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 WTPZ43 KNHC 151448
 TCDEP3
 HURRICANE JAVIER DISCUSSION NUMBER  20
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 8 AM PDT WED SEP 15 2004
 
 A TROPICAL STORM WATCH WILL LIKELY BE REQUIRED THIS AFTERNOON FOR A
 PORTION OF THE BAJA CALIFORNIA COAST.
  
 AN EARLIER 15/0503Z TRMM PASS DEPICTED A SMALL ROUND EYE WITH A
 STRONG BANDING FEATURE OVER THE WESTERN PORTION OF THE TROPICAL
 CYCLONE. LAST NIGHT'S IMAGERY REVEALED A COLLAPSE OF THE EYE WALL
 OVER THE NORTH QUADRANT...SUGGESTING AN EYE WALL REPLACEMENT CYCLE
 HAS TAKEN PLACE. THE DVORAK CURRENT INTENSITY ESTIMATES ARE DOWN TO
 115 KT FROM TAFB AND SAB...125 KT FROM AFWA. THE INITIAL INTENSITY
 IS DECREASED ONLY TO 120 KT JUST IN CASE JAVIER MAY UNDERGO ANOTHER
 EYE WALL REPLACEMENT CYCLE. SATELLITE ANIMATION OVER THE PAST 12
 HOURS DEPICTS A HINT OF EASTERLY SHEAR HAMPERING THE OUTFLOW OVER
 THE EAST QUADRANT. HOWEVER...THE SHEAR IS NOT NEARLY STRONG ENOUGH
 TO SIGNIFICANTLY WEAKEN THE TROPICAL CYCLONE. 200 MB SYNOPTIC
 ANALYSIS SUGGESTS AN UPPER HIGH OVER MEXICO...BETWEEN IVAN AND
 JAVIER. ONCE IVAN MOVES INLAND...OUTFLOW COULD IMPROVE DRAMATICALLY
 OVER JAVIER. BUT AT THE MOMENT...NEITHER SHIPS NOR THE GFDL
 INDICATES THIS SCENARIO. THEREFORE...THE INTENSITY FORECAST CALLS
 FOR A GRADUAL WEAKENING THROUGH 72 HOURS...SIMILAR TO THE PREVIOUS
 FORECAST...THEN A RAPID DECREASE AS JAVIER MOVES OVER SIGNIFICANTLY
 COOLER SEA SURFACE TEMPERATURES. THERE STILL MAY BE FLUCTUATIONS IN
 INTENSITY IF EYEWALL REPLACEMENT CYCLES CONTINUE.
  
 INITIAL MOTION IS 325/6...WITH AN EXPECTED GRADUAL INCREASE IN
 FORWARD MOTION. THE GLOBAL MODELS AND THE GFDL ALL AGREE WITH A
 BUILDING RIDGE OVER CENTRAL MEXICO IN 36 HOURS AS IVAN MOVES
 INLAND. THIS SHOULD STEER JAVIER IN A NORTHWESTWARD MOTION THROUGH
 72 HOURS. AFTERWARD...A REDUCTION IN SPEED AND A TURN TO THE NORTH
 IS FORECAST IN RESPONSE TO AN APPROACHING MID-LATITUDE TROUGH
 TOWARD THE CALIFORNIA COAST. THE OFFICIAL FORECAST IS BASED ON THE
 GUNS CONSENSUS...WHICH EXCLUDES THE WEAK TROPICAL CYCLONE
 INITIALIZATION OF THE GFS...AND FOLLOWS CLOSELY TO THE PREVIOUS
 PACKAGE.
  
 FORECASTER ROBERTS/BEVEN
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      15/1500Z 18.3N 108.7W   120 KT
  12HR VT     16/0000Z 19.1N 109.3W   115 KT
  24HR VT     16/1200Z 20.3N 110.0W   105 KT
  36HR VT     17/0000Z 21.5N 111.0W    95 KT
  48HR VT     17/1200Z 22.6N 112.1W    85 KT
  72HR VT     18/1200Z 25.0N 114.5W    75 KT
  96HR VT     19/1200Z 26.5N 115.5W    50 KT
 120HR VT     20/1200Z 27.5N 115.5W    30 KT
  
  
 $$