECTIVE BANDING WRAPPING INTO THE CIRCULATION FROM THE
SOUTHWEST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE
BASED ON THE AFOREMENTIONED ANIMATED EIR AND RADAR IMAGERY. THE
INITIAL INTENSITY OF 25 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: A NEAR EQUATORIAL RIDGE TO THE SOUTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   CIMSS SATCON: 27 KTS AT 131820Z
   CIMSS ADT: 32 KTS AT 131730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-20 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   INITIAL INTENSITY: HIGH
   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: SUBTROPICAL DEPRESSION (SD) 07W WILL CONTINUE
TO REMAIN EMBEDDED WITHIN A DEEP-LAYER TROUGH EXTENDING OVER THE
YELLOW SEA APPROACHING THE KOREAN PENINSULA. THE TROUGHING COUPLED
WITH THE NEAR EQUATORIAL RIDGE TO THE SOUTH WILL DRIVE
EAST-NORTHEASTWARD FOR THE REMAINDER OF THE FORECAST PERIOD. SD 07W
WILL MAKE LANDFALL OVER KYUSHU DURING THE NEXT 12 HOURS. THE
LOW-LEVEL CIRCULATION OF SD 07W IS ANTICIPATED TO BE FRAGMENTED
AFTER PASSING OVER THE MOUNTAINOUS TERRAIN OF KYUSHU. THROUGHOUT
THE FORECAST PERIOD, WEAKENING WILL BE GRADUAL DUE TO TOPOGRAPHIC
INTERACTION. THE SYSTEM WILL BE FULLY DISSIPATED BY TAU 24. 

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE CONTINUES TO
BIFURCATE BETWEEN TWO POTENTIAL TRACKS: ONE LEADING TO A RECURVE
SCENARIO INTO THE SEA OF JAPAN, AND THE OTHER TRACKING THE SYSTEM
EAST-NORTHEASTWARD INTO MAINLAND CHINA. WHILE THE MORE OF THE JTWC
MULTI-MODEL CONSENSUS MEMBERS (GEFS, GFS, UKMET) INDICATE A RECURVE
SCENARIO, THE JTWC FORECAST LIES CLOSELY TO NAVGEM, WHICH TRACKS
THE SYSTEM OVER KYUSHU TOWARDS SHIKOKU. THE ENSEMBLE GUIDANCE ALSO
HIGHLIGHTS THE SPLIT, BUT A LARGER NUMBER OF GEFS SOLUTIONS BRING
SD 07W ON THE SOUTHERNMOST ROUTE. THUS, THE JTWC FORECAST IS MADE
WITH LOW CONFIDENCE, BUT PERSISTENCE SHOWS THAT THE SYSTEM HAS
TRACKED CLOSELY TO THE SOUTHERLY ROUTE. THE INTENSITY GUIDANCE IS
IN GOOD AGREEMENT, BUT CONSENSUS MEMBERS WHICH TRACK THE SYSTEM
INTO THE SEA OF JAPAN, LIKE GFS AND HAFS-A, INDICATE SLIGHT
INTENSIFICATION THROUGHOUT THE FORECAST DUE TO A LACK OF
TOPOGRAPHIC INTERACTION.

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