WTPA41 PHFO 031445
TCDCP1

TROPICAL DEPRESSION LANA DISCUSSION NUMBER  17
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP062009
500 AM HST MON AUG 03 2009

THE STRONG VERTICAL WIND SHEAR CONTINUES TO TAKE ITS TOLL ON 
TROPICAL DEPRESSION LANA. THE LATEST UW-CIMSS ENVIRONMENTAL VERTICAL 
WIND SHEAR ANALYSIS INDICATED VALUES OF 25 KT FROM 230 DEG. THE 
CENTER OF THE LOW LEVEL CIRCULATION CENTER...WHICH HAS BEEN DEVOID 
OF DEEP CONVECTION SINCE SUNDAY...WAS DIFFICULT TO LOCATE AT 200 AM 
HST...1200 UTC...THIS MORNING. FIXES FROM PHFO...JTWC AND SAB WERE 
RATHER TIGHTLY CLUSTERED...EVEN THOUGH THE ACTUAL CIRCULATION HAS 
BECOME MUCH LESS DEFINED IN INFRARED IMAGERY DURING THE PAST 6 
HOURS. BASED ON THE LATEST INITIAL POSITION...LANA IS MOVING 280/14. 
ALL OF THE SATELLITE AGENCIES INDICATED THE SYSTEM WAS TOO WEAK TO 
CLASSIFY...WITH PHFO GIVING A T-NUMBER OF 1.5 BASED ON MET. THE 
CURRENT UW-CIMSS INTENSITY ANALYSIS INDICATED A CI OF 1.0. 
THEREFORE...THE INITIAL INTENSITY IS REDUCED TO 25 KT. 

THE STEERING OF TROPICAL DEPRESSION LANA...WHICH IS BEING CARRIED BY 
THE LOW-LEVEL FLOW DUE TO ITS LACK OF DEEP CONVECTION...IS BEING 
CONTROLLED BY THE SUBTROPICAL RIDGE LOCATED TO THE NORTH OF THE 
SYSTEM NEAR LATITUDE 28N. THIS RIDGING IS FORECAST TO REMAIN IN 
PLACE FOR AT LEAST THE NEXT FEW DAYS...SO NO MAJOR CHANGES TO THE 
FORECAST TRACK WERE MADE FOR THIS PACKAGE. HOWEVER...THE FORECAST 
TRACK FOR LANA...OR ITS REMNANTS...WAS NUDGED SLIGHTLY TO THE RIGHT 
IN DEFERENCE TO BAMS/BAMM...AS WELL AS THE TRACK CONSENSUS.

IN REGARD TO THE INTENSITY FORECAST...DESPITE WARM SSTS AND 
INCREASINGLY FAVORABLE OCEAN HEAT CONTENT BASED ON THE LATEST CIRA 
ANALYSIS...THE STRONG VERTICAL WIND SHEAR WILL BE THE LIMITING 
FACTOR FOR LANA AS A VIABLE TROPICAL CYCLONE. THE LATEST SHIPS 
FORECAST INDICATES SHEAR WILL BE INCREASING TO 30 KT OR GREATER 
LATER TODAY. THIS FORECAST APPEARS TO BE REASONABLE SINCE WATER 
VAPOR IMAGERY DEPICTS AN UPPER TROPOSPHERIC LOW CENTERED NEAR 17N 
168W...OR ABOUT 350 NM NORTHWEST OF LANA. THE GFS MODEL INDICATES 
THIS LOW WILL TRAVEL WESTWARD AS A COMPANION OF LANA DURING THE NEXT 
FEW DAYS. THERE DOES NOT APPEAR TO BE A CHANCE FOR THE SYSTEM TO 
EVER RECOVER FROM THIS HOSTILE ENVIRONMENT. THEREFORE...THIS WILL BE 
THE LAST ADVISORY FOR TROPICAL DEPRESSION LANA ISSUED BY THE CENTRAL 
PACIFIC HURRICANE CENTER.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/1500Z 14.9N 163.6W    25 KT...DISSIPATING
 12HR VT     04/0000Z 15.3N 165.8W    20 KT...REMNANT LOW
 24HR VT     04/1200Z 15.8N 168.7W    20 KT...REMNANT LOW
 36HR VT     05/0000Z 16.3N 171.6W    20 KT...REMNANT LOW
 48HR VT     05/1200Z 16.8N 174.5W    20 KT...REMNANT LOW
 
$$
FORECASTER HOUSTON