WDPN32 PGTW 101500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 03W (MEGI) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 10.8N 125.0E
   INITIAL INTENSITY: 35 KTS
   GEOGRAPHIC REFERENCE: 327 NM SOUTHEAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 04 KTS

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A
RAGGED, COMPACT SYSTEM WITH FRAGMENTED RAIN BANDS AND CENTRAL
CONVECTION THAT HAVE TRACKED ONTO THE CENTRAL ISLANDS OF THE
PHILIPPINES. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE
BASED ON SEMI-CIRCULATION FEATURE IN A COMPOSITE RADAR LOOP FROM
PAGASA THAT HAS MADE LANDFALL OVER LEYTE WHICH IS SUPPORTED BY
TRIANGULATION FROM NUMEROUS ISLAND WIND OBSERVATIONS. THE INITIAL
INTENSITY OF 35KTS IS BASED ON THE HIGH END OF AGENCY AND AUTOMATED
DVORAK ESTIMATES AND IS VALIDATED BY THE SURFACE OBSERVATIONS
INCLUDING WIND AND MSLP REPORTS FROM MAASIN, SURIGAO, AND GUIUAN
ISLAND. ANALYSIS INDICATES AN UNFAVORABLE ENVIRONMENT WITH MODERATE
VWS, MODERATE POLEWARD OUTFLOW, AND WARM SST OFFSET BY FRICTIONAL
EFFECTS FROM THE RUGGED ISLAND TERRAIN. THE CYCLONE IS
QUASI-STATIONARY (QS) AS IT IS EMBEDDED IN A SHALLOW TROUGH WITH
EASTERLY TRADEWINDS TO THE NORTH AND A BELT OF WESTERLIES TO THE
SOUTH.

INITIAL WIND RADII BASIS: SURFACE OBSERVATIONS.

CURRENT STEERING MECHANISM: QUASI-STATIONARY IN A SHALLOW TROUGH
WITH EASTERLY TRADEWINDS TO THE NORTH AND A BELT OF WESTERLIES TO
THE SOUTH.   

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.0 - 30 KTS
   CIMSS ADT: 37 KTS AT 100850Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE
   VWS: 15-20 KTS
   SST: OVER LAND
   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 MEGI WILL SLOWLY TRACK AND LOOP CLOCKWISE
OVER LEYTE AND SAMAR AND BY TAU 48, WILL EXIT BACK INTO THE
PHILIPPINE SEA AS IT GETS PULLED INTO AN APPROACHING SECONDARY
CYCLONE THAT IS BIGGER AND STRONGER (TS 02W). THIS BINARY
INTERACTION WILL SUPPRESS ANY SIGNIFICANT DEVELOPMENT OF TS 03W.
THIS, IN ADDITION TO THE FRICTIONAL EFFECTS OF THE RUGGED
ISLAND TERRAIN WILL ERODE THE SYSTEM TO DISSIPATION BY TAU 36,
POSSIBLY SOONER. THE REMNANT WILL ACCELERATE EAST-NORTHEASTWARD
TOWARD TS 02W DUE TO THE BINARY INTERACTION.



MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL AGREEMENT WITH
MAINTAINING THE VORTEX OVER THE PHILIPPINE ISLANDS FOR THE NEXT
36HRS BEFORE EJECTING IT EAST-NORTHEASTWARD TOWARD TS 02W. HOWEVER,
THERE IS A WIDE SPREAD IN THE INITIAL 36-48HR TRAJECTORIES. IN VIEW
OF THIS, THERE IS LOW CONFIDENCE IN THE JTWC TRACK FORECAST. 


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