WTPZ41 KNHC 130246 RRA

TCDEP1



HURRICANE ORLENE DISCUSSION NUMBER   9

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162016

800 PM PDT MON SEP 12 2016



ORLENE'S RAPID INTENSIFICATION EPISODE HAS BEEN INTERRUPTED.

SATELLITE IMAGERY INDICATES SOME EROSION OF THE CYCLONE'S DEEP

CONVECTION, PRIMARILY OVER THE NORTHEASTERN QUADRANT OF THE

CIRCULATION. THE EYE HAS ALSO BECOME CLOUD-FILLED AND INDISTINCT.

A 2324 UTC SSM/I OVERPASS SUGGESTED THAT AN EYEWALL REPLACEMENT IS

UNDERWAY, WHICH COULD BE THE REASON FOR THE CYCLONE'S DEGRADED

SATELLITE APPEARANCE. THE LATEST SATELLITE CLASSIFICATION FROM TAFB

WAS T4.5/77KT AND THE UW-CIMSS ADT IS AROUND THAT VALUE.  A BLEND OF

THESE DATA WITH DVORAK CI-NUMBERS YIELDS AN INITIAL INTENSITY

ESTIMATE OF 90 KT.



ORLENE HAS WOBBLED A LITTLE EAST OF DUE NORTH DURING THE LAST

SEVERAL HOURS, BUT AN ESTIMATE OF THE CYCLONE'S LONGER-TERM INITIAL

MOTION ESTIMATE IS 360/05.  THE HURRICANE IS ABOUT TO ENTER A COL

REGION, WHICH SHOULD RESULT IN A NORTHWARD OR NORTH-NORTHWESTWARD

DRIFT DURING THE NEXT 24 HOURS OR SO.  THE SUBTROPICAL RIDGE IS

EXPECTED TO RE-STRENGTHEN IN ABOUT 2 DAYS, CAUSING ORLENE TO TURN

SOUTH OF DUE WEST WITH A SUBSTANTIAL INCREASE IN FORWARD SPEED. BY

120 HOURS, THE MODEL SPREAD BEGINS TO WIDEN, WITH THE ECMWF FARTHER

NORTH AND SLOWER COMPARED TO THE FASTER AND MORE SOUTHERN GFS.  THIS

DIFFERENCE ARISES DUE TO THE MODELS' HANDLING OF A STRONG MID- TO

UPPER-TROPOSPHERIC CYCLONE AROUND 140W.  THE ECMWF SHOWS THIS

FEATURE FARTHER SOUTH AND STRONGER WHILE THE GFS MAINTAINS THE

SUBTROPICAL RIDGE NORTH OF ORLENE.  THE NHC TRACK FORECAST IS NOT

MUCH DIFFERENT THAN THE PREVIOUS ONE, BUT A LITTLE SLOWER BY DAY 5=