MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W (PEIPAH) WARNING NR 17// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION 05W (PEIPAH), LOCATED APPROXIMATELY 61 NM WEST OF KOROR, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 062324Z SSMIS PASS. THE INTENSITY OF 25 KNOTS IS CONSISTENT WITH A DVORAK CURRENT INTENSITY ESTIMATE FROM PGTW AND STRUCTURE EVIDENT IN VISIBLE AND MICROWAVE SATELLITE IMAGERY. DEEP CONVECTION ASSOCIATED WITH TD 05W REMAINS CONFINED TO THE WESTERN PORTION OF THE LOW LEVEL CIRCULATION CENTER (LLCC) DUE TO STRONG EASTERLY VERTICAL WIND SHEAR. THE SYSTEM IS TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A ZONALLY-ORIENTED SUBTROPICAL RIDGE TO THE NORTH. 3. FORECAST REASONING. A. DUE TO PERSISTENT VERTICAL WIND SHEAR AND TRENDS IN STATISTICAL-DYNAMICAL INTENSITY GUIDANCE, FORECAST INTENSITIES HAVE AGAIN BEEN REDUCED FROM THE PREVIOUS WARNING. TRACK SPEEDS HAVE ALSO BEEN REDUCED FOR THE TAU 72 TO TAU 120 PERIOD CONSISTENT WITH A SLOWDOWN IN CONSENSUS TRACK GUIDANCE. B. TD 05W IS FORECAST TO TRACK WEST-NORTHWESTWARD UNDER THE CONTINUED INFLUENCE OF THE SUBTROPICAL STEERING RIDGE THROUGHOUT THE FORECAST PERIOD. THE MAJORITY OF THE NUMERICAL MODEL GUIDANCE SUPPORTS THIS SCENARIO, ALTHOUGH THE LATEST UKMET AND GFS RUNS SUGGEST THAT TD 05W MAY STALL AND TURN POLEWARD AFTER TAU 36. ECMWF ALSO INDICATES A NEAR STALL AROUND TAU 36, BUT A WESTWARD TRACK RESUMES IN LATER FORECAST TAUS. THE CURRENT FORECAST FAVORS A GENERALLY WESTWARD TRACK GIVEN ANALYSIS OF CONTINUOUS RIDGING TO THE NORTH AND THE PREPONDERANCE OF MODEL GUIDANCE IN SUPPORT OF THAT SCENARIO. TD 05W SYSTEM IS EXPECTED TO MAINTAIN INTENSITY IN THE NEAR TERM, BUT MAY INTENSIFY VERY SLIGHTLY AROUND TAU 36 DUE TO A MINIMAL RELAXATION OF VERTICAL WIND SHEAR AND IMPROVED POLEWARD OUTFLOW INDUCED BY A MIDLATITUDE TROUGH PASSING TO THE NORTH. DISSIPATION IN THE NEAR TO MEDIUM TERM IS ALSO POSSIBLE, ALTHOUGH IT APPEARS AT THIS POINT THAT SUFFICIENT UPPER LEVEL OUTFLOW AND PASSAGE OVER WARM WATER WILL ALLOW THE SYSTEM TO MAINTAIN INTENSITY AT OR ABOVE THE WARNING THRESHOLD OF 25 KNOTS. C. TD 05W IS EXPECTED TO CONTINUE WEST-NORTHWESTWARD INTO NORTHERN MINDANAO IN THE EXTENDED FORECAST PERIOD. CONSENSUS MODEL GUIDANCE IS IN GENERALLY GOOD AGREEMENT WITH THE CURRENT FORECAST TRACK, EXCEPT FOR THE AFOREMENTIONED POLEWARD TREND IN RECENT UKMET AND GFS GUIDANCE. DUE TO THIS DIVERGENCE IN THE MODEL GUIDANCE, CONFIDENCE IN THE CURRENT JTWC TRACK FORECAST IS LOW.// NNNN NNNN