WTPZ42 KNHC 150236 RRA

TCDEP2



TROPICAL DEPRESSION TWENTY-TWO-E DISCUSSION NUMBER   3

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP222018

1000 PM CDT SUN OCT 14 2018



FOR THE FIRST TIME IN THE DEPRESSION'S (AND ITS PREDECESSOR LOW'S)

EXISTENCE, DEEP CONVECTION HAS PERSISTED FOR MORE THAN A FEW HOURS.

THE CONVECTIVE CANOPY HAS BEEN SLOWLY EXPANDING, ALTHOUGH IT IS

STILL A LITTLE RESTRICTED ON THE EASTERN SIDE DUE SOME EASTERLY

SHEAR.  BASED ON MICROWAVE DATA, THE STRUCTURE OF THE CYCLONE HAS

BEEN SLOW TO IMPROVE IN ORGANIZATION, AND CONSENSUS T2.0S FROM TAFB

AND SAB SUPPORT MAINTAINING A 30-KT INITIAL INTENSITY.



THE DEPRESSION IS LOCATED NEAR THE WESTERN EDGE OF A MID-LEVEL

RIDGE, WITH A DEEP-LAYER TROUGH LOCATED NOT TOO FAR TO THE NORTH

ACROSS NORTHWESTERN MEXICO AND THE WESTERN UNITED STATES.  ITS

POSITION PLACES THE DEPRESSION WITHIN WEAK STEERING CURRENTS, AND

THE SYSTEM IS LIKELY TO DRIFT WEST-NORTHWESTWARD OR EVEN MEANDER AT

SPEEDS OF LESS THAN 5 KT FOR MUCH OF THE FORECAST PERIOD.  THE TRACK

GUIDANCE HAS SHIFTED A LITTLE MORE TO THE NORTHWEST ON THIS CYCLE,

AND THE NHC FORECAST HAS THEREFORE BEEN ADJUSTED NORTH OF THE

PREVIOUS OFFICIAL FORECAST, ALTHOUGH NOT AS FAR AS THE TVCN

MULTI-MODEL CONSENSUS NOR THE HCCA AID.  DESPITE THIS ADJUSTMENT,

THE CYCLONE IS EXPECTED TO REMAIN SMALL, WHICH SHOULD KEEP

TROPICAL-STORM-FORCE WINDS OFFSHORE OF THE COAST OF MEXICO.



THE FORECAST REASONING FOR THE FUTURE INTENSITY HAS CHANGED

SUBSTANTIALLY.  FOR THE FIRST 3 DAYS, VERTICAL SHEAR IS EXPECTED TO

GRADUALLY DECREASE, AND THE CYCLONE'S SMALL SIZE WILL MAKE IT PRONE

TO SIGNIFICANT STRENGTHENING DURING THAT PERIOD.  IN FACT, BASED ON