Image Department Meteorology
Meteorology_Home Weather_Server News/Seminars
People
Research
Academics Application Contact_Us

Hawaiian_Weather
US_Mainland_Weather
Tropical_Weather
Satellite_Imagery
Radar_Imagery
Marine
Numerical_Models
LAPS
Forecasts
Observations
Archive
Links Disclaimer
Space
SOEST_Home
University_of_Hawaii_Home

 396 
 WTPA41 PHFO 312057
 TCDCP1
 
 TROPICAL STORM LANA DISCUSSION NUMBER   6
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP062009
 1100 AM HST FRI JUL 31 2009
 
 AFTER ORGANIZATION DETERIORATED EARLY LAST NIGHT...A BURST OF
 CENTRAL CONVECTION AFTER 1200 UTC HELPED REINVIGORATE LANA.  DVORAK
 ESTIMATES FROM CPHC AND SAB CAME IN AT T3.5...OR 55 KT AND AN AMSU
 INTENSITY ESTIMATE AT 1437 UTC ALSO INDICATED 55 KT.  BASED ON THIS
 CONSENSUS...THE INITIAL INTENSITY WILL BE RAISED TO 55 KT. THE 37
 GHZ SSMI PASS FROM 1610 UTC HELPED LOCATE THE SYSTEM CENTER JUST
 EAST OF THE DEEP CONVECTION CENTROID. INFRARED AND VISIBLE
 SATELLITE IMAGES SHOW LANA/S OUTFLOW IS BEING RESTRICTED TO THE
 WEST AND SOUTHWEST. THIS INDICATES UPPER SOUTHWESTERLIES...AND
 INCREASED VERTICAL SHEAR...ARE STARTING TO AFFECT THE CYCLONE.
 
 LANA IS MOVING WESTWARD TO THE SOUTH OF A SUBTROPICAL RIDGE THAT
 WILL BUILD WESTWARD OVER THE NEXT SEVERAL DAYS. THIS WILL KEEP THE
 CYCLONE TRACK GENERALLY TOWARD THE WEST TO WEST-NORTHWEST THROUGH
 THE FORECAST PERIOD AND WELL SOUTH OF THE HAWAIIAN ISLANDS.  THE
 DYNAMICAL OBJECTIVE AIDS ARE TIGHTLY PACKED AND CONSISTENT WITH THE
 PREVIOUS PACKAGE. THUS...THE CURRENT FORECAST FOLLOWS THE PREVIOUS
 FORECAST AND IS CLOSE TO THE DYNAMICAL MODEL CONSENSUS...ESPECIALLY
 THROUGH 72 HOURS.
 
 IN TERMS OF INTENSITY...LANA MAY HAVE REACHED ITS PEAK. WHILE SST
 VALUES ARE MORE THAN ADEQUATE...UPPER LEVEL SOUTHWESTERLIES ARE
 EXPECTED TO INCREASE ALONG THE CYCLONE/S PROJECTED TRACK SO
 VERTICAL SHEAR WILL TAKE ITS TOLL...ESPECIALLY FROM 24 TO 36
 HOURS ONWARD. THE FORECAST FOLLOWS THE TREND OF THE ICON AND IVCN
 WITH SLOW WEAKENING FROM 24 THROUGH 48 HOURS FOLLOWED BY A MORE
 RAPID WEAKENING TO A REMNANT LOW BY 120 HOURS.  IF VERTICAL WIND
 SHEAR TAKES HOLD EARLIER...THE WEAKENING TREND WILL ALSO OCCUR
 EARLIER.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      31/2100Z 13.7N 147.7W    55 KT
  12HR VT     01/0600Z 14.1N 150.0W    55 KT
  24HR VT     01/1800Z 14.7N 152.9W    50 KT
  36HR VT     02/0600Z 15.2N 155.7W    45 KT
  48HR VT     02/1800Z 15.7N 158.3W    45 KT
  72HR VT     03/1800Z 16.5N 163.8W    35 KT
  96HR VT     04/1800Z 17.1N 169.5W    25 KT...DISSIPATING
 120HR VT     05/1800Z 17.6N 175.6W    20 KT...REMNANT LOW
  
 $$
 FORECASTER KODAMA
  
 
 
 
 
Return to the Tropical Systems Page for LANA

Back to main Tropical Weather page




This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students.
It was last modified on: Thu, Jul 23 2020 - 2003 UTC
Send comments to: Ryan Lyman