WDPN31 PGTW 010300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (KIROGI)
WARNING NR 009//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 20.4N 151.5E
   INITIAL INTENSITY: 50 KTS
   GEOGRAPHIC REFERENCE: 623 NM EAST-SOUTHEAST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 24 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS TROPICAL STORM
(TS) KIROGI (11W) EXPERIENCING A MODERATE TO HIGHLY SHEARED
ENVIRONMENT (20-25 KTS VWS) AND EXHIBITING A VERY DISORGANIZED
OVERALL STRUCTURE. THE LOW LEVEL CIRCULATION CENTER (LLCC) IS FULLY
EXPOSED TO THE SOUTHWEST OF THE STRUGGLING CONVECTIVE PLUME, WHICH
SHOWS MUCH EVIDENCE OF SHEARING ALOFT AS THE CIRRUS FRAGMENTS
PROPAGATE POLEWARD WITH THE NORTHWARD FLOW. THE INITIAL POSITION IS
PLACED WITH MEDIUM CONFIDENCE BASED ON A 010000Z HM9 PROXYVIS
SATELLITE IMAGE. THE INITIAL INTENSITY OF 50 KTS IS ASSESSED WITH
MEDIUM CONFIDENCE BASED ON MULTIAGENCY DVORAK SUBJECTIVE INTENSITY
ESTIMATES LISTED BELOW, AS WELL AS CIMSS ADT, AIDT, DPRINT OBJECTIVE
INTENSITY ESTIMATES OF 49 KTS, 54 KTS, 48 KTS, RESPECTIVELY.

INITIAL WIND RADII BASIS: PERSISTENCE 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.5 - 55 KTS
   RJTD: T3.0 - 45 KTS
   RCTP: T3.5 - 55 KTS
   CIMSS ADT: 55 KTS AT 312350Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY
UNFAVORABLE
   VWS: 20-25 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS KIROGI IS FORECAST TO CONTINUE ON A
NORTHWESTWARD TRACK THROUGH TAU 72, AND GRADUALLY SHIFT TO A
WESTWARD TRACK THROUGH TAU 120. A GRADUAL WEAKENING IS EXPECTED
THROUGH THE FORECAST PERIOD AS TS KIROGI CONTINUES TO EXPERIENCE A
HIGHLY SHEARED ENVIRONMENT WITH THE ALREADY POORLY ORGANIZED
STRUCTURE. PASSING NEARBY YAKUSHIMA ISLAND AROUND TAU 96 AT THE
TROPICAL DEPRESSION INTENSITY LOWER THRESHOLD, THE SYSTEM IS
ANTICIPATED TO ENTER THE EAST CHINA SEA AND LATER DISSIPATE PRIOR
TO TAU 120. 

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE CONTINUES TO WEAKEN TS
KIROGI THROUGH THE FORECAST PERIOD, AND TRENDS TO DISSIPATE THE
SYSTEM EARLIER OVER MULTIPLE MODEL RUNS.  MODELS REMAIN IN FAIR
AGREEMENT THROUGH TAU 72 WITH A CROSS TRACK SPREAD OF 295NM.  AFTER
TAU 72, THE GFS DETERMINISTIC TRACK CURLS COUNTERCLOCKWISE TO A
RECIPROCAL HEADING TO THE NORTHEAST AT TAU 120.  THE OPPOSING
OUTLIER, BEING NAVGEM, TRACKS THE SYSTEM AROUND THE STR TO THE
NORTH RESULTING IN A NORTHEASTWARD TRACK THROUGH TAU 120.  THE BULK
OF NUMERICAL GUIDANCE, TO INCLUDE THE MAJORITY OF ENSEMBLE MEMBERS,
TRACK THE SYSTEM WESTWARD TO DISSIPATION IN THE EAST CHINA SEA.

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
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