WTPA43 PHFO 022041

TCDCP3



TROPICAL STORM IGNACIO DISCUSSION NUMBER  36

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP122015

1100 AM HST WED SEP 02 2015



IGNACIO CONTINUES TO DO A REMARKABLE JOB OF FIGHTING OFF THE

EFFECTS OF PERSISTENT MODERATE SOUTHWESTERLY SHEAR. MICROWAVE AND

CONVENTIONAL SATELLITE IMAGERY HAVE SHOWN AN INTERMITTENT EYE-LIKE

FEATURE PERSISTING WITH IGNACIO OVER THE LAST 12 HOURS OR SO.

HOWEVER...DEEP CONVECTION IS NOT PARTICULARLY VIGOROUS AROUND THIS

FEATURE...AND THE CURRENT INTENSITY ESTIMATES RANGED FROM 3.5 FROM

SAB AND PHFO TO 4.0 FROM JTWC. CONSIDERING ALL THIS...WILL MAINTAIN

IGNACIO AT 60 KT.



IGNACIO IS CONTINUING ITS STEADY NORTHWEST MARCH TODAY. THE INITIAL

MOTION IS 305/11...WHICH IS EXPECTED TO CONTINUE FOR THE NEXT

DAY OR SO.  THIS WILL TAKE IGNACIO THROUGH A SMALL ZONE OF REDUCED

SHEAR...WHICH IS EXPECTED TO ALLOW THE CYCLONE TO MAINTAIN

INTENSITY OR ONLY VERY SLOWLY WEAKEN. A SERIES OF SHORTWAVES

ROTATING AROUND A MID-LATITUDE TROUGH TO THE NORTHWEST WILL SCOOP

IGNACIO NORTHWARD IN THE 36 TO 48 HOUR TIME FRAME. AT THAT TIME THE

SYSTEM WILL BE MOVING OVER MUCH COOLER WATER. IGNACIO WILL BE

MERGING WITH A FRONTAL BOUNDARY AND BECOMING EXTRATROPICAL OVER THE

NORTHERN PACIFIC BETWEEN 72 AND 96 HOURS AS IT ACCELERATES NORTH AND

THEN NORTHEAST INTO THE NORTHERN PACIFIC. THIS FORECAST AGREES WELL

WITH THE PREVIOUS ONE...AS WELL AS WITH THE CONSENSUS GUIDANCE

THROUGH ABOUT 72 HOURS. NOT SURPRISINGLY...THERE IS RAPIDLY

INCREASING SPREAD IN THE MODEL GUIDANCE IN THE 96-120 HOUR TIME

FRAME DUE MAINLY TO DIFFERENCES IN IGNACIO/S FORWARD SPEED.



PORTIONS OF THIS FORECAST WERE COORDINATED WITH THE OCEAN PREDICTION

CENTER IN WASHINGTON D.C.





FORECAST POSITIONS AND MAX WINDS



INIT  02/2100Z 26.7N 158.2W   60 KT  70 MPH

 12H  03/0600Z 27.7N 159.8W   60 KT  70 MPH

 24H  03/1800Z 29.0N 161.7W   60 KT  70 MPH

 36H  04/0600Z 30.8N 163.0W   55 KT  65 MPH

 48H  04/1800Z 32.9N 163.6W   55 KT  65 MPH

 72H  05/1800Z 38.2N 164.2W   50 KT  60 MPH

 96H  06/1800Z 43.4N 162.9W   45 KT  50 MPH...POST-TROP/EXTRATROP

120H  07/1800Z 48.0N 160.0W   40 KT  45 MPH...POST-TROP/EXTRATROP



$$

FORECASTER R BALLARD