MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 06W WARNING NR 02// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 06W (SIX), LOCATED APPROXIMATELY 212 NM EAST-SOUTHEAST OF YAP, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. THE PREVIOUS POSITION HAS BEEN ADJUSTED EASTWARD SLIGHTLY BASED ON NEWLY-AVAILABLE SATELLITE DATA. THE CURRENT POSITION IS BASED ON A RECENT PGTW SATELLITE POSITION FIX AND ANIMATED MULTISPECTRAL SATELLITE IMAGERY. THE CURRENT INTENSITY OF 25 KNOTS IS CONSISTENT WITH DVORAK SATELLITE INTENSITY ESTIMATES FROM MULTIPLE REPORTING AGENCIES. FRAGMENTED DEEP CONVECTION IS CONFINED PRIMARILY TO THE NORTHERN PORTION OF THE PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). THE LLCC LIES EQUATORWARD OF AN UPPER-LEVEL RIDGE AXIS, IN AN AREA OF LOW TO MODERATE EASTERLY VERTICAL WIND SHEAR AND FAVORABLE POLEWARD OUTFLOW. STORM MOTION HAS DECREASED IN THE PAST 12 HOURS IN RESPONSE TO A DEVELOPING WEAKNESS IN THE SUBTROPICAL STEERING RIDGE TO THE NORTH OF THE SYSTEM. 3. FORECAST REASONING. A. FORECAST TRACK SPEEDS HAVE DECREASED SINCE THE PREVIOUS WARNING IN ANTICIPATION OF A WEAKENED STEERING ENVIRONMENT DURING NEXT 48 TO 72 HOURS. MEDIUM TO EXTENDED RANGE FORECAST INTENSITIES HAVE INCREASED BASED ON FAVORABLE UPPER-LEVEL SUPPORT. B. TD 06W IS EXPECTED TO TRACK SLOWLY WEST-NORTHWESTWARD OVER THE NEXT 48 TO 72 HOURS AS IT ENCOUNTERS A WEAKNESS IN THE SUBTROPICAL RIDGE. THEREAFTER, A MID-LATITUDE TROUGH INDUCING THE WEAKNESS WILL MOVE EASTWARD, ALLOWING THE SUBTROPICAL RIDGE TO REBUILD AND STEER THE SYSTEM MORE RAPIDLY INTO THE PHILIPPINE SEA. VERTICAL WIND SHEAR SHOULD REMAIN LOW AND UPPER-LEVEL OUTFLOW IS EXPECTED TO IMPROVE, ENABLING TD 06W TO STEADILY INTENSIFY AFTER AN INITIAL PERIOD OF CONSOLIDATION DURING THE NEXT 12 HOURS. NUMERIC MODELS ARE GENERALLY IN GOOD AGREEMENT REGARDING TRACK DIRECTION BUT LESS AGREEMENT REGARDING TRACK SPEED DURING THE FIRST 72 HOURS OF THE FORECAST. GIVEN HIGH UNCERTAINTY ASSOCIATED WITH THE DEVELOPING WEAKNESS IN THE STEERING RIDGE, THE LOW-CONFIDENCE JTWC FORECAST IS PLACED NEAR THE MULTI-MODEL CONSENSUS. C. IN THE EXTENDED TAUS, TD 06W WILL TRACK STEADILY WEST- NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE REORIENTED SUBTROPICAL RIDGE. THE SYSTEM SHOULD CONTINUE TO INTENSIFY AS ENVIRONMENTAL INFLUENCES REMAIN FAVORABLE. NUMERIC MODEL GUIDANCE IS IN BETTER AGREEMENT REGARDING TRACK DIRECTION AND SPEED IN THE EXTENDED TERM, LENDING HIGHER CONFIDENCE TO THE JTWC 96 AND 120 HOUR FORECAST POSITIONS.// NNNN NNNN