WTPZ41 KNHC 011454 RRA

TCDEP1



HURRICANE NORMAN DISCUSSION NUMBER  18

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP162018

800 AM PDT SAT SEP 01 2018



ALTHOUGH SATELLITE INTENSITY ESTIMATES INDICATE THAT NORMAN HAS

CONTINUED TO WEAKEN, THE WEAKENING TREND APPEARS TO HAVE ABATED.

THIS IS BASED ON RECENT INFRARED IMAGERY SHOWING A BETTER DEVELOPED

CDO FEATURE ACCOMPANIED BY IMPROVED OUTFLOW, AND ALSO A WELL-DEFINED

CLOSED EYE NOW DEPICTED IN A 1148Z AMSR AND 1158Z SSMIS MICROWAVE

SATELLITE IMAGES. THE INITIAL INTENSITY HAS BEEN LOWERED TO 90 KT,

WHICH IS A BLEND OF THE VARIOUS SATELLITE INTENSITY ESTIMATES, WITH

A LITTLE MORE WEIGHT PLACED ON THE TAFB ESTIMATE OF T5.0/90 KT.



NORMAN'S INITIAL MOTION ESTIMATE IS 270/10 KT. THE AFOREMENTIONED

EYE NOTED IN THE MICROWAVE PASSES GREATLY HELPED WITH DETERMINING

THE CYCLONE'S LOCATION AND PAST MOTION. OTHER THAN SOME SLIGHT

FORWARD SPEED ADJUSTMENTS MADE IN THE FIRST 24 HOURS DUE TO THE

FASTER INITIAL MOTION, NO SIGNIFICANT CHANGES WERE REQUIRED TO THE

PREVIOUS TRACK FORECAST. NORMAN IS FORECAST TO MOVE WESTWARD TO

WEST-NORTHWESTWARD FOR THE NEXT SEVERAL DAYS AS THE HURRICANE MOVES

ALONG THE SOUTHERN PERIPHERY OF STRONG DEEP-LAYER RIDGE TO THE

NORTH. THE MODELS ARE IN EXCELLENT AGREEMENT ON THE TRACK OF NORMAN

THROUGH 72 H, AND THEN DIVERGE NOTICEABLY AFTER THAT TIME WITH THE

GFS TAKING NORMAN MORE WESTWARD IN THE GENERAL DIRECTION OF THE

HAWAIIAN ISLANDS, WHEREAS THE ECMWF, HWRF, AND HMON MODELS KEEP

NORMAN WELL TO THE NORTHEAST OF THE ISLANDS. THE OFFICIAL FORECAST

TRACK LIES CLOSE TO THE MIDDLE OF THE TIGHTLY PACKED GUIDANCE

ENVELOPE THROUGH 72 H, AND THEN IS CLOSE TO THE CONSENSUS AIDS HCCA