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 398 
 WTPA43 PHFO 020853
 TCDCP3
 
 TROPICAL STORM IGNACIO DISCUSSION NUMBER  34
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP122015
 1100 PM HST TUE SEP 01 2015
 
 DEEP CONVECTION HAS REMAINED CONFINED MAINLY TO THE NORTH AND WEST
 OF THE LOW LEVEL CIRCULATION CENTER /LLCC/ DURING THE EVENING...WITH
 JUST LAYERED CLOUDS AND LITTLE DEEP CONVECTION SOUTH OF THE LLCC.
 WHILE AN INTERMITTENT WARM SPOT NEAR THE LLCC HAS BEEN EVIDENT IN
 RECENT INFRARED SATELLITE IMAGERY...SUBJECTIVE DVORAK CURRENT
 INTENSITY ESTIMATES CAME IN AT 3.5/55KT FROM ALL THREE AGENCIES...
 AND THE INITIAL INTENSITY WILL BE HELD AT 60 KT FOR THIS ADVISORY.
 
 A SERIES OF MICROWAVE IMAGES AND THE 0600Z SUBJECTIVE CENTER
 POSITION ESTIMATES SUGGEST THAT IGNACIO SLOWED DOWN SLIGHTLY DURING
 THE LATE AFTERNOON AND EARLY EVENING...AND THE INITIAL MOTION
 ESTIMATE IS 310/09 KT. IGNACIO IS FORECAST TO CONTINUE MOVING 
 STEADILY TO THE NORTHWEST DURING THE NEXT 36 TO 48 HOURS...TOWARD A 
 WEAKNESS IN THE SUBTROPICAL RIDGE TO THE NORTH OF FRENCH FRIGATE 
 SHOALS. THERE IS NO SIGNIFICANT CHANGE TO THIS PORTION OF THE 
 FORECAST TRACK...WHICH LIES VERY CLOSE TO THE PREVIOUS TRACK AND THE 
 TVCN CONSENSUS. BEYOND 48 HOURS...IGNACIO SHOULD ACCELERATE 
 NORTHWARD AS IT BECOMES EMBEDDED IN DEEP SOUTHERLY FLOW TO THE EAST 
 OF A LONGWAVE TROUGH. THE RELIABLE TRACK GUIDANCE REMAINS IN GOOD 
 AGREEMENT DURING THIS TIME...AND THE LATEST ECMWF SHIFTED EASTWARD 
 INTO MUCH BETTER AGREEMENT WITH THE GFS/TVCN AT DAYS 4 AND 5. THE 
 NEW FORECAST TRACK HAS BEEN SHIFTED SOMEWHAT TO THE RIGHT OF THE 
 PREVIOUS TRACK FOR THOSE FORECAST TIMES...BUT STILL LIES ALONG THE 
 LEFT EDGE OF THE GUIDANCE ENVELOPE AND IS IN CLOSEST AGREEMENT WITH 
 THE ECMWF.
 
 IGNACIO CONTINUES TO FEEL THE EFFECTS OF MODERATE SOUTHWESTERLY 
 VERTICAL WIND SHEAR...WITH THE LATEST UW-CIMSS AND SHIPS ANALYSES
 INDICATING SHEAR MAGNITUDE NEAR 20 KT. THE CYCLONE MAY HAVE A WINDOW
 OF SOMEWHAT LESS HOSTILE CONDITIONS DURING THE NEXT 24 TO 36
 HOURS...WHEN SHEAR MAY LESSEN SOMEWHAT AND THE FORECAST TRACK
 WILL REMAIN OVER SEA SURFACE TEMPERATURES NEAR 27C. THE NEW
 INTENSITY FORECAST WILL MAINTAIN IGNACIO AT 60 KT DURING THIS
 TIME...IN REASONABLE AGREEMENT WITH THE LGEM AND ICON CONSENSUS...
 BUT BELOW THE SHIPS WHICH BRINGS IGNACIO BACK TO MINIMAL HURRICANE
 INTENSITY IN 24 HOURS. A SLOW WEAKENING TREND SHOULD COMMENCE BY 48
 HOURS...WHEN IGNACIO WILL BE MOVING NORTHWARD OVER COOLER WATERS.
 IGNACIO MAY BEGIN TO UNDERGO EXTRATROPICAL TRANSITION BY THE END OF
 THE FORECAST PERIOD AS IT MOVES NORTH OF 40N AND ACROSS INCREASINGLY
 COLD WATERS OF THE NORTH PACIFIC. WILL MAINTAIN IGNACIO AS A
 TROPICAL SYSTEM THROUGH 120 HOURS FOR THIS FORECAST CYCLE...IN
 COORDINATION WITH THE OCEAN PREDICTION CENTER IN WASHINGTON DC.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  02/0900Z 25.2N 156.2W   60 KT  70 MPH
  12H  02/1800Z 25.9N 157.4W   60 KT  70 MPH
  24H  03/0600Z 27.2N 159.6W   60 KT  70 MPH
  36H  03/1800Z 28.4N 161.6W   60 KT  70 MPH
  48H  04/0600Z 29.7N 163.0W   55 KT  65 MPH
  72H  05/0600Z 33.6N 164.2W   50 KT  60 MPH
  96H  06/0600Z 38.5N 165.0W   50 KT  60 MPH
 120H  07/0600Z 44.0N 163.5W   50 KT  60 MPH
  
 $$
 FORECASTER JACOBSON
  
 
 
 
 
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