WTPZ45 KNHC 260239 RRA

TCDEP5



TROPICAL STORM ROSA DISCUSSION NUMBER   4

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP202018

900 PM MDT TUE SEP 25 2018



SATELLITE IMAGERY INDICATES THAT ROSA IS STILL STRENGTHENING. THE

TROPICAL STORM HAS IMPRESSIVE BANDING FEATURES THAT WRAP

CYCLONICALLY FROM THE NORTHWEST TO NORTHEAST QUADRANT, THOUGH A DRY

SLOT HAS RECENTLY BEEN OBSERVED INFRINGING ON THE STORM'S DEVELOPING

INNER-CORE. THE MOST RECENT DVORAK INTENSITY ESTIMATES FROM TAFB AND

SAB ARE 55 KT, SO THE INITIAL INTENSITY HAS BEEN RAISED TO THAT

VALUE.



ALL OF THE INTENSITY GUIDANCE SUGGESTS THAT RAPID INTENSIFICATION

(RI) IS EITHER ALREADY UNDERWAY OR IMMINENT. SSMIS IMAGERY FROM

AROUND 2300 UTC APPEARED TO CONFIRM THE ONSET OF RI WITH THE

DEVELOPMENT OF A SMALL LOW-LEVEL EYE-LIKE FEATURE THAT HAS BEEN

ASSOCIATED WITH RAPID INTENSIFICATION IN PAST TROPICAL CYCLONES.

ALTHOUGH MORE RECENT IMAGERY INDICATES THIS FEATURE MAY HAVE BEEN

DISRUPTED BY THE AFOREMENTIONED DRY SLOT, THE MODELS SUGGEST THAT

THIS DISRUPTION MAY NOT LAST LONG. THE NHC FORECAST THEREFORE

CONTINUES TO SHOW RI, AND NOW CALLS FOR ROSA TO BECOME A MAJOR

HURRICANE IN ABOUT 36 H. BEYOND THAT TIME, THE HURRICANE IS EXPECTED

TO REMAIN IN A FAIRLY FAVORABLE ENVIRONMENT THROUGH FRIDAY, HOWEVER,

EYEWALL REPLACEMENT CYCLES COULD LIMIT THE EXTENT TO WHICH ROSA

INTENSIFIES ONCE IT NEARS MAJOR HURRICANE STRENGTH. BY THE WEEKEND,

COOLER SSTS AND A DRIER SURROUNDING ENVIRONMENT SHOULD CAUSE ROSA TO

BEGIN WEAKENING. THE NHC INTENSITY FORECAST IS SIMILAR TO THE

PREVIOUS ADVISORY, AND IS GENERALLY CLOSE TO HCCA, ESPECIALLY BEYOND

48 H.



ROSA IS MOVING STEADILY WEST-NORTHWESTWARD, OR 285/8 KT.  A MID-