WTPA41 PHFO 022045
TCDCP1

TROPICAL STORM LANA DISCUSSION NUMBER  14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP062009
1100 AM HST SUN AUG 02 2009

AT 800 AM HST...1800 UTC...LANA SHOWED SIGNS OF WEAKENING WITH DEEP
CONVECTION DETERIORATING IN THE NORTHEAST QUADRANT OF THE SYSTEM.
THE LOW LEVEL CLOUD CENTER IS GRADUALLY BECOMING MORE REMOVED FROM
THIS AREA OF DEEP CONVECTION. PHFO AND SAB CAME UP WITH FINAL T
NUMBERS OF 3.0 WHILE JTWC WENT WITH 2.5. DEEP CONVECTION HAS HAD A
HISTORY OF PULSING WITH THIS SYSTEM. THE OFFICIAL INTENSITY 
ESTIMATE REMAINS AT 45 KT BUT THE CURRENT INTENSITY MAY BE A BIT 
GENEROUS IF DEEP CONVECTION DOES NOT REFORM NEAR THE SYSTEMS CENTER 
OVER THE NEXT SEVERAL HOURS.

LANA LIES IN DEEP EASTERLY FLOW SOUTH OF A SUBTROPICAL RIDGE LOCATED
NORTH OF HAWAII. GLOBAL MODELS ARE IN GOOD AGREEMENT IN BUILDING
THE LOW AND MID LEVEL RIDGE TO THE WEST...KEEPING LANA WELL WITHIN
THE BROAD EASTERLY TRADE WIND BELT. THE OFFICIAL TRACK REMAINS 
NEARLY THE SAME AS THE PREVIOUS FORECAST AND LIES JUST SOUTH OF THE
VAST MAJORITY OF MODEL CONSENSUS WHICH IS CLOSELY GROUPED OVERALL.
FORWARD MOTION REMAINS IN GOOD AGREEMENT WITH MOST OF THE OBJECTIVE 
AIDES AND IS AN EXTENSION OF THE OLD TRACK.

AN ELONGATED UPPER LEVEL TROUGH LIES TO THE WEST AND SOUTHWEST OF
KAUAI. THE UW-CIMSS OUTPUT SHOWS SOUTH TO SOUTHEASTERLY SHEAR
ESTIMATED TO BE ABOUT 25 KT IN THE VICINITY OF LANA. THIS SHOULD
CONTINUE TO INHIBIT ANY CHANCE OF RE-INTENSIFICATION. THIS TROUGH
IS EXPECTED TO MOVE WESTWARD OVER THE NEXT FEW DAYS AND GRADUALLY
WEAKEN WITH TIME. WITH LANA EXPECTED TO REMAIN IN A HOSTILE SHEAR
ENVIRONMENT...GRADUAL WEAKENING IS EXPECTED THROUGH THE FORECAST
PERIOD WHICH IS IN GENERAL AGREEMENT WITH INTENSITY GUIDANCE...WITH 
ONLY THE UKMET AND SHIFOR5 KEEPING LANA AS A WEAK TROPICAL STORM 
THROUGH 120 HOURS. THIS MAY BE DUE TO WARMER SEA SURFACE 
TEMPERATURES ALONG THE FORECAST TRACK WELL SOUTHWEST OF THE MAIN 
HAWAIIAN ISLANDS.   

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      02/2100Z 14.5N 158.9W    45 KT
 12HR VT     03/0600Z 14.6N 160.9W    40 KT
 24HR VT     03/1800Z 15.0N 163.7W    35 KT
 36HR VT     04/0600Z 15.3N 166.5W    35 KT
 48HR VT     04/1800Z 15.6N 169.6W    30 KT
 72HR VT     05/1800Z 16.2N 175.3W    25 KT...DISSIPATING
 96HR VT     06/1800Z 16.8N 179.0E    20 KT...REMNANT LOW
120HR VT     07/1800Z 17.4N 173.7E    20 KT...REMNANT LOW
 
$$
FORECASTER BURKE