WTPA43 PHFO 282104

TCDCP3



HURRICANE IGNACIO DISCUSSION NUMBER  16

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP122015

1100 AM HST FRI AUG 28 2015



IGNACIO/S CDO DEVOLVED TO A RAGGED BUT VERY SHARPLY CURVED

CONVECTIVE BAND OVER THE LAST FEW HOURS...AND A COUPLE OF SSMI/S

OVERPASSES AROUND 1620 UTC SHOWED A PARTIAL EYE FEATURE WRAPPING

NORTHWEST THROUGH SOUTHEAST AROUND THE LOW LEVEL CENTER. CURRENT

INTENSITY ESTIMATES REMAIN AT 4.5-5.0 AND THUS WE WILL MAINTAIN AN

80 KT INTENSITY FOR THIS ADVISORY.



THE HURRICANE CONTINUES TO TRACK TOWARD THE NORTHWEST OR 305

DEGREES AT ABOUT 7 KT TOWARD A WEAKNESS IN THE MID-LEVEL RIDGE...

AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT

SEVERAL DAYS. THE TRACK GUIDANCE REMAINS FAIRLY TIGHTLY CLUSTERED...

BUT THERE ARE SOME NOTEWORTHY OUTLIERS LIKE THE NAVGEM AND CANADIAN

MODELS WHICH ARE STILL WELL LEFT OF THE CONSENSUS. THE OFFICIAL

FORECAST TRACK LIES VERY CLOSE TO THE PREVIOUS FORECAST...AND IS

ALSO ON THE LEFT SIDE OF THE GUIDANCE ENVELOPE. ONE REASON FOR THIS

IS THAT MOST OF THE MODEL GUIDANCE APPEARS TO BE UNDERESTIMATING THE

EFFECT OF INCREASED WIND SHEAR WHICH IS EXPECTED TO START IMPACTING

IGNACIO AFTER 2-3 DAYS...WHICH COULD POTENTIALLY IMPART A MORE

WESTWARD MOTION AFTER 3 DAYS. WITH THIS IN MIND...IT IS VERY

IMPORTANT FOR PEOPLE NOT TO RELY TOO MUCH ON THE EXACT FORECAST

TRACK ESPECIALLY AT THE LONGER TIME RANGES.



IGNACIO IS CURRENTLY IN A WEAK SHEAR ENVIRONMENT NEAR AN UPPER

LEVEL RIDGE AXIS ALONG WITH WARM SEA SURFACE TEMPERATURES NEAR

28.5C. SEA SURFACE TEMPERATURES REMAIN OVER 28C ALONG THE FORECAST

TRACK FOR THE NEXT 3 DAYS...THEN BEGIN DROPPING SLIGHTLY. WIND SHEAR

IS EXPECTED TO REMAIN WEAK...WHICH COULD ALLOW FOR SOME ADDITIONAL

STRENGTHENING OVER THE NEXT 36-48 HOURS BEFORE INCREASING

SOUTHWEST SHEAR BEGINS TO START AFFECTING THE SYSTEM. WEAKENING

IS EXPECTED IN THE DAYS 3-5 TIME FRAME...AND OUR INTENSITY FORECAST

SHOWS A FASTER WEAKENING TREND OCCURRING THAN MOST OF THE MODEL

GUIDANCE...AND MORE IN LINE WITH THE LGEM...IN THE FACE OF THIS

MODERATE TO STRONG SHEAR.





FORECAST POSITIONS AND MAX WINDS



INIT  28/2100Z 14.6N 144.5W   80 KT  90 MPH

 12H  29/0600Z 15.1N 145.6W   80 KT  90 MPH

 24H  29/1800Z 16.1N 147.1W   85 KT 100 MPH

 36H  30/0600Z 17.0N 148.7W   90 KT 105 MPH

 48H  30/1800Z 18.0N 150.1W   90 KT 105 MPH

 72H  31/1800Z 19.8N 152.8W   80 KT  90 MPH

 96H  01/1800Z 21.8N 155.3W   70 KT  80 MPH

120H  02/1800Z 23.9N 157.7W   60 KT  70 MPH



$$

FORECASTER R BALLARD