WDPN32 PGTW 220300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 10W (CEMPAKA) 
WARNING NR 015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 22.6N 109.1E
   INITIAL INTENSITY: 25 KTS
   GEOGRAPHIC REFERENCE: 283 NM WEST OF HONG KONG
   MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 04 KTS
   SIGNIFICANT WAVE HEIGHT: N/A

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DECREASING
CONVECTION AND ORGANIZATION OVER TD 10W. THE MAJORITY OF DEEP
CONVECTION IS FORMING ALONG THE IMMEDIATE COASTLINE DUE TO
ON-SHORE FLOW. SURFACE REPORTS AND RADAR ANIMATION INDICATE THE
VORTEX REMAINS INTACT AND HAS TURNED BACK TOWARDS THE COAST.

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

CURRENT STEERING MECHANISM: A WEAK LOW TO MID-LEVEL RIDGE OVER
EASTERN CHINA. 

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
   VWS: 5-10 KTS
   SST: OVER LAND
   OUTFLOW: MODERATE POLEWARD AND EQUATORWARD

ANALYSIS CONFIDENCE:
   INITIAL POSITION: LOW
   INITIAL INTENSITY: LOW
   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 10W MAY RE-ENTER THE GULF OF TONKIN NEAR TAU 
24. THE FORECASTING ISSUE WITH TD 10W REMAINS HOW MUCH OF THE CORE 
WILL BE LEFT WHEN AND IF IT MAKES IT TO THE COAST. ONCE OUT TO SEA 
IN THE GULF OF TONKIN, THE SYSTEM WILL RE-GENERATE IN THE VERY WARM 
30-31C WATERS AND FAVORABLE UPPER LEVEL ENVIRONMENT, BUT WILL AGAIN 
RUN INTO THE RUGGED TERRAIN OF HAINAN ISLAND. IF IT MAKES IT ACROSS 
HAINAN ISLAND, IT WILL ENCOUNTER VISCIOUS WIND SHEAR DUE TO THE NEAR 
GALE FORCE GRADIENT FLOW OVER THE SOUTH CHINA SEA UNDERNEATH 
NORTHEASTERLY UPPER LEVEL WINDS ASSOCIATED WITH OUTFLOW FROM TY 09W. 
THE SURVIVAL OF THE SYSTEM TURNS ON A NUMBER OF NUANCES SUCH AS 
EXACTLY WHERE IT ENTERS THE GULF OF TONKIN AND HOW MUCH TIME IT 
SPENDS OVER THE GULF OF TONKIN, AND HOW MUCH, IF ANY, OF THE VORTEX 
IS LEFT WHEN IT ENTERS THE SOUTH CHINA SEA. THERE IS INCREASING 
CONVICTION THAT THE SYSTEM WILL NOT SURVIVE VERY FAR BEYOND HAINAN 
ISLAND IF IT EVEN MAKES IT THAT FAR. 

MODEL DISCUSSION: GUIDANCE IS CONSISTENT IN INDICATING AN OFF-SHORE
MOVEMENT NORTHEAST OF HANOI, VIETNAM AND A CYCLONIC LOOP TOWARDS
THE WEST COAST OF HAINAN ISLAND. INTENSITY GUIDANCE INDICATES
MODERATE DEVELOPMENT TO NEAR TROPICAL STORM STRENGTH WHILE OVER THE
GULF OF TONKIN WITH A SHARP DROP IN INTENSITY AFTERWARDS.  

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