907 
 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