654 
 WTPZ42 KNHC 250837
 TCDEP2
 TROPICAL STORM IGNACIO DISCUSSION NUMBER   3
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP122009
 200 AM PDT TUE AUG 25 2009
  
 A SERIES OF MICROWAVE IMAGES RECEIVED DURING THE PAST FEW HOURS
 INDICATE THAT THE LOW-LEVEL CENTER OF IGNACIO WAS A LITTLE BIT TO
 THE NORTH THAN PREVIOUSLY INDICATED AND REMOVED FROM THE MAIN
 CONVECTION.  HOWEVER...A NEW AREA OF DEEP CONVECTION IS CURRENTLY
 DEVELOPING NEAR THE CENTER.  THE OUTFLOW IS ESTABLISHED IN THE
 SOUTHERN SEMICIRCLE ONLY...SUGGESTING THAT THERE IS SOME NORTHERLY
 SHEAR AFFECTING THE CYCLONE. DVORAK T-NUMBER HAVE NOT CHANGED AND
 THE INITIAL INTENSITY IS KEPT AT 35 KNOTS.  IN FACT...AN ASCAT PASS
 JUST CAME IN AND SHOWS 35-KT WINDS...THE DATA HELPED TO ADJUST THE
 INITIAL WIND RADII.  IGNACIO HAS THE POTENTIAL TO GATHER SOME
 STRENGTH BEFORE IT MOVES OVER COOLER WATER IN A COUPLE OF DAYS.
 THEREAFTER... A WEAKENING IS INDICATED AND BY DAYS 4 AND 5
 IGNACIO SHOULD HAVE BECOME A REMNANT LOW.
  
 WITH THE SMALL RELOCATION OF THE CENTER...THE INITIAL MOTION IS NOW
 295 DEGREES OR WEST-NORTHWEST AT 10 KNOTS...WHICH IS NOT TOO
 DIFFERENT FROM THE PREVIOUS ADVISORY MOTION. IGNACIO IS ALREADY ON
 THE WESTERN EDGE OF THE SUBTROPICAL RIDGE WHILE A LARGE MID-LEVEL
 TROUGH IS APPROACHING THE CYCLONE FROM THE NORTHWEST. THIS PATTERN
 CALLS FOR IGNACIO TO GRADUALLY TURN MORE TO THE NORTHWEST DURING
 THE NEXT 2 TO 3 DAYS. THEREAFTER...IGNACIO SHOULD TURN TO THE WEST
 STEERED BY THE LOW-LEVEL FLOW AS IT BECOMES A SHALLOW REMNANT LOW.
 THIS IS THE SOLUTION PROVIDED BY MOST OF THE GUIDANCE AND THE
 OFFICIAL FORECAST IS IN THE MIDDLE OF THE TRACK GUIDANCE ENVELOPE.
 THE NEW FORECAST TRACK WAS ADJUSTED NORTHWARD A LITTLE BIT DUE TO
 THE SMALL RELOCATION OF THE CENTER AND NOT BECAUSE OF A CHANGE IN
 THE STEERING PATTERN.
  
  
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      25/0900Z 18.1N 118.5W    35 KT
  12HR VT     25/1800Z 18.7N 119.9W    40 KT
  24HR VT     26/0600Z 19.7N 122.0W    45 KT
  36HR VT     26/1800Z 21.0N 123.5W    50 KT
  48HR VT     27/0600Z 23.0N 125.0W    40 KT
  72HR VT     28/0600Z 26.5N 128.5W    30 KT
  96HR VT     29/0600Z 27.5N 131.5W    25 KT...REMNANT LOW
 120HR VT     30/0600Z 28.0N 135.5W    20 KT...REMNANT LOW
  
 $$
 FORECASTER AVILA
  
 

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