WTPZ42 KNHC 141500 RRA

TCDEP2



TROPICAL DEPRESSION TWENTY-TWO-E DISCUSSION NUMBER   1

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP222018

1000 AM CDT SUN OCT 14 2018



A SMALL LOW PRESSURE SYSTEM THAT THE NHC HAS BEEN TRACKING FOR THE

PAST COUPLE OF DAYS HAS FINALLY ACQUIRED ENOUGH ORGANIZED CONVECTION

TO BE DESIGNATED A TROPICAL DEPRESSION, WHICH IS LOCATED LESS THAN

100 NMI OFF THE SOUTHWESTERN COAST OF MEXICO. CLOUD TOPS NEAR THE

CENTER HAVE RECENTLY BEEN AS COLD AS -90C, AND SATELLITE INTENSITY

ESTIMATES ARE T1.5/25 KT FROM BOTH TAFB AND SAB. THE INITIAL

INTENSITY IS SET AT 30 KT BASED ON AN EARLIER OSCAT/SCATSAT

SCATTEROMETER PASS THAT HAD A FEW UNCONTAMINATED WIND VECTORS

LOCATED JUST NORTH OF A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER,

WHICH IS SIMILAR TO YESTERDAY'S ASCAT PASSES.



THE INITIAL MOTION ESTIMATE IS 295/05 KT. THE SMALL CYCLONE IS

FORECAST BY THE GLOBAL AND REGIONAL MODELS TO MOVE ONLY SLOWLY

WESTWARD TO SOUTHWESTWARD AT LESS THAN 5 KT FOR THE NEW FEW DAYS DUE

TO THE SYSTEM BEING CAUGHT IN A BREAK IN THE SUBTROPICAL RIDGE THAT

EXTENDS FROM CENTRAL MEXICO SOUTHWESTWARD INTO THE EASTERN PACIFIC.

BY DAYS 4 AND 5, THE RIDGE IS FORECAST TO BUILD WESTWARD TO THE

NORTH OF THE SYSTEM, ACTING TO NUDGE THE CYCLONE WESTWARD AT A

SLIGHTLY FASTER FORWARD SPEED. THE NHC FORECAST TRACK LIES BETWEEN

THE CONSENSUS MODELS TVCE AND HCCA.



THE ENVIRONMENT IS EXPECTED TO BE SOMEWHAT CONDUCIVE FOR GRADUAL

STRENGTHENING OF THE CYCLONE THROUGHOUT THE FORECAST PERIOD. THE

STATISTICAL-DYNAMICAL MODELS SHIPS AND LGEM AREN'T OVERLY ENTHUSED

WITH INTENSIFYING THE SYSTEM, BUT THAT IS MAINLY DUE TO THE HIGH

SHEAR VALUES CALCULATED FROM THE VERY POLEWARD TABM BETA-ADVECTION