WTPZ41 KNHC 132043 RRA

TCDEP1



HURRICANE ORLENE DISCUSSION NUMBER  12

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162016

200 PM PDT TUE SEP 13 2016



RECENT MICROWAVE SATELLITE DATA, INCLUDING AN ASCAT OVERPASS,

CONFIRM THAT ORLENE HAS BECOME TILTED WITH THE LOW-LEVEL CENTER

DISPLACED TO THE SOUTH OF THE WEAK EYE PRESENT IN VISIBLE IMAGERY.

BASED ON AN AVERAGE OF SUBJECTIVE AND OBJECTIVE SATELLITE

INTENSITY ESTIMATES, THE INITIAL INTENSITY IS REDUCED TO 75 KT.



THE MICROWAVE DATA INDICATE THAT THE CENTER OF ORLENE IS FARTHER

SOUTH THAN THE POSITION ON THE PREVIOUS ADVISORY, AND THE INITIAL

MOTION ESTIMATE IS NOW 015/2 KT. ORLENE IS NOW WITHIN A BREAK IN

THE SUBTROPICAL RIDGE CAUSED A MID- TO UPPER-LEVEL TROUGH OVER

CALIFORNIA AND THE ADJACENT WATERS.  THE DYNAMICAL MODELS FORECAST

THE TROUGH TO MOVE EASTWARD DURING THE NEXT 24-36 HOURS, WITH THE

RIDGE REBUILDING TO THE NORTH OF THE TROPICAL CYCLONE.  THIS

EVOLUTION SHOULD PRODUCE A SLOW MOTION FOR THE NEXT 12-24 HOURS,

FOLLOWED BY A TURN TOWARD THE WEST AND AN INCREASE IN FORWARD SPEED

DURING THE REMAINDER OF THE FORECAST PERIOD.  THE TRACK GUIDANCE IS

IN GOOD AGREEMENT WITH THIS SCENARIO THROUGH 96 HOURS.  AFTER THAT,

THERE REMAINS SOME SPREAD ON WHETHER ORLENE WILL TURN MORE

NORTHWARD, AS FAVORED BY THE GFS, OR CONTINUE WESTWARD AS FAVORED BY

THE ECMWF. THE NEW FORECAST TRACK IS AGAIN SIMILAR TO THE PREVIOUS

TRACK AND LIES NEAR THE CENTER OF THE CLUSTER OF THE CONSENSUS AND

DYNAMICAL MODELS.



ORLENE IS EXPERIENCING 15-20 KT OF SOUTHWESTERLY VERTICAL WIND

SHEAR, AND THIS IS LIKELY TO CONTINUE FOR ABOUT ANOTHER 24 HOURS.

AFTER THAT TIME, THE DYNAMICAL MODELS FORECAST THE SHEAR TO DECREASE=