WDPN31 PGTW 061500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (CONSON) WARNING NR 
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 11.3N 125.9E
   INITIAL INTENSITY: 55 KTS
   GEOGRAPHIC REFERENCE: 348 NM SOUTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 11 KTS
   SIGNIFICANT WAVE HEIGHT: 25 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS THE DEEP
CONVECTION OVER THE SOUTHEAST QUADRANT OF THE CIRCULATION EXPANDING
TO THE ENTIRE EASTERN SEMICIRCLE AS THE SYSTEM MAKES LANDFALL OVER
SAMAR. THE INITIAL POSITION IS BASED ON THE PGTW POSITION FIX AND
AN EXTRAPOLATION FROM A 060855Z 37GHZ GMI IMAGE SHOWING A MICROWAVE
EYE. THE INITIAL INTENSITY OF 55 KTS IS BASED ON MULTI-AGENCY DVORAK
INTENSITY ESTIMATES.

INITIAL WIND RADII BASIS: PERSISTENCE 

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T3.0 - 45 KTS
   RJTD: T2.5 - 35 KTS
   RCTP: T3.0 - 45 KTS
   KNES: T3.5 - 55 KTS
   CIMSS ADT: 43 KTS AT 061140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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 18W IS FORECAST TO CONTINUE NORTHWESTWARD
ON ITS CURRENT TRACK, TRACKING OVER SAMAR AND THE SOUTHEAST PORTION
LUZON, EVENTUALLY CROSSING 24 NM NORTH OF MANILA SOMETIME AFTER TAU
48. THE SYSTEM THEN WILL REEMERGE OVER WATER, HEADING
WEST-NORTHWESTWARD TOWARDS HAINAN FOR THE REMAINDER OF THE
FORECAST. DESPITE THE CURRENT FAVORABLE ENVIRONMENT, TS 18W IS ONLY
EXPECTED TO REACH AN INTENSITY OF 65 KTS BY TAU 12 DUE TO LAND
INTERACTION. THE SYSTEM WILL CONTINUE TO WEAKEN OVER THE
PHILIPPINES UNTIL CROSSING INTO THE SOUTH CHINA SEA AROUND TAU 72
AT 40 KTS. AT THIS POINT, WARM SEA SURFACE TEMPERATURES AND LOW
VERTICAL WIND SHEAR WILL ALLOW TS 18W TO REACH AN INTENSITY
OF 80 KTS BY TAU 120. OF NOTE, TD 19W IS CURRENTLY 730 NM
EAST-NORTHEASTWARD OF TS 18W. THIS DISTANCE IS ON THE HIGHER
THRESHOLD OF POSSIBLE BINARY INTERACTION BETWEEN THE SYSTEMS AND
THE CURRENT FORECAST DOES NOT PREDICT ANY INTERACTION, AS THE
CURRENT FORECAST TRACKS MAINTAIN ABOUT 700 NM SEPARATION.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT IN REGARDS
TO THE TRACK FORECAST, WITH ALL MODELS SHOWING A NORTHWESTWARD
TRACK UP TO TAU 72, AND THEN A WEST-NORTHWESTWARD TRACK AFTERWARDS.
INTENSITY GUIDANCE IS IN AGREEMENT AS FAR AS THE INTENSITY TREND,
WITH ALL MODELS PREDICTING CONTINUED INTENSIFICATION, FOLLOWED BY A
WEAKENING OR STAGNANT PERIOD DUE TO LAND INTERACTION BEFORE RESUMING
STEADY INTENSIFICATION AROUND TAU 72. THE FORECAST INTENSITY IS
THEREFORE PLACED CLOSE TO THE MULTI-MODEL CONSENSUS.

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