WTPA45 PHFO 260851

TCDCP5



TROPICAL STORM OLAF DISCUSSION NUMBER  46

NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP192015

1100 PM HST SUN OCT 25 2015



THE SATELLITE PRESENTATION OF OLAF HAS CONTINUED TO DETERIORATE

RAPIDLY THIS EVENING. DEEP CONVECTION HAS BECOME CONFINED TO THE

EAST AND NORTHEAST OF THE APPARENT LOW LEVEL CIRCULATION CENTER

/LLCC/...WHICH HAS BEEN LOCATED WITH THE ASSISTANCE OF RECENT ASCAT

AND MICROWAVE DATA. STRONG WEST-SOUTHWESTERLY VERTICAL WIND SHEAR

CONTINUES TO IMPACT OLAF...WITH SHIPS AND UW-CIMSS SHEAR MAGNITUDE

ESTIMATES CURRENTLY RUNNING 30 TO 33 KT. SUBJECTIVE DVORAK FINAL

T-NUMBERS CAME IN AT 3.5/55 KT FROM ALL THREE AGENCIES. ALTHOUGH

DVORAK CURRENT INTENSITY ESTIMATES REMAIN STRONGER DUE TO

CONSTRAINTS...RANGING FROM 4.0/65 KT TO 4.5/77 KT...BASED ON THE

RECENT ASCAT PASS AND THE POOR SATELLITE APPEARANCE OLAF WILL BE

DOWNGRADED TO A 60 KT TROPICAL STORM WITH THIS ADVISORY.



OLAF CONTINUES TO TRACK STEADILY TO THE NORTHEAST...AND THE

INITIAL MOTION ESTIMATE IS 040/10 KT. OLAF IS BEING STEERED BY AN

EAST TO WEST ORIENTED RIDGE CENTERED TO THE SOUTHEAST OF THE

CYCLONE...AND A STRONG UPPER LEVEL TROUGH TO ITS NORTHWEST. THE

UPPER LEVEL TROUGH IS BECOMING THE DOMINANT STEERING MECHANISM AND

WILL CONTINUE TO MOVE OLAF TO THE NORTHEAST WITH SOME INCREASE OF

FORWARD SPEED DURING THE NEXT COUPLE OF DAYS. AFTER ABOUT 48

HOURS...OR POSSIBLY SOONER...OLAF IS FORECAST TO BECOME COMPLETELY

DECOUPLED...WITH THE WEAKENING LOW LEVEL CENTER TURNING SHARPLY

BACK TO THE SOUTHWEST AS A STRONG LOW LEVEL RIDGE BUILDS TO THE

NORTH. THE ECMWF HAS BEEN QUITE CONSISTENT WITH THIS SCENARIO...AND

THE LATEST GFS HAS COME INTO BETTER AGREEMENT AS WELL. THE NEW

OFFICIAL FORECAST TRACK IS QUITE SIMILAR TO THE PREVIOUS TRACK...AND

IN GOOD AGREEMENT WITH THE TVCN MODEL CONSENSUS.



CONTINUED WEAKENING IS FORECAST...AS OLAF WILL BE IMPACTED BY

PERSISTENT STRONG WESTERLY WIND WIND SHEAR...AND WILL BE MOVING

OVER PROGRESSIVELY COOLER SEA SURFACE TEMPERATURES. THE NEW

INTENSITY FORECAST WEAKENS OLAF TO A TROPICAL DEPRESSION BY 48

HOURS...AND TO A REMNANT LOW BY 72 HOURS...WITH DISSIPATION EXPECTED

BY DAY 4. THIS IS IN GOOD AGREEMENT WITH THE ICON CONSENSUS...WHICH

REPRESENTS A COMPROMISE BETWEEN THE FASTER WEAKENING RATES SHOWN BY

THE STATISTICAL SHIPS AND LGEM GUIDANCE...AND THE SLOWER RATES SHOWN

BY MANY OF THE DYNAMICAL MODELS.





FORECAST POSITIONS AND MAX WINDS



INIT  26/0900Z 24.1N 142.0W   60 KT  70 MPH

 12H  26/1800Z 25.4N 140.1W   50 KT  60 MPH

 24H  27/0600Z 26.8N 137.5W   40 KT  45 MPH

 36H  27/1800Z 27.8N 135.1W   35 KT  40 MPH

 48H  28/0600Z 28.2N 133.2W   30 KT  35 MPH

 72H  29/0600Z 26.0N 134.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

 96H  30/0600Z...DISSIPATED



$$

FORECASTER JACOBSON