MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (FIVE) WARNING NR 01// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 05W (FIVE), LOCATED APPROXIMATELY 281 NM EAST OF CHUUK, HAS TRACKED WEST-NORTHWESTWARD AT 17 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION AND GOOD LOW LEVEL BANDING WRAPPING IN FROM THE NORTH. SCATTEROMETER PASSES FROM 022238Z AND 022245Z SHOW A TIGHTLY WRAPPED LLCC WITH 25 KNOT WINDS ALONG THE NORTHWESTERN PERIPHERY. UPPER LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH 5 TO 10 KNOT VERTICAL WIND SHEAR (VWS) OFFSET BY EXCELLENT DUAL CHANNEL OUTFLOW. THE INITIAL POSITION AND INITIAL INTENSITY IS BASED ON THE AFOREMENTIONED ASCAT PASS WITH GOOD CONFIDENCE. TD 05W IS TRACKING ALONG THE WESTERN PERIPHERY OF THE NEAR EQUATORIAL RIDGE (NER) TO THE EAST. 3. FORECAST REASONING. A. THIS IS THE INITIAL PROGNOSTIC REASONING AND SETS THE FORECAST PHILOSOPHY. B. TD 05W WILL CONTINUE TRACKING NORTHWESTWARD THROUGH TAU 36 UNDER THE INFLUENCE OF THE STEERING NER. IT WILL GRADUALLY INTENSIFY DUE TO THE FAVORABLE ENVIRONMENTAL CONDITIONS. THE SYSTEM WILL REDUCE SPEED AND BECOME QUASI-STATIONARY NEAR TAU 36 DUE TO A COMPETING STEERING ENVIRONMENT WITH THE NER REORIENTING TO THE SOUTHEAST AND A DEEP LAYERED SUB TROPICAL RIDGE (STR) TO THE NORTHWEST. AT THIS TIME A DEEPENING MID-LATITUDE TROUGH BETWEEN THE RIDGES WILL PROVIDE INCREASED POLEWARD OUTFLOW LEADING TO A PEAK INTENSITY OF 50 KNOTS. THE TIGHTENED GRADIENT BETWEEN THE TROUGH AND THE NER WILL ALLOW THE SYSTEM TO TRACK SHARPLY NORTHEASTWARD. AS TD 05W TRACKS NORTHEASTWARD IT WILL BEGIN TO RAPIDLY WEAKEN AS THE AFOREMENTIONED TROUGH INCREASES THE VWS ABOVE 30 KNOTS AND THE SYSTEM BEGINS TO INTERACT WITH THE STRONG WESTERLY FLOW. C. BEYOND TAU 72, TD 05W WILL CONTINUE TO TRACK NORTHEASTWARD FURTHER INTO THE MID-LATITUDE WESTERLY FLOW AND HIGHER VWS, LEADING TO ITS DISSIPATION NEAR TAU 96. AVAILABLE MODEL GUIDANCE IS IN GENERAL AGREEMENT ON THE FORECAST SCENARIO; HOWEVER, THERE IS UNCERTAINTY IN THE FORWARD SPEED AND TIMING OF THE NORTHEASTWARD SHIFT IN TRACK. DUE TO THESE FACTORS THERE IS LOW CONFIDENCE IN THE JTWC FORECAST.// NNNN NNNN