243 
 WTPZ42 KNHC 252033
 TCDEP2
 TROPICAL STORM IGNACIO DISCUSSION NUMBER   5
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP122009
 200 PM PDT TUE AUG 25 2009
  
 VISIBLE SATELLITE PICTURES SUGGEST THAT THE CLOUD PATTERN OF IGNACIO
 HAS BECOME BETTER ORGANIZED...WITH SOME HINT OF THE BEGINNING STAGE
 OF A CENTRAL DENSE OVERCAST FORMING. EVEN THOUGH THE NORTHWEST
 SEMICIRCLE IS VOID OF DEEP CONVECTIVE CLOUDS...A WELL-DEFINED BAND
 IS OBSERVED OVER THE SOUTHEAST SEMICIRCLE.  DVORAK T-NUMBERS REMAIN
 AT T3.0 FROM BOTH TAFB AND SAB AND THE OFFICIAL INTENSITY IS
 MAINTAINED AT 45 KT.  A 1417 UTC QUIKSCAT PASS REVEALED A FEW
 UNCONTAMINATED 45-50 KT WIND VECTORS...WHICH AGREE WELL WITH THE
 CURRENT INTENSITY ESTIMATE. EVEN THOUGH THE SHEAR SHOULD REMAIN
 RELATIVELY LIGHT...THE WINDOW OF OPPORTUNITY FOR STRENGTHENING WILL
 BE CLOSING SOON SINCE THE CYCLONE SHOULD REMAIN OVER 26.5C WATERS
 FOR LESS THAN 12 HOURS.  THEREAFTER...PROGRESSIVELY COOLER WATERS
 ALONG THE FORECAST TRACK SHOULD CAUSE RAPID WEAKENING...AND IGNACIO
 IS EXPECTED TO BECOME A REMNANT LOW BY 72 HOURS.
  
 THE EARLIER QUIKSCAT PASS AND RECENT VISIBLE SATELLITE FIXES HAVE
 YIELDED FAIRLY HIGH CONFIDENCE ESTIMATES OF THE CENTER LOCATION.
 BASED UPON THOSE ESTIMATES...THE INITIAL MOTION IS 300/11.  THERE
 HAS BEEN LITTLE CHANGE TO THE OFFICIAL FORECAST TRACK.  IGNACIO
 SHOULD MAINTAIN A NORTHWESTERLY COURSE AS IT MOVES AROUND THE
 WESTERN PERIPHERY OF A DEEP-LAYER ANTICYCLONE EXTENDING FROM THE
 SOUTHERN UNITED STATES INTO THE EAST PACIFIC TO NEAR 130W.  TOWARD
 THE END OF THE PERIOD...THE CYCLONE SHOULD ASSUME A MORE WESTERLY
 TRACK ONCE IGNACIO WEAKENS AND BECOMES MORE SHALLOW.  THE OFFICIAL
 TRACK DIFFERS LITTLE FROM THE PREVIOUS ADVISORY AND LIES BETWEEN THE
 PREVIOUS FORECAST AND THE MODEL CONSENSUS.
 
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      25/2100Z 19.4N 120.3W    45 KT
  12HR VT     26/0600Z 20.4N 121.8W    50 KT
  24HR VT     26/1800Z 21.9N 123.8W    50 KT
  36HR VT     27/0600Z 23.6N 125.7W    45 KT
  48HR VT     27/1800Z 25.2N 127.6W    35 KT
  72HR VT     28/1800Z 27.0N 130.5W    25 KT...REMNANT LOW
  96HR VT     29/1800Z 27.0N 134.0W    20 KT...REMNANT LOW
 120HR VT     30/1800Z...DISSIPATED
  
 $$
 FORECASTER KIMBERLAIN
  
 

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