WTPZ43 KNHC 220249 RRA

TCDEP3



TROPICAL DEPRESSION EIGHT-E DISCUSSION NUMBER   2

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP082016

800 PM PDT THU JUL 21 2016



VISIBLE SATELLITE IMAGERY AND A 2309 UTC SSMIS MICROWAVE OVERPASS

SHOWED THAT THE DEPRESSION'S CENTER OF CIRCULATION WAS LOCATED NEAR

THE NORTHEASTERN EDGE OF THE CLOUD MASS, INDICATIVE THAT SOME

NORTHEASTERLY SHEAR IS IMPINGING ON THE CLOUD PATTERN.  THE DVORAK

SATELLITE INTENSITY ESTIMATES HAVE NOT CHANGED DURING THE PAST 6

HOURS, AND THE INITIAL INTENSITY REMAINS AT 30 KT.  LIGHT TO

MODERATE NORTHEASTERLY SHEAR IS EXPECTED TO CONTINUE FOR THE NEXT

COUPLE OF DAYS AS THE DEPRESSION TRAVERSES WARM WATER.  GRADUAL

STRENGTHENING SEEMS REASONABLE AND THIS FORECAST TREND IS SUPPORTED

BY MOST OF THE STATISTICAL-DYNAMICAL GUIDANCE.  BEYOND DAY 3,

HOWEVER, THE DEPRESSION IS EXPECTED TO ENCOUNTER DECREASING SSTS OF

BELOW 25C, AND MOVE INTO A MORE STABLE THERMODYNAMIC ENVIRONMENT

WHICH SHOULD INFLUENCE SLOW WEAKENING THROUGH THE REMAINDER OF THE

PERIOD.  THE LATEST NHC FORECAST IS SIMILAR TO THE PREVIOUS ONE, AND

IS BASED PRIMARILY ON THE IVCN MULTI-MODEL GUIDANCE.



CONVENTIONAL SATELLITE POSITION FIXES AND A COUPLE OF MICROWAVE

OVERPASSES YIELD AN INITIAL MOTION ESTIMATE OF 295/11 KT, SOUTH OF

A STRONG SUBTROPICAL RIDGE ALONG 29N ORIGINATING FROM TEXAS/NORTHERN

MEXICO.  THIS RIDGE IS EXPECTED TO STEER THE CYCLONE GENERALLY

WEST-NORTHWESTWARD THROUGH THE 96 HOUR PERIOD.  AFTERWARD, THE

GLOBAL AND REGIONAL MODEL GUIDANCE STILL SHOWS INCREASING SPREAD

WITH TIME.  THE ECMWF IS BASICALLY THE OUTLIER THIS EVENING, SHOWING

A MUCH MORE NORTH-NORTHWESTWARD TURN INTO A BREAK IN THE RIDGE=