WDPN31 PGTW 140300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 11W WARNING NR 05// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL DEPRESSION (TD) 11W HAS INTENSIFIED SLIGHTLY OVER THE PAST 12 HOURS AND HAS REMAINED A WEAK TD. THE SYSTEM HAS TRACKED PROGRESSIVELY NORTHWARD IN RESPONSE TO AN ADVANCING MID-LATITUDE TROUGH CURRENTLY ANALYZED OVER EASTERN ASIA. THIS TROUGH HAS ENHANCED THE LOW LEVEL GRADIENT FLOW AS IT INTERACTS WITH LOW LEVEL SUBTROPICAL RIDGING TO THE EAST, FACILITATING AN ACCELERATION TREND. POLEWARD OUTFLOW HAD MARGINALLY IMPROVED INTO A MID-LATITUDE CYCLONE, WHICH HAD HELPED IN SUSTAINING AND FUELING CONVECTION NEAR THE LLCC. HOWEVER, THIS OUTFLOW CHANNEL HAS SINCE DWINDLED AS THE 2 SYSTEMS BECAME INCREASINGLY DISPLACED FROM ONE ANOTHER. B. MORE RECENT ANIMATED INFRARED SATELLITE IMAGERY SHOWS INCREASED DEEP CONVECTION BUILDING NEAR THE CENTER, WHICH HAS BOOSTED RECENT DVORAK SATELLITE INTENSITY ESTIMATES. THOSE SATELLITE ESTIMATES FROM PGTW AND KNES REFLECT A 30 KNOT SYSTEM. CURRENT POSITION IS BASED ON RADAR FIXES FROM CHEJU ISLAND, MULTIPLE AGENCY POSITION FIXES, AND A 132327 SSMIS 37 GHZ MICROWAVE PASS. THE SYSTEM CONTINUES TO TRACK GENERALLY NORTHWARD ALONG THE WESTERN PERIPHERY OF THE LOW TO MID-LEVEL SUBTROPICAL RIDGE AXIS, APPROACHING THE MID-LATITUDE WESTERLIES AND THE BAROCLINIC ZONE. 3. FORECAST REASONING A. THERE HAVE BEEN NO SIGNIFICANT CHANGES TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROG REASONING. HOWEVER, THE FORECAST HAS BEEN SHORTENED TO 36 HOURS AND HAS BEEN SHIFTED FURTHER POLEWARD. THIS INCREASED POLEWARD TREND IS A DIRECT CONSEQUENCE OF THE PREVIOUS 12 HOUR MOTION OF THE SYSTEM AND A MORE ROBUST OBJECTIVE AID PACKAGE. B. TD 11W IS FORECAST TO TRACK NORTH TO NORTHEASTWARD TROUGHOUT THE FORECAST PERIOD AS IT CONTINUES TO ROUND THE SUBTROPICAL RIDGE AXIS AND WEAKENS. DISSIPATION IS EXPECTED AS SOON AS TAU 12 DUE TO HEIGHTENED VERTICAL WIND SHEAR AS THE JET TO THE NORTH DROPS EQUATORWARD. LAND INTERACTION WITH CHEJU ISLAND AND SOUTH KOREA WILL ONLY FURTHER WEAKEN AN ALREADY SMALL AND WEAK SYSTEM. INTRUSION OF DRY MIDLATITUDE AIR WILL ALSO AID IN WEAKENING THE SYTEM BELOW 25 KNOTS. DISSIPATION IS EXPECTED BY TAU 36 OVER SOUTHEAST KOREA. FORECAST TEAM: BRAVO// NNNN