WDPN31 PGTW 050900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 07W (SEVEN) 
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.5N 123.5E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 548 NM EAST-SOUTHEAST OF HONG KONG
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 21 KTS
   SIGNIFICANT WAVE HEIGHT: 14 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS FRAGMENTED
CONVECTIVE BANDING OVER THE NORTHERN SEMICIRCLE WRAPPING INTO THE
WESTERN QUADRANT OF A PARTIALLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC). A 050528Z AMSR2 89GHZ MICROWAVE IMAGE INDICATES WEAK
OVERALL STRUCTURE ALTHOUGH SHALLOW BANDING HAS IMPROVED AND NOW
WRAPS INTO A DEFINED, SMALL LLCC THUS THE INITIAL POSITION IS PLACED 
WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED 
WITH HIGH CONFIDENCE BASED ON RECENT ASCAT DATA AND THE KNES DVORAK 
ESTIMATE. THE ENVIRONMENT REMAINS FAVORABLE WITH MODERATE 
EQUATORWARD OUTFLOW, WARM SST AND LOW VERTICAL WIND SHEAR. POLEWARD 
OUTFLOW IS WEAK DUE TO A LACK OF A POLEWARD OUTFLOW MECHANISM.

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

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
ENTRENCHED TO THE NORTH AND NORTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T1.5 - 25 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD

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: TD 07W IS FORECAST TO TRACK QUICKLY
NORTHWESTWARD THROUGH THE FORECAST PERIOD ALONG THE SOUTHWESTERN
PERIPHERY OF THE STRONG STR WITH LANDFALL OVER SOUTHEAST CHINA JUST
AFTER TAU 24. TD 07W CONTINUES TO STRUGGLE GENERATING AND
MAINTAINING ORGANIZED DEEP CONVECTION DUE TO THE QUICK TRACK SPEEDS
AND WEAK NATURE OF THE LLCC. SLIGHT INTENSIFICATION IS EXPECTED BY
TAU 12 WITH A PEAK OF 35 KNOTS, HOWEVER, FAVORABLE CONDITIONS
SHOULD DEGRADE AFTER TAU 12 AS VWS INCREASES TO 25 KNOTS LEADING TO
STEADY WEAKENING AND DISSIPATION OVER LAND BY TAU 36.  

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT AT
TAU 12 WITH A 50NM SPREAD IN SOLUTIONS BUT DIVERGES BY TAU 24 WITH
A 130NM SPREAD IN SOLUTIONS SO OVERALL MEDIUM CONFIDENCE IN THE
TRACK FORECAST. THERE IS ALSO MEDIUM CONFIDENCE IN THE INTENSITY
FORECAST WITH SOME UNCERTAINTY IN THE PEAK INTENSITY NEAR TAU 12 AS
THE SYSTEM TRANSITS SOUTH OF TAIWAN. HOWEVER, THIS FORECAST IS IN
LINE WITH HWRF AND THE JTWC INTENSITY CONSENSUS GUIDANCE.  

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