MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W (SIXTEEN) WARNING NR 02// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 16W (SIXTEEN), LOCATED APPROXIMATELY 135 NM WEST-SOUTHWEST OF ANDERSEN AFB, GUAM, HAS TRACKED SOUTHEASTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES THE LOW LEVEL CIRCULATION CENTER (LLCC) IS LOOPING TO THE SOUTHEAST AS IT TRIES TO CONSOLIDATE. A GROUPING OF RECENT MICROWAVE FIXES PROVIDES BETTER CONFIDENCE IN THE 0900Z POSITION. THE INITIAL INTENSITY IS BASED ON DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD, AND CONSISTENT WITH THE CURRENT POOR ORGANIZATION. THE SYSTEM IS CURRENTLY WITHIN A WEAKNESS IN THE LOW LEVEL SUB-TROPICAL RIDGE (STR), LEADING TO THE ERRATIC MOTION. UPPER LEVEL ANALYSIS INDICATES VERTICAL WIND SHEAR (VWS) IS LOW (05-10 KNOTS), HOWEVER, THERE IS NO WELL DEFINED OUTFLOW CHANNEL AT THIS TIME DUE TO THE PROXIMITY OF A TUTT CELL TO THE NORTH. SEA SURFACE TEMPERATURES ARE FAVORABLE. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. AS THE STR REBUILDS OVER THE NEXT 6-12 HOURS, TD 16W WILL RETURN TO A NORTHWESTWARD TRACK. THIS STEERING MECHANISM IS EXPECTED TO REMAIN IN PLACE THROUGHOUT THE FORECAST PERIOD, LEADING TO PERSISTENT NORTHWESTWARD MOTION. INTENSIFICATION IS EXPECTED TO BE SLOW IN THE SHORT TERM, AS THE CONVECTION CONTINUES TO ORGANIZE AND MOVES AWAY FROM THE NEGATIVE EFFECTS OF THE TUTT CELL, AFTER WHICH, INTENSIFICATION WILL BE NEAR THE CLIMATOLOGICAL AVERAGE. MODELS ARE GENERALLY IN GOOD AGREEMENT ON THE TRACK SOLUTION ONCE THE STEERING FLOW RE-ESTABLISHES, WITH THE GFS SERVING AS A NOTABLE OUTLIER GIVEN THAT MODEL NEVER DEVELOPS BEYOND A TROPICAL DISTURBANCE IN THE SURFACE FIELDS. C. IN THE EXTENDED PERIOD, TD 16W WILL REMAIN UNDER THE STEERING INFLUENCE OF THE STR. BEYOND TAU 72, VWS AND OUTFLOW CONDITIONS ARE EXPECTED TO IMPROVE SIGNIFICANTLY AND SSTS WILL INCREASE, LEADING TO THE POSSIBILITY OF RAPID INTENSIFICATION. DYNAMICAL AID SPREAD IS HIGHER IN THE EXTENDED TAUS. DUE TO THE INITIAL MOTION UNCERTAINTY AND LONG TERM MODEL SPREAD, THERE IS LOW CONFIDENCE IN THE JTWC WARNING TRACK.// NNNN NNNN