WTPZ43 KNHC 080232 RRA

TCDEP3



TROPICAL STORM KRISTY DISCUSSION NUMBER   5

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132018

800 PM PDT TUE AUG 07 2018



KRISTY HAS BECOME A LITTLE LESS ORGANIZED THIS EVENING.  AN UPPER

TROPOSPHERIC LOW SITUATED TO THE NORTHEAST OF KRISTY IS

PRODUCING MODERATE NORTHWESTERLY SHEAR WHICH HAS DEGRADED THE

CYCLONE'S CLOUD PATTERN.  A 2035 UTC AMSR2 OVERPASS REVEALED THAT

THE SURFACE CENTER WAS PARTIALLY EXPOSED TO THE NORTH OF THE

CONVECTIVE BANDING FEATURES.  THE SUBJECTIVE DVORAK INTENSITY

ESTIMATES FROM TAFB AND SAB HAVE DECREASED AS WELL, SO THE INITIAL

INTENSITY FOR THIS ADVISORY IS LOWERED TO 40 KT.



STATISTICAL AND GLOBAL MODELS ALL SHOW THE UPPER LOW TO THE

NORTHEAST OF KRISTY WEAKENING AND LIFTING OUT IN 24 HOURS OR SO,

WHICH SHOULD PROVIDE A MORE CONDUCIVE UPPER WIND ENVIRONMENT FOR

INTENSIFICATION, AT LEAST THROUGH MID-PERIOD.  AFTERWARDS, A

WEAKENING TREND SHOULD COMMENCE DUE TO AN INTRUDING DRIER/STABLE AIR

MASS AND COOLER OCEANIC SEA SURFACE TEMPERATURES.  THE HWRF AND HCCA

SHOW KRISTY BECOMING A HURRICANE IN 48 HOURS, WHICH STILL SEEMS

QUITE REASONABLE AND IS REFLECTED IN THE FORECAST.  ALL OF THE OTHER

GUIDANCE REACHES JUST BELOW 65 KT.  THE NHC INTENSITY FORECAST IS

BASED PRIMARILY ON THESE TWO MODELS, AND INDICATES A PEAK

INTENSITY OF 65 KT IN 48 HOURS.



THE INITIAL MOTION IS ESTIMATED TO BE 285/7 KT, AND KRISTY IS BEING

STEERED BY A NARROW MID-LEVEL RIDGE TO THE NORTHEAST.  A COMPLEX

SYNOPTIC STEERING PATTERN COMPRISED OF AN APPROACHING DEEP-LAYER LOW

PRESSURE SYSTEM TO THE NORTHWEST OF THE TROPICAL STORM, AND JOHN TO

THE NORTHEAST, IS FORECAST BY MOST OF THE GLOBAL AND REGIONAL MODELS