WTPZ42 KNHC 051442 RRA

TCDEP2



HURRICANE OLIVIA DISCUSSION NUMBER  19

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP172018

800 AM PDT WED SEP 05 2018



OLIVIA IS STILL SLOWLY WEAKENING, WITH A CONTINUED EROSION OF THE

EYEWALL CONVECTION IN THE NORTHWESTERN QUADRANT.  THE VARIOUS

SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES ARE NOW IN

THE 90-100 KT RANGE, AND THE INITIAL INTENSITY IS REDUCED TO 95 KT

GIVEN THE DECAY IN THE CLOUD PATTERN SINCE THE PREVIOUS ADVISORY.



OLIVIA IS CURRENTLY EXPERIENCING MODERATE EASTERLY SHEAR, BUT THE

GUIDANCE SUGGESTS THIS SHOULD DECREASE DURING THE NEXT 12-24 H.

THEREFORE, THE MAJOR INFLUENCES ON THE INTENSITY SHOULD BE GRADUALLY

DECREASING SEA SURFACE TEMPERATURES ALONG THE FORECAST TRACK AND

ENTRAINMENT OF DRY AIR.  THE INTENSITY GUIDANCE IS IN GOOD AGREEMENT

THAT OLIVIA SHOULD WEAKEN THROUGH THE FORECAST PERIOD, AND BASED ON

THIS THE NEW INTENSITY FORECAST IS AN UPDATE OF THE PREVIOUS

FORECAST.  THERE IS A CHANCE THAT OLIVIA COULD WEAKEN FASTER THAN

CURRENTLY FORECAST DURING THE FIRST 24 H IF THE CURRENT CONVECTIVE

TREND CONTINUES.



THE INITIAL MOTION IS 280/11.  THERE IS NO CHANGE TO THE FORECAST

PHILOSOPHY FROM THE PREVIOUS ADVISORY, AND THERE ARE ONLY MINOR

ADJUSTMENTS TO THE FORECAST TRACK.  A BUILDING SUBTROPICAL RIDGE

OVER THE EASTERN PACIFIC TO THE NORTH OF OLIVIA SHOULD INDUCE A

GENERAL WEST-NORTHWESTWARD MOTION WITH INCREASING FORWARD SPEED

DURING THE NEXT SEVERAL DAYS.  TOWARD THE END OF THE FORECAST

PERIOD, GLOBAL MODELS CONTINUE TO SHOW A STRONGER RIDGE THAT WOULD

TURN OLIVIA BACK TO A WESTWARD MOTION.  THE TRACK GUIDANCE IS IN

GOOD AGREEMENT WITH THIS SCENARIO, ALTHOUGH THE UKMET AND THE UKMET