WDPN31 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (IN-FA) WARNING NR
040//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 30.6N 121.1E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 41 NM SOUTH-SOUTHWEST OF SHANGHAI, CHINA
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: 0 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE SYSTEM
CONTINUED TO ERODE AS IT MADE LANDFALL JUST SOUTH OF SHANGHAI. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A DEFINED
LOW LEVEL CIRCULATION FEATURE IN A CMA COMPOSITE RADAR LOOP. THE
INITIAL INTENSITY OF 40KTS IS BASED ON EXTRAPOLATION FROM RECENT
AGENCY DVORAK AND AUTOMATED FIXES AND EXTRAPOLATED FROM NEARBY WIND
AND PRESSURE OBSERVATIONS AND CONSISTENT WITH THE DEGRADED METSAT
SIGNATURE.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA.

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

AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: NO CURRENT ESTIMATE
   RJTD: T3.5 - 55 KTS
   RCTP: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   CIMSS ADT: 41 KTS AT 252340Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 5-10 KTS
   SST: 26-27 CELSIUS
   OUTFLOW: STRONG POLEWARD

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TS 09W WILL CONTINUE WEST-NORTHWESTWARD INTO
THE CHINESE INTERIOR THEN RECURVE NORTHEASTWARD AFTER TAU 48 AS IT
ROUNDS THE WESTERN EDGE OF THE STR. LAND INTERACTION WILL MOSTLY BE
RESPONSIBLE FOR ITS GRADUAL DECAY DOWN TO 25KTS BY TAU 120 AS IT
REACHES THE TIP OF SHANDONG PENINSULA AND POISED TO MAKE AN EXIT
INTO THE GULF OF POHAI. THERE IS, HOWEVER, A POSSIBILITY THAT THE
SYSTEM WILL DISSIPATE OVER LAND.


MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIRLY GOOD AGREEMENT UP
TAU 72. AFTERWARD, THE MODELS WIDELY SPREAD ALONG AND ACROSS-TRACK,
LENDING MEDIUM CONFIDENCE IN THE JTWC TRACK FORECAST UP TO TAU 72
THEN LOW CONFIDENCE AFTERWARD. THERE IS LOW CONFIDENCE IN THE
INTENSITY FORECASTS DUE TO THE UNCERTAINTY IN THE TOPOGRAPHICAL
EFFECTS.

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