000 WTPZ43 KNHC 200237 TCDEP3 TROPICAL DEPRESSION THIRTEEN-E DISCUSSION NUMBER 2 NWS NATIONAL HURRICANE CENTER MIAMI FL EP132011 700 PM PST SAT NOV 19 2011 SATELLITE IMAGERY THIS EVENING SHOWS THAT THE SHOWER ACTIVITY ASSOCIATED WITH THE DEPRESSION IS GRADUALLY BECOMING BETTER ORGANIZED...WITH A SMALL CONVECTIVE AREA NEAR THE CENTER AND AN OUTER BAND IN THE EASTERN SEMICIRCLE. SATELLITE INTENSITY ESTIMATES ARE 30 KT FROM SAB AND TAFB...AND THAT REMAINS THE INITIAL INTENSITY. THE CYCLONE CURRENTLY HAS GOOD CIRRUS OUTFLOW IN ALL DIRECTIONS EXCEPT TO THE SOUTHEAST. THE INITIAL MOTION IS 280-285 DEGREES AT ABOUT 10 KT. THE DEPRESSION REMAINS ON THE SOUTH SIDE OF A MID/UPPER-LEVEL RIDGE EXTENDING FROM THE SOUTHERN GULF OF MEXICO WEST-SOUTHWESTWARD ACROSS MEXICO. THIS RIDGE IS CURRENTLY WEAKENING SLIGHTLY AS A LARGE DEEP-LAYER TROUGH MOVES SOUTHEASTWARD INTO CALIFORNIA. THE DYNAMICAL MODELS FORECAST THIS TROUGH TO PASS NORTH OF THE DEPRESSION DURING THE NEXT 24-48 HOURS...WITH THE RIDGE BUILDING WESTWARD AS THE TROUGH MOVES AWAY. THIS EVOLUTION IS EXPECTED TO ALLOW THE DEPRESSION TO MOVE GENERALLY WEST-NORTHWESTWARD FOR 24-36 HOURS...WITH A WESTWARD TURN AFTER THAT AS THE RIDGE REBUILDS. TOWARD THE END OF THE FORECAST PERIOD...A SECOND TROUGH OVER THE NORTHEASTERN PACIFIC SHOULD AGAIN WEAKEN THE RIDGE AND ALLOW A WEST-NORTHWESTWARD MOTION TO OCCUR. THE TRACK FORECAST GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO...ALTHOUGH THE ECMWF MODEL SHOWS A MORE WESTWARD MOTION THAN THE OTHER MODELS LATE IN THE FORECAST PERIOD. THE NEW TRACK FORECAST IS CLOSE TO THE PREVIOUS TRACK AND NEAR THE CENTER OF THE GUIDANCE ENVELOPE. THE DEPRESSION IS EMBEDDED IN AN ENVIRONMENT OF LIGHT VERTICAL WIND SHEAR...AND ALL GUIDANCE FORECASTS THIS TO CONTINUE FOR THE NEXT FIVE DAYS. THUS...SEA SURFACE TEMPERATURES AND ATMOSPHERIC THERMODYNAMICS WILL BE THE MAIN FACTORS CONTROLLING THE INTENSITY. THE FIRST PART OF THE FORECAST TRACK TAKES THE CYCLONE OVER INCREASING SEA SURFACE TEMPERATURES...AND IN RESPONSE THE SHIPS...GFDL...AND HWRF MODELS FORECAST THE SYSTEM TO BECOME A HURRICANE IN 48-60 HOURS. HOWEVER...THE LGEM MODEL CALLS FOR A PEAK INTENSITY UNDER HURRICANE STRENGTH. THE NEW INTENSITY FORECAST CALLS FOR MORE STRENGTHENING THAN THE PREVIOUS FORECAST... ALTHOUGH IT IS NOT AS AGGRESSIVE AS THE SHIPS...GFDL...OR HWRF. THE CYCLONE SHOULD ENCOUNTER DECREASING SEA SURFACE TEMPERATURES BY 120 HOURS...AND THIS IS REFLECTED IN THE FORECAST WEAKENING AT THAT TIME. IF THE DEPRESSION BECOMES A TROPICAL STORM...IT WOULD BE THE LATEST-FORMING NAMED STORM IN THE EASTERN PACIFIC SINCE HURRICANE WINNIE IN 1983...WHICH FORMED ON DECEMBER 4. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 10.3N 102.1W 30 KT 35 MPH 12H 20/1200Z 10.7N 103.4W 35 KT 40 MPH 24H 21/0000Z 11.3N 105.5W 40 KT 45 MPH 36H 21/1200Z 11.7N 108.0W 50 KT 60 MPH 48H 22/0000Z 11.9N 110.4W 55 KT 65 MPH 72H 23/0000Z 12.0N 114.5W 65 KT 75 MPH 96H 24/0000Z 12.5N 119.0W 70 KT 80 MPH 120H 25/0000Z 13.5N 123.0W 55 KT 65 MPH $$ FORECASTER BEVEN