WDPN33 PGTW 080300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 19W (PARMA)// WARNING NR 42// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. RECENT ANIMATED MULTISPECTRAL IMAGERY SHOWS THAT TD PARMA HAS MOVED BACK OVER NORTHERN LUZON AND IS SLOWLY ACCELERATING TO THE WEST. THE SYSTEM IS STILL MAINTAINING SPORADIC POCKETS OF DEEP CONVECTION, BUT HAS BECOME LARGELY UNORGANIZED NEAR THE LOW LEVEL CIRCULATION CENTER (LLCC). SOME ORGANIZED BANDING IS SEEN TO THE SOUTHWEST OF THE LLCC, BUT IT IS BEING DISRUPTED BY TOPOGRAPHY BEFORE IT WRAPS INTO THE CENTER. THE SYSTEM IS ALSO STILL EXHIBITING GOOD OUTFLOW TO THE SOUTHWEST. PARMA REMAINS IN A RELATIVELY WEAK STEERING ENVIRONMENT, BUT IS COMING MORE UNDER THE INFLUENCE OF THE SUBTROPICAL RIDGE (STR) OVER SOUTHERN CHINA AS TS 20W (MELOR) ACCELERATES TO THE NORTHWEST. THE CURRENT POSITION IS BASED ON POSITION FIXES BY PGTW AND THE CURRENT INTENSITY IS BASED WITH LOW CONFIDENCE ON OBSERVATIONS IN THE AREA AND A 072222Z QUIKSCAT PASS. 3. FORECAST REASONING A. THE FORECAST REASONING HAS NOT SIGNIFICANTLY CHANGED SINCE THE LAST PROGNOSTIC REASONING BULLETIN. B. TD PARMA WILL CONTINUE TO DRIFT GENERALLY WESTWARD IN A VERY WEAK STEERING ENVIRONMENT OVER THE NEXT 48 HOURS. PARMA IS ALSO EXPECTED TO WEAKEN AS IT TRACKS BACK OVER NORTHERN LUZON BEFORE MOVING BACK OVER WATER AFTER TAU 24. C. BEYOND TAU 48, TD PARMA WILL CONTINUE TRACKING WESTWARD UNDER THE INFLUENCE OF THE STR ANCHORED OVER CHINA, WHICH IS FORECAST TO GRADUALLY BUILD EASTWARD. AS THE STEERING INFLUENCE BECOMES MORE DEFINED BY TAU 72, PARMA WILL START TO PICK UP TRACK SPEED THROUGH THE SOUTH CHINA SEA AND GRADUALLY RE-INTENSIFY UNDER FAVORABLE ENVIRONMENTAL CONDITIONS CHARACTERIZED BY GOOD EQUATORWARD OUTFLOW SOUTH OF THE SUBTROPICAL RIDGE AXIS, MODERATE AMOUNTS OF VERTICAL WIND SHEAR AND WARM WATERS. THE NUMERICAL MODEL AIDS GENERALLY AGREE WITH A SLOW TRACK TO THE WEST WITH EVENTUAL ACCELERATION, THOUGH THE EVENTUAL TRACK SPEED AND TRAJECTORY ARE VARIED. NOGAPS AND GFS ARE BOTH SLOW AND ARE THE NORTHERN AND SOUTHERN OUTLIERS RESPECTIVELY. JGSM IS WESTWARD, BUT MUCH SLOWER THAN OTHER AIDS. UKMO, ECMWF AND GFDN TRACK THE SYSTEM FASTER AND JUST NORTH OF WEST. THIS FORECAST LEANS ON THE LATTER SOLUTIONS PROVIDED BY GFDN, UKMO AND ECMWF.// NNNN