WTPZ42 KNHC 081436 RRA

TCDEP2



HURRICANE JOHN DISCUSSION NUMBER  12

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122018

900 AM MDT WED AUG 08 2018



THE SATELLITE PRESENTATION OF JOHN HAS DEGRADED OVER THE PAST 12

HOURS OR SO, WITH THE EYE NO LONGER PRESENT IN CONVENTIONAL

SATELLITE DATA.  THE CDO HAS ALSO BECOME CONSIDERABLY LESS

SYMMETRIC THAN NOTED YESTERDAY.  SATELLITE INTENSITY ESTIMATES

RANGE FROM 65 TO 77 KT, AND THE INITIAL INTENSITY HAS BEEN

LOWERED TO 75 KT FOR THIS ADVISORY.  JOHN WILL BE MOVING OVER

COOLER WATERS WITHIN THE NEXT 6-12 HOURS AND INTO A MORE STABLE

ATMOSPHERE, WHICH SHOULD CAUSE GRADUAL WEAKENING THROUGH TONIGHT.

BY THURSDAY, JOHN WILL BE MOVING OVER MUCH COLDER SSTS AND A MORE

RAPID RATE OF FILLING IS EXPECTED BY THAT TIME.  JOHN IS PREDICTED

TO BECOME A REMNANT LOW IN 2 TO 3 DAYS AS IT REACHES SSTS OF AROUND

21C.



THE HURRICANE IS MOVING NORTHWESTWARD OR 320/10 KT. JOHN SHOULD

CONTINUE MOVING NORTHWESTWARD WHILE IT REMAINS A VERTICALLY DEEP

CYCLONE, BUT ONCE IT WEAKENS AND BECOMES A MORE SHALLOW SYSTEM IT

IS EXPECTED TO TURN WEST-NORTHWESTWARD IN THE LOW-LEVEL TRADE

WIND FLOW. THE DYNAMICAL MODEL GUIDANCE REMAINS IN EXCELLENT

AGREEMENT AND LITTLE CHANGE WAS REQUIRED TO THE PREVIOUS NHC

TRACK FORECAST.



ALTHOUGH THE CENTER OF JOHN IS FORECAST TO REMAIN WELL OFFSHORE OF

THE BAJA CALIFORNIA PENINSULA, A SURGE OF MOISTURE AROUND JOHN'S

OUTER CIRCULATION IS EXPECTED TO BRING SOME LOCALLY HEAVY RAINFALL

TO PORTIONS OF BAJA CALIFORNIA SUR DURING THE NEXT COUPLE OF DAYS.

THEREFORE, INTERESTS IN THE SOUTHERN PORTION OF THE BAJA CALIFORNIA

PENINSULA SHOULD MONITOR THE PROGRESS OF JOHN.