130 
 WTPZ42 KNHC 240232
 TCDEP2
 TROPICAL STORM ANDRES DISCUSSION NUMBER  10
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP022009
 800 PM PDT TUE JUN 23 2009
  
 SATELLITE IMAGERY INDICATES A RECENT BURST OF CONVECTION TO THE EAST
 OF THE CENTER...THOUGH THE CONVECTION REMAINS RATHER ASYMMETRIC DUE
 TO MODERATE NORTHEASTERLY SHEAR.  IN SPITE OF THE CONVECTIVE
 BURST...ANDRES HAS A RAGGED SATELLITE APPEARANCE WITH POORLY-
 DEFINED BANDING FEATURES.  FINAL DVORAK T-NUMBERS HAVE DECREASED
 OVER THE PAST 6-12 HR...AND ON THIS BASIS ANDRES IS DOWNGRADED TO A
 60 KT TROPICAL STORM.  THE EARLIER DISPARITY BETWEEN SATELLITE AND
 RECONNAISSANCE DATA SUGGESTS THAT GREATER-THAN-NORMAL UNCERTAINTY
 IS ASSOCIATED WITH THIS INTENSITY ESTIMATE.  THE OFFICIAL INTENSITY
 FORECAST CALLS FOR A GRADUAL WEAKENING OVER THE NEXT 24
 HOURS...MOSTLY A RESULT OF A PERSISTENT NORTHEASTERLY SHEAR OF 20
 TO 25 KT AND A GRADUAL DECLINE IN OCEANIC HEAT CONTENT. 
 THEREAFTER...A STEADIER AND MORE RAPID WEAKENING IS PROJECTED ONCE
 ANDRES REACHES EVEN COOLER WATERS...AND THE CYCLONE IS FORECAST TO
 BE A REMNANT LOW BY 72 HOURS.  THE INTENSITY FORECAST IS CLOSELY IN
 LINE WITH BOTH SHIPS AND ICON.
  
 ANDRES HAS RECENTLY TRACKED A LITTLE MORE TO THE LEFT...WITH AN
 INITIAL MOTION OF 305/9. SEVERAL OF THE DYNAMICAL MODELS CONTINUE
 TO INDICATE SIGNIFICANT INTERACTION BETWEEN THE CYCLONE AND THE
 NEARBY MEXICAN LANDMASS...RESULTING IN AN ABRUPT DISSIPATION.
 HOWEVER...THE GUIDANCE INDICATES MID-LEVEL RIDGING REASSERTING
 ITSELF NORTH OF THE CYCLONE AS SOON AS 12 HOURS FROM NOW...WHICH
 SHOULD CAUSE THE TRACK TO GRADUALLY BEND MORE WEST-NORTHWEST AS THE
 CENTER MOVES AWAY FROM THE MEXICAN COAST.  THE MORE LEFTWARD
 INITIAL TRACK AND THE STRENGTHENING RIDGE ARE LIKELY INDICATIONS
 THAT ANDRES SHOULD AVOID LANDFALL IN SOUTHWEST MEXICO BUT SHOULD BE
 CLOSE ENOUGH TO CAUSE POSSIBLE TROPICAL STORM CONDITIONS. BY 48
 HOURS...A WEAKER ANDRES SHOULD SLOW DOWN AND BE STEERED MORE TOWARD
 THE WEST AS A RESULT OF WEAK LOW-LEVEL RIDGING FORECAST SOUTHWEST
 OF BAJA CALIFORNIA.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      24/0300Z 19.1N 106.0W    60 KT
  12HR VT     24/1200Z 20.0N 107.0W    55 KT
  24HR VT     25/0000Z 21.0N 108.2W    50 KT
  36HR VT     25/1200Z 21.7N 109.8W    40 KT
  48HR VT     26/0000Z 22.2N 111.2W    30 KT
  72HR VT     27/0000Z 23.0N 113.5W    25 KT...REMNANT LOW
  96HR VT     28/0000Z...DISSIPATED
  
 $$
 FORECASTER KIMBERLAIN/BEVEN