WTNT44 KNHC 300849 RRA

TCDAT4



HURRICANE MATTHEW DISCUSSION NUMBER   9

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142016

500 AM AST FRI SEP 30 2016



THERE ARE NO DATA CURRENTLY AVAILABLE FROM THE INNER CORE OF

MATTHEW, SO IT IS UNCLEAR WHETHER THE EARLIER RAPID INTENSIFICATION

IS CONTINUING.  A WELL-DEFINED ELLIPTICAL EYE IS SEEN IN DATA FROM

THE CURACAO RADAR.  HOWEVER, THE LATEST SATELLITE IMAGERY SHOWS

THAT THE CENTRAL CONVECTION IS SOMEWHAT ASYMMETRIC AND THAT AN EYE

IS YET TO FORM.  SATELLITE INTENSITY ESTIMATES ARE 90 KT FROM TAFB

AND 77 KT FROM SAB.  BASED ON CONTINUITY FROM THE PREVIOUS ADVISORY

AND NO IMPROVEMENT IN THE SATELLITE SIGNATURE, THE INITIAL INTENSITY

IS HELD AT A POSSIBLY CONSERVATIVE 85 KT.  IT IS NOTABLE THAT THE

RAPID INTENSIFICATION HAS OCCURRED DESPITE AN ONGOING 20 KT OF

SOUTHWESTERLY VERTICAL WIND SHEAR.



THE INITIAL MOTION IS 265/12.  THERE IS LITTLE CHANGE TO THE TRACK

FORECAST PHILOSOPHY FROM THE PREVIOUS ADVISORY.  A LOW- TO

MID-LEVEL RIDGE TO THE NORTH OF MATTHEW SHOULD KEEP IT MOVING

WESTWARD OR SOUTH OF WESTWARD FOR THE NEXT 36 HOURS WITH SOME

DECREASE IN FORWARD SPEED.  FROM 48-120 HOURS, THE RIDGE IS

FORECAST TO WEAKEN AND SHIFT EASTWARD AS A MID- TO UPPER-LEVEL

TROUGH MOVES INTO THE CENTRAL AND EASTERN GULF OF MEXICO.  THIS

EVOLUTION SHOULD CAUSE MATTHEW TO TURN NORTHWESTWARD AND THEN

NORTHWARD.  THERE IS A SIGNIFICANT SPREAD IN WHERE THE TURN WILL

OCCUR AND HOW FAST MATTHEW WILL MOVE AFTERWARDS.  THE ECMWF AND

UKMET ARE ON THE EASTERN SIDE OF THE GUIDANCE ENVELOPE AND SLOWER

THAN THE OTHER MODELS, WHILE THE GFS AND CANADIAN MODELS ARE TO THE

LEFT OF THE CENTER OF THE GUIDANCE ENVELOPE AND MUCH FASTER.  THE=