WDPN31 PGTW 210900 COR
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 03W (THREE) 
CORRECTED/WARNING NR 01//
RMKS//
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   TROPICAL DEPRESSION (TD) 03W, LOCATED APPROXIMATELY 160 NM SOUTH-
SOUTHEAST OF ANDERSEN AFB, GUAM, HAS TRACKED WESTWARD AT 06 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL (MSI) SATELLITE 
IMAGERY CONTINUES TO SHOW AN OVERALL IMPROVEMENT IN THE 
CONSOLIDATION OF CONVECTION SURROUNDING THE LOW-LEVEL CIRCULATION 
CENTER (LLCC). A 210221Z OSCAT PASS INDICATES A LOW-LEVEL 
CIRCULATION CENTER (LLCC) LOCATED DUE SOUTH OF GUAM. RECENT RADAR 
REFLECTIVITIES FROM GUAM INDICATE SHARP TURNING WITHIN A STRONG 
CONVECTIVE CLUSTER LOCATED NEAR THE OSCAT CIRCULATION. HOWEVER, THE 
MSI AND RECENT MICROWAVE DATA DO NOT SUPPORT A LLCC IN THIS 
LOCATION. CONSIDERING THE PAST HISTORY OF THIS MONSOON DEPRESSION 
LIKE SYSTEM, AND ASSOCIATED MESOVORTICES ROTATING CYCLONICALLY 
AROUND THE CENTER OF MASS, IT IS BELIEVED THAT THE CIRCULATION SOUTH 
OF GUAM IS NOT THE TRUE LLCC. THE MSI AND MICROWAVE DATA PROVIDE FOR 
A MORE TIME TESTED ANALYSIS TOOL THAN THE EXPERIMENTAL OSCAT 
PRODUCT. THEREFORE, THE CURRENT POSITION IS BASED ON THE MSI AND 
MICROWAVE DATA BUT THE CONFIDENCE REMAINS LOW DUE TO THE CONFLICTING 
OSCAT PASS. THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES 
RANGING FROM 25-30 KNOTS FROM RJTD/KNES AND PGTW RESPECTIVELY. THE 
WIND FIELD FOR TD 03W, AS SEEN IN PAST SCATTEROMETER DATA, HAS BEEN 
CONSISTENT WITH A MONSOON DEPRESSION IN THAT CENTRAL WINDS ARE 
LIGHTER AND PERIPHERAL WINDS ARE STRONGER, ESPECIALLY ON THE 
NORTHEASTERN QUADRANT. TD 03W IS TRACKING ALONG THE SOUTHWESTERN 
PERIPHERY OF THE SUBTROPICAL RIDGE (STR) CENTERED FAR TO THE 
NORTHEAST. THE UPPER-LEVEL ENVIRONMENT HAS IMPROVED DURING THE PAST 
24 HOURS, AS EVIDENT IN THE PGTW 210000Z UPPER-LEVEL STREAMLINE 
ANALYSIS AND ANIMATED WATER VAPOR IMAGERY. THE TROPICAL UPPER 
TROPOSPHERIC TROUGH (TUTT) CELL LOCATED SOUTHWEST OF GUAM HAS 
CONTINUED TO MIGRATE WESTWARD AND THE DIVERGENT SIDE OF THE TUTT 
CELL IS NOW ENHANCING THE POLEWARD OUTFLOW OF THE DISTURBANCE. 
ADDITIONALLY, AN IMPROVEMENT IN EQUATORWARD OUTFLOW HAS OCCURRED 
WITH THE DEVELOPMENT OF A POINT SOURCE OF DIFFLUENCE LOCATED JUST TO 
THE EAST OF THE LLCC. OUTFLOW TO THE EAST INTO A TUTT CELL NEAR THE 
DATELINE ALSO REMAINS ROBUST.
3. FORECAST REASONING.
   A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE 
FORECAST PHILOSOPHY.
   B. THE ORIENTATION OF THE STR IS EXPECTED TO BREAK DOWN AND 
RETROGRADE TO THE EAST AS AN APPROACHING MID-LATITUDE TROUGH, 
EXTENDING FROM CYCLOGENISIS CURRENTLY DEVELOPING OVER SOUTHERN 
JAPAN, INTERACTS WITH THE RIDGING. TD 03W SHOULD PASS JUST SOUTH OF 
GUAM DURING THE NEXT 12-18 HOURS AND THEN TRACK GENERALLY 
NORTHWESTWARDS AROUND THE ERODING STR PERIPHERY. BY TAU 48 THE 
SYSTEM SHOULD BEGIN TO ROUND THE STR AND BEGIN A MORE POLEWARD 
TRACK WHICH WILL STEER TOWARDS A RE-CURVATURE INTO THE MID-
LATITUDES. INTENSITY DURING THIS TIME SHOULD GRADUALLY INCREASE AS 
THE UPPER-LEVEL ENVIRONMENT REMAINS FAVORABLE.
   C. AFTER TAU 72, TD 03W IS FORECAST TO MOVE NORTH OF THE STR AND 
BEGIN TO INTERACT WITH THE MID-LATITUDE BAROCLINIC ZONE. EXTRA-
TROPICAL TRANSITION (ET) SHOULD BEGIN DURING TAU 96 WITH COMPLETION 
INTO THE WESTERLIES BY TAU 120. DURING THIS TIME INTENSITY WILL 
BEGIN TO DECREASE DUE TO AN INCREASE IN VERTICAL WINDSHEAR. MOST 
MODELS ARE IN AGREEMENT WITH SHOWING THE SYSTEM FULLY INCORPORATED 
IN THE MID-LATITUDE WESTERLIES BY TAU 120. THERE IS LOW CONFIDENCE 
IN THE FORECAST TRACK BASED ON THE POOR INITIAL POSITION 
CONFIDENCE. HOWEVER, THERE IS A LOW DEGREE OF SPREAD WITHIN THE 
OBJECTIVE AIDS DURING THE FIRST 48 HOURS.
4.JUSTIFICATION FOR CORRECTION: CHANGED 6 HOUR SUMMARY TO 12 HOUR 
SUMMARY IN PARA 2 HEADER. ADDED GEOGRAPHIC REFERENCE AND PAST 6 HOUR 
MOTION IN PARA 2 BODY.//
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