MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 21W (DUJUAN) WARNING NR 05// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 21W (DUJUAN), LOCATED APPROXIMATELY 469 NM SOUTH-SOUTHWEST OF IWO TO, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED IR (EIR) SATELLITE IMAGERY DEPICTS PERSISTENT CONVECTION THAT IS ASYMMETRIC, WITH A CLEAR LOW LEVEL CIRCULATION TO THE EAST OF THE DEEP CONVECTION. A 211735Z SSMI IMAGE SHOWS VERY FRAGMENTED BANDING WITH THE DEEP CONVECTION ON THE WESTERN SIDE OF THE SYSTEM. THE INITIAL POSITION IS BASED ON THE PARTIAL LLCC IN THE AFOREMENTIONED MICROWAVE IMAGE AND THE EIR LOOP WITH LOW CONFIDENCE. THE CURRENT INTENSITY HAS BEEN MAINTAINED AT 30 KNOTS BASED ON THE PREVIOUS ASCAT PASS, SLIGHTLY HIGHER THAN THE DT1.5 REPORTED FROM KNES, RJTD AND PGTW. ENVIRONMENTAL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH 20 TO 25 KNOTS OF EASTERLY VWS BEING PARTIALLY OFFSET BY DIVERGENCE ALOFT AND HIGH SSTS. TD 21W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP LAYERED STR. 3. FORECAST REASONING. A. THERE IS A SLIGHT CHANGE IN THE JTWC FORECAST PHILOSOPHY WITH A MORE FLAT TRACK IN THE NEAR TERM AND RECURVING AROUND THE STR BEYOND TAU 36. B. TD DUJUAN WILL CONTINUE TO TRACK WEST-NORTHWESTWARD OVER THE NEXT 36 HOURS AS THE STR REMAINS TO THE NORTH OF THE SYSTEM. DURING THIS TIMEFRAME, EXPECT MARGINAL INTENSIFICATION DUE TO MODERATE VWS AFFECTING THE SYSTEM. BEYOND TAU 36, EXPECT A SHORTWAVE MID-LATITUDE TROUGH TO CREATE A SMALL BREAK IN THE STR, ALLOWING A STRONGER TD 21W TO GAIN A MORE POLEWARD TRAJECTORY. ADDITIONALLY, EXPECT IMPROVED OUTFLOW TO ALLOW FOR NEAR RAPID INTENSIFICATION FOR THE SYSTEM THROUGH TAU 72. C. IN THE EXTENDED FORECAST, TD 21W WILL CONTINUE TO INTENSIFY DUE TO FAVORABLE ENVIRONMENTAL CONDITIONS. HOWEVER, DUE TO LOWER SSTS AND OCEAN HEAT CONTENT, TD DUJAUN'S INTENSIFICATION WILL BE AT A SLOWER RATE. DYNAMIC MODEL GUIDANCE CONTINUES TO DISPLAY A WIDE SPREAD OF SOLUTIONS REGARDING THE TIMING AND EXTENT OF THE RECURVE, WITH GFS NOW DEPICTING A MORE FLAT TRACK, COMING INTO BETTER ALIGNMENT WITH THE NAVGEM SUITE. THE JTWC TRACK HAS FLATTENED SIGNIFICANTLY IN THE EARLY STAGES OF THE FORECAST TO TAKE INTO CONSIDERATION HOW SLOWLY THE SYSTEM HAS CONSOLIDATED, NOT ALLOWING THE SYSTEM TO TRACK INTO THE STR. DUE TO THE CONTINUED WIDE SPREAD IN DYNAMIC MODEL GUIDANCE, THERE REMAINS LOW CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN