142 
 WTPZ42 KNHC 231632
 TCDEP2
 TROPICAL DEPRESSION SEVENTEEN-E SPECIAL DISCUSSION NUMBER   1
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP172008
 915 AM PDT THU OCT 23 2008
  
 SATELLITE IMAGERY AND RECENT MICROWAVE IMAGERY FROM SSMI AND
 QUIKSCAT INDICATE THAT THE AREA OF DISTURBED WEATHER A FEW HUNDRED
 MILES SOUTH OF MANZANILLO MEXICO HAS ACQUIRED SUFFICIENT
 ORGANIZATION TO BE CLASSIFIED AS A TROPICAL DEPRESSION. DVORAK
 CLASSIFICATIONS AT 1200 UTC FROM TAFB AND SAB SUPPORT AN INITIAL
 INTENSITY OF 30 KT. A 1324 UTC QUIKSCAT PASS SHOWING SOME RELIABLE
 20-25 KT RETRIEVALS OUTSIDE OF THE DEEP CONVECTION SOUTH AND EAST
 OF THE CENTER IS ALSO CONSISTENT WITH SLIGHTLY HIGHER WINDS IN THE
 CONVECTION. THEREFORE THE INITIAL INTENSITY IS SET TO 30 KT.
 
 A QUIKSCAT AMBIGUITY ANALYSIS...ALONG WITH A SSMI PASS FROM 1239
 UTC...SUGGESTS THAT THE BROAD SURFACE CENTER IS LOCATED SOUTHEAST
 OF THE DEEP CONVECTION DUE TO ABOUT 15-20 KT OF SOUTHEASTERLY SHEAR
 ANALYZED BY CIMSS AT THE UNIVERSITY OF WISCONSIN. THE DEPRESSION IS
 EXPECTED TO CONTINUE TO MOVE NORTHWARD FOR THE NEXT DAY OR TWO
 UNTIL IT BECOMES DECOUPLED FROM THE DEEP-LAYER FLOW AND IS STEERED
 BY THE LOW-LEVEL RIDGE...WHICH WILL INDUCE A MORE WESTWARD MOTION
 UNTIL DISSIPATION.
 
 THE DEPRESSION HAS A SHORT WINDOW IN WHICH TO INTENSIFY BEFORE A
 STRONG UPPER-LEVEL TROUGH DIGGING INTO THE REGION ON FRIDAY
 INCREASES THE VERTICAL SHEAR TO OVER 40 KNOTS. THIS WILL LIKELY
 RESULT IN THE LOW-LEVEL CENTER BECOMING DECOUPLED FROM THE DEEP
 CONVECTION. THE INTENSITY FORECAST SHOWS SLIGHT INTENSIFICATION TO
 A MINIMAL TROPICAL STORM TONIGHT...FOLLOWED BY SLOW WEAKENING AND
 DEGENERATION INTO A REMNANT LOW AFTER 72 HOURS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      23/1615Z 13.1N 104.9W    30 KT
  12HR VT     24/0000Z 13.9N 104.9W    35 KT
  24HR VT     24/1200Z 15.0N 104.9W    35 KT
  36HR VT     25/0000Z 16.3N 105.3W    30 KT
  48HR VT     25/1200Z 17.2N 106.3W    25 KT
  72HR VT     26/1200Z 17.5N 109.0W    20 KT...REMNANT LOW
  96HR VT     27/1200Z 17.5N 112.0W    20 KT...REMNANT LOW
 120HR VT     28/1200Z...DISSIPATED
  
 $$
 FORECASTER BRENNAN/BEVEN