WTPZ43 KNHC 252032 RRA

TCDEP3



TROPICAL DEPRESSION EIGHTEEN-E DISCUSSION NUMBER   2

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP182016

200 PM PDT SUN SEP 25 2016



THE OVERALL ORGANIZATION OF THE DEPRESSION HAS NOT CHANGED MUCH

SINCE THIS MORNING.  THE CENTER IS EXPOSED TO THE NORTH OF THE MAIN

AREA OF THUNDERSTORM ACTIVITY, WITH SOME BANDING NOTED OVER THE

NORTHEASTERN QUADRANT.  VISIBLE IMAGERY SHOWS THAT THERE ARE

SEVERAL SMALLER SWIRLS ROTATING AROUND THE MEAN CENTER.  DVORAK

INTENSITY ESTIMATES ARE T2.5/35 KT FROM TAFB AND T1.5/25 KT FROM

SAB, SO THE INITIAL INTENSITY REMAINS 30 KT FOR THIS ADVISORY.



THE DEPRESSION IS FORECAST TO REMAIN OVER WARM WATER AND TO BE IN A

LOW-SHEAR ENVIRONMENT DURING THE NEXT 12 TO 24 HOURS, BUT THE LARGE

AND SPRAWLING NATURE OF THE SYSTEM SUGGESTS THAT ANY INTENSIFICATION

SHOULD BE SLOW TO OCCUR.  BY LATE MONDAY, THE CYCLONE WILL BE

MOVING INTO AN AREA OF INCREASING SOUTHWESTERLY SHEAR, AND BY

TUESDAY THE SYSTEM WILL BE MOVING OVER COOLER WATERS AND INTO

A MORE STABLE AIR MASS.  THESE CONDITIONS SHOULD RESULT IN WEAKENING

WITHIN 48 HOURS, AND THE SYSTEM IS EXPECTED TO BECOME A REMNANT LOW

IN ABOUT 3 DAYS.  THE NHC INTENSITY FORECAST IS UNCHANGED FROM THE

PREVIOUS ADVISORY AND IS ONCE AGAIN IN BEST AGREEMENT WITH THE IVCN

CONSENSUS MODEL.



THE DEPRESSION IS MOVING NORTHWARD OR 360/6 KT.  THE TRACK FORECAST

REASONING IS UNCHANGED FROM THE PREVIOUS ADVISORY.  THE CYCLONE

SHOULD MOVE NORTH-NORTHEASTWARD AROUND THE WESTERN PORTION OF A

WEAK RIDGE THAT EXTENDS SOUTHWESTWARD FROM SOUTHERN MEXICO.

ALTHOUGH MOST OF THE TRACK MODELS AGREE WITH THIS SCENARIO, THE

GFS AND GFDL TAKE A STRONGER AND DEEPER CYCLONE MORE NORTHEASTWARD,=