WTPZ43 KNHC 081433 RRA

TCDEP3



TROPICAL STORM KRISTY DISCUSSION NUMBER   7

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132018

800 AM PDT WED AUG 08 2018



KRISTY HAS CONTINUES TO HAVE THE STRUCTURE OF A STRONGLY SHEARED

TROPICAL CYCLONE. THE LOW-LEVEL CENTER HAS BEEN DIFFICULT TO

IDENTIFY OVERNIGHT, BUT RECENT MICROWAVE DATA INDICATES THAT IT IS

DISPLACED TO THE NORTHWEST OF THE PRIMARY CONVECTIVE MASS. THE

INITIAL INTENSITY HAS BEEN HELD AT 40 KT BASED ON A BLEND OF DVORAK

FINAL-T NUMBERS FROM TAFB AND SAB.



ALTHOUGH THE LOW-LEVEL CENTER HAS BEEN SOMEWHAT DIFFICULT TO TRACK,

IT APPEARS THAT KRISTY HAS BEGUN TO TURN WEST-NORTHWESTWARD, AND THE

INITIAL MOTION ESTIMATE IS 290/7 KT. LITTLE CHANGE HAS BEEN MADE TO

THE OFFICIAL TRACK FORECAST, BUT CONFIDENCE REMAINS VERY LOW. A

BREAK IN THE SUBTROPICAL RIDGE CREATED BY HURRICANE JOHN SHOULD

ALLOW KRISTY TO CONTINUE TURNING, RESULTING IN A NORTHWARD MOTION BY

THURSDAY. BEYOND THAT TIME, THE MODEL SPREAD REMAINS HIGH, FUELED BY

A COMBINATION OF UNCERTAINTY AS TO HOW MUCH JOHN AND KRISTY WILL

DIRECTLY INTERACT, AND HOW MUCH KRISTY WILL RESPOND TO AN

UPPER-LEVEL TROUGH TO THE NORTHWEST. THE GFS IS A NOTABLE OUTLIER ON

THE EAST SIDE OF THE GUIDANCE ENVELOPE, AND IS THE ONLY MODEL

SHOWING KRISTY WRAPPING AROUND THE CIRCULATION OF JOHN. FOR NOW, THE

NHC FORECAST CONTINUES TO DOWNPLAY THIS POSSIBILITY, AND IS A LITTLE

TO THE WEST OF THE MULTI-MODEL CONSENSUS.



THE INTENSITY GUIDANCE SPREAD IS ALSO HIGH, RANGING FROM THE HWRF

WHICH MAKES KRISTY A HURRICANE, TO THE SHIPS AND LGEM WHICH FORECAST

ONLY GRADUAL WEAKENING. SINCE THE SHEAR IS FORECAST TO DECREASE OVER

THE NEXT 12 TO 24 HOURS, AND KRISTY WILL BE MOVING AWAY FROM THE