WTPZ44 KNHC 312032 RRA

TCDEP4



TROPICAL STORM LIDIA DISCUSSION NUMBER   9

NWS NATIONAL HURRICANE CENTER MIAMI FL       EP142017

300 PM MDT THU AUG 31 2017



SATELLITE IMAGERY INDICATES THAT LIDIA CONTINUES TO BECOME BETTER

ORGANIZED, WITH CONVECTIVE BANDS NOW WRAPPING MOST OF THE WAY

AROUND A RAGGED CLEAR-AIR CENTER.  RECENT SURFACE OBSERVATIONS FROM

THE CABO SAN LUCAS AREA SUPPORT INCREASING THE INITIAL INTENSITY TO

55 KT, ALTHOUGH IT IS UNCLEAR HOW MUCH TERRAIN ENHANCEMENT OF THESE

WINDS IS OCCURRING.



THE INITIAL MOTION IS NORTH-NORTHWESTWARD OR 335/7 KT BETWEEN A

MID-LEVEL ANTICYCLONE CENTERED OVER CENTRAL MEXICO AND A MID- TO

UPPER-LEVEL LOW LOCATED TO THE WEST OVER THE PACIFIC.  THIS MOTION

SHOULD CONTINUE FOR THE NEXT 24 H OR SO.  AFTER THAT TIME, A

MID-LEVEL ANTICYCLONE OVER THE SOUTHWESTERN UNITED STATES SHOULD

BECOME THE MAIN STEERING INFLUENCE FROM 48-120 H, FORCING LIDIA TO

TURN NORTHWESTWARD AND EVENTUALLY WESTWARD.  THE GUIDANCE HAS BECOME

SOMEWHAT LESS TIGHTLY SPREAD, AS THE GFS IS CURRENTLY A RIGHT

OUTLIER SHOWING A MOTION INTO THE NORTHERN GULF OF CALIFORNIA.

GIVEN THE LACK OF SUPPORT FOR THIS SCENARIO FROM THE OTHER MODELS,

THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK AND A LITTLE

SOUTH OF THE CONSENSUS MODELS



ADDITIONAL STRENGTHENING IS POSSIBLE THIS EVENING BEFORE THE CENTER

MOVES OVER THE BAJA CALIFORNIA PENINSULA, AND WHILE THE CHANCE

OF LIDIA BECOMING A HURRICANE IS LOW IT IS STILL NON-ZERO.

WEAKENING IS EXPECTED AFTER 12 H DUE TO THE CENTER MOVING UP THE

SPINE OF THE BAJA CALIFORNIA PENINSULA, BUT TROPICAL-STORM-FORCE

WINDS ARE LIKELY TO SPREAD UP THE GULF OF CALIFORNIA WELL EAST OF