WTPZ42 KNHC 061522 RRA

TCDEP2



TROPICAL STORM JOHN DISCUSSION NUMBER   4...CORRECTED

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122018

900 AM MDT MON AUG 06 2018



CORRECTED TO REMOVE THE PERCENT SYMBOLS IN THE TEXT



EARLY MORNING VISIBLE SATELLITE IMAGES AND RECENT MICROWAVE DATA

SHOW THAT JOHN CONTINUES TO QUICKLY BECOME BETTER ORGANIZED.

BANDING FEATURES NOW WRAP NEARLY COMPLETELY AROUND THE CENTER, WITH

THE DEVELOPMENT OF A FAIRLY SYMMETRIC CDO.  ONE-MINUTE GOES-16

IMAGERY ALSO SHOW SEVERAL OVERSHOOTING CONVECTIVE CLOUD TOPS NEAR

AND TO THE EAST OF THE CENTER.  A TAFB DVORAK ESTIMATE OF T3.5 WAS

THE BASIS OF THE 1200 UTC INTENSITY OF 55 KT, BUT WITH THE INCREASE

IN ORGANIZATION SINCE THAT TIME, AND RAW OBJECTIVE T-NUMBERS ABOVE

4.0 FOR THE PAST FEW HOURS, THE ADVISORY INTENSITY HAS BEEN

INCREASED TO 60 KT.



JOHN IS WITHIN A VERY FAVORABLE ENVIRONMENT FOR INTENSIFICATION.

THE HURRICANE WILL BE MOVING OVER SSTS AROUND 30C, AND IN A LOW

SHEAR AND MOIST ENVIRONMENT.  THESE CONDITIONS ARE EXPECTED TO

ALLOW FOR RAPID STRENGTHENING DURING THE NEXT DAY OR SO.  THE SHIPS

RAPID INTENSIFICATION INDEX SHOWS A NEARLY 80 PERCENT CHANCE OF RI

OVER THE THE NEXT 24 H, AND DTOPS GIVES AN 80 PERCENT CHANCE OF A

40 KT INCREASE IN INTENSITY DURING THE NEXT 24 H.  BASED ON THESE

DATA AND THE VERY AGGRESSIVE GUIDANCE, THE NHC FORECAST CALLS FOR A

40 KT INCREASE IN STRENGTH FROM 1200 THIS MORNING THROUGH 1200 UTC

TUESDAY. THE NHC FORECAST CALLS FOR A PEAK INTENSITY THAT IS CLOSE

TO THE FSSE AND HCCA MODELS IN 36 TO 48 HOURS.  AFTER THAT TIME,

JOHN WILL BE MOVING OVER COOLER WATERS AND INTO A MORE STABLE

ENVIRONMENT WHICH IS EXPECTED TO CAUSE RAPID WEAKENING.