WTPZ45 KNHC 282055 RRA

TCDEP5



HURRICANE ROSA DISCUSSION NUMBER  15

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP202018

200 PM PDT FRI SEP 28 2018



ROSA'S APPEARANCE HAS RAPIDLY DETERIORATED SINCE THIS MORNING.

THERE IS STILL EVIDENCE OF AN ONGOING EYEWALL REPLACEMENT CYCLE,

AND AN APPARENT MOAT REGION HAS OCCASIONALLY BEEN APPARENT IN

CONVENTIONAL SATELLITE DATA DURING THE PAST SEVERAL HOURS.  THE SLOW

MOTION OF THE HURRICANE SINCE LAST NIGHT COULD ALSO BE CAUSING

UPWELLING THAT WOULD LEAD TO FURTHER WEAKENING.  SATELLITE

INTENSITY ESTIMATES FROM ALL AGENCIES HAVE DROPPED SUBSTANTIALLY

ACCORDINGLY, AND THE INITIAL INTENSITY HAS BEEN LOWERED TO 105 KT,

BASED ON A BLEND OF FINAL-T AND CI NUMBERS FROM TAFB AND SAB.



ROSA IS STILL MOVING NORTHWESTWARD, WITH AN INITIAL MOTION OF

325/5 KT. THE MODEL SPREAD HAS INCREASED A LITTLE, WITH THE GFS AND

ITS ASSOCIATED REGIONAL MODELS SHOWING A SLIGHTLY RIGHT (SOUTHEAST)

TRACK, COMPARED TO EARLIER CYCLES, WHILE THE ECMWF HAS SHIFTED AN

EQUAL AMOUNT TO THE LEFT (NORTHWEST). THE CONSENSUS MODELS HAVE NOT

CHANGED MUCH AS A RESULT OF THESE OFFSETTING MODEL TRENDS, SO ALMOST

NO CHANGE WAS MADE TO THE NHC TRACK FORECAST. ROSA IS STILL EXPECTED

TO TURN NORTHWARD, AND THEN NORTH-NORTHEASTWARD AHEAD OF A MID- TO

UPPER-LEVEL TROUGH APPROACHING FROM THE NORTHWEST.  THE CYCLONE

SHOULD THEN ACCELERATE A LITTLE AS IT APPROACHES THE NORTHERN COAST

OF THE BAJA CALIFORNIA PENINSULA EARLY NEXT WEEK.



AT THIS POINT, THE STRUCTURE OF ROSA HAS DEGRADED TO THE POINT THAT

SUBSTANTIAL RESTRENGTHENING APPEARS UNLIKELY.  SINCE THE HURRICANE

STILL HAS ABOUT 24-36 HOURS BEFORE IT REACHES MUCH COOLER SSTS,