WDPN31 PGTW 230300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 14W (FOURTEEN) WARNING NR 02// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 14W, LOCATED APPROXIMATELY 350 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH-NORTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS CONVECTION ORGANIZING AND INTENSIFYING AROUND THE LOW LEVEL CIRCULATION CENTER (LLCC). A 222346Z SSMIS SERIES INDICATES THAT THE MAJORITY OF DEEP CONVECTION IS OVER THE WESTERN SEMICIRCLE, BUT THE EASTERN SEMICIRCLE SHOWS WELL ORGANIZED CLOUD LINES FEEDING INTO THE LLCC. ANIMATED WATER VAPOR IMAGERY DEPICTS A WELL-ESTABLISHED POLEWARD OUTFLOW CHANNEL BETWEEN THE UPPER LEVELS OF TD 14W AND A TUTT CELL EAST OF THE RYUKYUS, BUT THE TUTT CELL IS MOVING AWAY FROM THE SYSTEM AND IT LOOKS AS THOUGH THE CHANNEL WILL CUT OFF SOON. OUTFLOW TO THE OTHER QUADRANTS IS UNIMPEDED BUT NOTHING SPECIAL. THE 221200Z PGTW UPPER LEVEL STREAMLINE ANALYSIS SHOWS THAT TD 14W EXISTS SOUTH OF THE SUBTROPICAL RIDGE AXIS IN A HIGHLY DIFFLUENT REGION. VERTICAL WIND SHEAR IS 10 TO 15 KNOTS. SEA SURFACE TEMPERATURES ARE 31 DEGREES. THE CURRENT INTENSITY ASSESSMENT IS BASED ON DVORAK ESTIMATES FROM PGTW, KNES, AND THREE SHIP REPORTS IN THE VICINITY OF THE STORM. TD 14W IS IN A WEAK STEERING ENVIRONMENT THAT IS PART OF A DEVELOPING MONSOON GYRE. A MID-LEVEL ANTICYCLONE CENTERED NEAR 5N 140E IS PROVIDING A GENTLE POLEWARD NUDGE TO THE SYSTEM, BUT THE LACK OF A DOMINANT STEERING FORCE OVER THE PHILIPPINE SEA IS MAKING FOR GENERALLY SLOW AND ERRATIC MOVEMENT. 3. FORECAST REASONING A. THIS IS THE FIRST PROGNOSTIC REASONING BULLETIN FOR TD 14W. IT ESTABLISHES THE FORECAST PHILOSOPHY. B. RECENT GUIDANCE INDICATES TD 14W WILL INTENSIFY TO TROPICAL STORM STRENGTH DURING THE NEXT 12 HOURS, WITH SLOW POLEWARD MOVEMENT CONTINUING. THE WARM WATERS OF THE PHILIPPINE SEA AND LACK OF VERTICAL WIND SHEAR WILL ALLOW THE SYSTEM TO INTENSIFY DESPITE THE LOSS OF ITS POLEWARD OUTFLOW CHANNEL. INFLUENCE FROM THE ANTICYCLONE TO THE SOUTHEAST AND THE BETA EFFECT WILL MAKE FOR A GRADUAL TURN TO THE NORTHEAST. A DEVELOPING MONSOON GYRE PATTERN WILL MAKE FOR AN INCREASINGLY COMPLEX STEERING ENVIRONMENT AS TIME GOES ON. TD 14W WILL BEGIN DIRECT CYCLONE INTERACTION WITH A SYSTEM THAT IS CURRENTLY IN THE FORMATIVE STAGES WEST OF THE MARIANAS NEAR TAU 72. THERE IS A WIDE DISPARITY IN TRACK GUIDANCE THROUGH TAU 48, BUT SUCH DISAGREEMENT IS TO BE EXPECTED GIVEN THE INTRINSIC COMPLEXITY AND EARLY STAGE OF THE DEVELOPING GYRE. INTENSITY GUIDANCE IS COMING INTO BETTER ALIGNMENT, INDICATING A STEADY INTENSIFICATION TO JUST BELOW TYPHOON STRENGTH AT TAU 72. C. ALTHOUGH THERE IS GOOD QUALITATIVE AGREEMENT IN THE MODEL GUIDANCE REGARDING THE PENDING FORMATION OF A MONSOON GYRE OVER WESTPAC, THERE IS SIGNIFICANT UNCERTAINTY AS TO HOW THE GYRE AND ITS ASSOCIATED DIRECT CYCLONE INTERACTION WILL IMPACT TD 14W. AVAILABLE GUIDANCE INDICATES TD 14W WILL CONTINUE A NORTHEASTWARD TRACK AS PART OF A CYCLONIC ROTATION AROUND A SYSTEM TO ITS NORTHWEST THROUGH TAU 120. THE JWTC STAYS POLEWARD OF CONSENSUS IN THE EXTENDED RANGES.// NNNN